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  • richardmitnick 10:20 am on December 10, 2021 Permalink | Reply
    Tags: "Arecibo data lives on and provides new galaxy insights", , , , EarthSky, Fall relation, , ,   

    From University of Western Australia (AU) and The International Centre for Radio Astronomy Research – ICRAR (AU) via EarthSky : “Arecibo data lives on and provides new galaxy insights” 

    U Western Australia bloc

    From The University of Western Australia (AU)

    and

    ICRAR Logo

    The International Centre for Radio Astronomy Research – ICRAR (AU)

    via

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    EarthSky

    December 5, 2021
    Kelly Kizer Whitt

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    NAIC Arecibo Observatory (PR) (US) before the 2020 collapse. It was built into a natural depression in the landscape, in Puerto Rico. Completed in 1963, it was the world’s largest dish-type radio telescope – cherished by astronomers and widely known in popular culture – for decades. In early 2020, not long before the collapse, China’s Five-hundred-meter Aperture Spherical Radio Telescope, or FAST, had replaced it as the world’s largest. Image via Nature.

    Astronomers suffered a painful loss last year when, on December 1, 2020, the Arecibo radio telescope in Puerto Rico – formerly the world’s largest dish-type radio telescope – collapsed and was decommissioned. Now, a year later, scientists have announced a new paper on galaxy evolution that uses data gathered at Arecibo. So the radio telescope is gone. But the data it gathered during its 57 years in operation live on.

    The MNRAS published the peer-reviewed study on galaxy evolution on December 1,2021.

    Using Arecibo data to study galaxies

    Astronomers from the University of Western Australia and the International Centre for Radio Astronomy Research (ICRAR), based in Perth, Australia) wanted to take a closer look at what’s called the Fall relation in astronomy. S. Michael Fall first proposed this relation in 1983. It shows how the mass of stars in a galaxy correlates to the galaxy’s angular momentum (its rotation, or spin). These astronomers used Arecibo to observe 564 galaxies. They said it was the largest grouping of galaxies ever studied at one time, in the context of learning about the Fall relation. The astronomers said their goal was to understand the correlation, in order to understand how galaxies grow and evolve.

    Astronomer Jennifer Hardwick of the University of Western Australia led the study. She said:

    “Although the Fall relation was first suggested almost 40 years ago, previous research to refine its properties had small samples and was limited in the types of galaxies used.”

    The survey of 564 galaxies enabled astronomers to examine galaxies of varying shapes and ages. And, as often happens, the results challenged what they thought they knew.

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    These are some of the 564 galaxies the Arecibo telescope observed. Scientists used that data to refine the Fall relation, which is the relationship between the mass of stars in a galaxy and its rotation. Image via Jennifer Hardwick/ ICRAR/ GALEX Arecibo SDSS Survey/ DESI Legacy Imaging Survey.

    Unraveling the results

    The results of the study show that the relationship between the mass of stars in a galaxy and its rotation is not what scientists first thought. Different galaxy types display a different relationship between those two elements. Hardwick said:

    “This work challenges astronomers’ current understanding of how galaxies change over their lifetime and provides a constraint for future researchers to develop these theories further.’

    The team is left with more questions about the lifecycle of galaxies. Hardwick continued:

    “Because galaxies evolve over billions of years, we have to work with snapshots of their evolution – taken from different stages of their life – and try to piece together their journey … By developing a better understanding of galaxies’ properties now, we can incorporate these into our simulations to work backwards.”

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    This graph plots galaxies by their specific angular momentum versus their stellar mass (the Fall relation). Analyzing this relationship among many galaxies helps astronomers understand how galaxies formed and evolved. Image: Jennifer Hardwick/ ICRAR.

    Testing the foundations of thought

    Co-author Luca Cortese of the University of Western Australia said:

    “This creates a cycle of technological development, resulting in new discoveries which push for further advances. However, before getting to the new discoveries, it is critical to revisit previous knowledge to make sure that our foundations are correct.

    Since the dawn of extragalactic astronomy, it was clear that angular momentum is a key property for understanding how galaxies form and evolve. But, due to the difficulty of measuring angular momentum, direct observational constraints to our theory have been lacking.

    This work provides an important reference for future studies, offering one of the best measurements of the connection between angular momentum and other galaxy properties in the local universe.”


    Arecibo Observatory – drone and ground view during the collapse & pre-collapse historical footage.

    See the full article here .

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    Please help promote STEM in your local schools.

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    U Western Australia Campus

    ICRAR(AU) is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and The Curtin Institute for Radio Astronomy (CIRA).
    ICRAR(AU) has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO(AU) and The Australian Telescope National Facility,
    ICRAR is:

    Playing a key role in the international The Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    SKA Murchison Widefield Array (AU), Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

    SKA ASKAP Pathfinder Radio Telescope

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

    The University of Western Australia is a public research university in the Australian state of Western Australia. The university’s main campus is in Perth, the state capital, with a secondary campus in Albany and various other facilities elsewhere.

    UWA was established in 1911 by an act of the Parliament of Western Australia and began teaching students two years later. It is the sixth-oldest university in Australia and was Western Australia’s only university until the establishment of Murdoch University (AU) in 1973. Because of its age and reputation, UWA is classed one of the “sandstone universities”, an informal designation given to the oldest university in each state. The university also belongs to several more formal groupings, including The Group of Eight (AU) and The Matariki Network of Universities. In recent years, UWA has generally been ranked either in the bottom half or just outside the world’s top 100 universities, depending on the system used.

    Alumni of UWA include one Prime Minister of Australia (Bob Hawke), five Justices of the High Court of Australia (including one Chief Justice, Robert French, now Chancellor), one Governor of the Reserve Bank (H. C. Coombs), various federal cabinet ministers, and seven of Western Australia’s eight most recent premiers. In 2018 alumnus mathematician Akshay Venkatesh was a recipient of the Fields Medal. As at 2021, the university had produced 106 Rhodes Scholars. Two members of the UWA faculty, Barry Marshall and Robin Warren won Nobel Prizes as a result of research at the university.

    History

    The university was established in 1911 following the tabling of proposals by a royal commission in September 1910. The original campus, which received its first students in March 1913, was located on Irwin Street in the centre of Perth, and consisted of several buildings situated between Hay Street and St Georges Terrace. Irwin Street was also known as “Tin Pan Alley” as many buildings featured corrugated iron roofs. These buildings served as the university campus until 1932, when the campus relocated to its present-day site in Crawley.

    The founding chancellor, Sir John Winthrop Hackett, died in 1916, and bequeathed property which, after being carefully managed for ten years, yielded £425,000 to the university, a far larger sum than expected. This allowed the construction of the main buildings. Many buildings and landmarks within the university bear his name, including Winthrop Hall and Hackett Hall. In addition, his bequest funded many scholarships, because he did not wish eager students to be deterred from studying because they could not afford to do so.

    During UWA’s first decade there was controversy about whether the policy of free education was compatible with high expenditure on professorial chairs and faculties. An “old student” publicised his concern in 1921 that there were 13 faculties serving only 280 students.

    A remnant of the original buildings survives to this day in the form of the “Irwin Street Building”, so called after its former location. In the 1930s it was transported to the new campus and served a number of uses till its 1987 restoration, after which it was moved across campus to James Oval. Recently, the building has served as the Senate meeting room and is currently in use as a cricket pavilion and office of the university archives. The building has been heritage-listed by both the National Trust and the Australian Heritage Council.

    The university introduced the Doctorate of Philosophy degree in 1946 and made its first award in October 1950 to Warwick Bottomley for his research of the chemistry of native plants in Western Australia.

     
  • richardmitnick 10:44 am on December 8, 2021 Permalink | Reply
    Tags: "Dozens of earthquakes rumble off the Oregon coast", , , EarthSky, , ,   

    From EarthSky and The United States Geological Survey (US) : “Dozens of earthquakes rumble off the Oregon coast” 

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    From EarthSky

    and

    The United States Geological Survey (US)

    December 8, 2021
    Deborah Byrd

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    The red dot on the left, surrounded by orange dots, shows the location of the series of earthquakes, which started on December 7, 2021, and is still happening at this writing, in the Pacific Ocean off the coast of Oregon, roughly west of the town of Newport. The inset at right shows a magnified view of the earthquake cluster. Map via Cristina Ortiz López/ USGS Latest Earthquakes.

    Dozens of earthquakes

    The Geological Survey (US) is reporting dozens of small-to-moderate earthquakes that started yesterday (December 7, 2021) and continued through this morning, off the coast of the U.S. state of Oregon. The largest reached magnitude 5.8, according to USGS. Earthquakes in the ocean sometimes cause tsunamis. But no tsunamis were ever expected from these earthquakes, and none are expected at this writing.

    Earthquakes often happen in a series, although it’s unusual to see so many earthquakes (at least 40 by my count) as in this series. They’re of special interest because they’re happening off the coast of a heavily populated region. We often see a dozen or so foreshocks and aftershocks around a primary earthquake. The small-to-moderate quakes off the Oregon coast on December 7-8, 2021, can be considered foreshocks and aftershocks of each other. The terms are relative. It’ll be easiest to sort out which are foreshocks and which are aftershocks (and which are both) once the earthquake series has stopped.

    Has it stopped? The last earthquake as of this writing took place less than an hour ago, at 10:50 UTC this morning, December 8. That is 4:50 a.m. CST; translate UTC to your time. It was a 5.2-magnitude quake. So it’s unknown yet how many more earthquakes might occur in the Pacific, off the Oregon coast, today.

    Earthquakes happen every day

    As of this writing, USGS is showing 80 earthquakes – all around the globe – over the past 24 hours. More than 40 of them happened off the coast of Oregon.

    Earthquakes are common in this part of the world, because western North America borders what’s called the “Ring of Fire”, the most seismically and volcanically active zone in the world.

    The Ring of Fire via Wikimedia Commons.

    The Ring of Fire is a horseshoe-shaped swath – 24,900 miles (40,000 km) long – dotted with seismically active locations. Over 80 per cent of large earthquakes occur along the Ring of Fire, where the Pacific plate is being subducted beneath the surrounding plates.

    Pressure building, pressure releasing

    In a way, an earthquake series like this can be seen as a release of the pressure that’s been building between land plates along this region of the Ring of Fire. Better a lot of little earthquakes than one big one. OregonLive.com said:

    “Small earthquakes strike often near Oregon’s coast, a regular reminder of the cataclysmic earthquake geologists say will happen when the pressure building between the Juan de Fuca and North American plates breaks.

    Per Oregon officials, scientists say there is a 37% chance that a 7.1 magnitude or higher earthquake will happen at the boundary between the two tectonic plates, called the Cascadia Subduction Zone, in the next 50 years.”

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Created by an act of Congress in 1879, the The United States Geological Survey (US) has evolved over the ensuing 125 years, matching its talent and knowledge to the progress of science and technology. The USGS is the sole science agency for the Department of the Interior. It is sought out by thousands of partners and customers for its natural science expertise and its vast earth and biological data holdings.

    On March 3, 1879, we were established by the passing of the Organic Act through Congress. Our main responsibilities were to map public lands, examine geological structure, and evaluate mineral resources. Over the next century, our mission expanded to include the research of groundwater, ecosystems, environmental health, natural hazards, and climate and land use change.

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 11:39 am on December 7, 2021 Permalink | Reply
    Tags: "Asteroid impact monitoring system goes live", Asteroid impact monitoring with Sentry-II, EarthSky   

    From EarthSky : “Asteroid impact monitoring system goes live” 

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    From EarthSky

    December 7, 2021
    Kelly Kizer Whitt

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    JPL/Caltech-NASA(US)’s Center for Near Earth Object Studies (CNEOS) calculated the orbits of 2,200 potentially hazardous objects. This diagram shows the orbits of those objects and helps provide a visual of why we need an improved asteroid impact monitoring system. Note the label of the double asteroid Didymos, the target of NASA’s DART mission. Image via NASA/ JPL-Caltech.

    The National Aeronautics and Space Agency(US) said this week (December 6, 2021) that its newest asteroid monitoring system, an algorithm called Sentry-II, has gone live. It’s now assessing the impact risk of asteroids that pass near Earth. Telescopes surveying the sky have found approximately 28,000 near-Earth asteroids, aka NEAs. With more advanced telescopes coming online, NASA expects scientists to discover many more near-Earth asteroids. So – in keeping with a growing realization over the past several decades (“wow, there are a lot of asteroids out there, and one might strike us!”) – these scientists have now realized they need an improved system to evaluate impact probabilities.

    The Astronomical Journal published a peer reviewed study describing the new technique on Dec. 1, 2021.

    The original Sentry

    Calculating the path of asteroids and how they might impact with the Earth in the future is a challenging activity. Small uncertainties in the asteroids’ positions create big question marks. The Center for Near Earth Object Studies (CNEOS) uses impact monitoring software to calculate the risk. The group, part of NASA’s Jet Propulsion Laboratory, has used software called Sentry to compute the orbit and impact risk of asteroids since 2002.

    Javier Roa Vicens, formerly of JPL and currently at SpaceX, said:

    “The first version of Sentry was a very capable system that was in operation for almost 20 years. It was based on some very smart mathematics: In under an hour, you could reliably get the impact probability for a newly discovered asteroid over the next 100 years – an incredible feat.”

    The new-and-improved Sentry-II

    Sentry-II is an upgrade because it can quickly calculate impact probabilities for all known NEAs. That includes some special cases that the original Sentry could not compute. Sentry-II logs the riskiest objects in the CNEOS Sentry Table.

    Sentry-II’s new capabilities allows NASA to assess all potential impacts, even when the asteroids’ odds of impact are as low as a few chances in 10 million.

    Special case: The Yarkovsky effect

    The path of asteroids is not as simple as merely bending to the will of the sun’s gravity. Another force, though small, can create significant changes in the object’s orbit. As asteroids rotate in space, the sun heats the side facing the asteroid. As it spins away, the hot side cools. When the asteroid cools down, it release a minute amount of energy. This thermal force is the Yarkovsky effect.

    The original Sentry was not able to calculate the Yarkovsky effect. In the short term, the Yarkovsky effect isn’t crucial, but after decades and centuries those small pushes from the sun’s heat add up. Davide Farnocchia of JPL said:

    “The fact that Sentry couldn’t automatically handle the Yarkovsky effect was a limitation. Every time we came across a special case – like asteroids Apophis, Bennu, or 1950 DA – we had to do complex and time-consuming manual analyses. With Sentry-II, we don’t have to do that anymore.”


    OSIRIS-REx Sheds Light on Hazardous Asteroid Bennu.

    Special case: Close encounters with Earth

    Another shortfall the original Sentry had was that it couldn’t always adjust for an asteroid’s altered path after an extreme close encounter with Earth. When an NEA comes too close to Earth, our gravity will deflect it from its original path. Sentry-II can account for tweaked orbits after an asteroid passes close to Earth. Roa Vicens explained:

    “In terms of numbers, the special cases we’d find were a very tiny fraction of all the NEAs that we’d calculate impact probabilities for. But we are going to discover many more of these special cases when NASA’s planned NEO Surveyor mission and the Vera C. Rubin Observatory in Chile go online, so we need to be prepared.”

    NEO Surveyor Infrared Space Telescope depiction

    NSF (US) NOIRLab (US) NOAO (US) Vera C. Rubin Observatory [LSST] Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing NSF (US) NOIRLab (US) NOAO (US) AURA (US) Gemini South Telescope and Southern Astrophysical Research Telescope.

    Asteroid impact monitoring and calculations

    Determining whether an asteroid might impact Earth is a multi-step process. First, the telescopes discover a new NEA. Then, scientists measure the position of the NEA and report this information to the Minor Planet Center. Next, CNEOS uses the data to calculate the asteroid’s most likely orbit. With slight uncertainties in the observed position, the asteroid’s most likely orbit might not be its true orbit. The true orbit lies within a realm of uncertainty, like a cloud of possibilities around the calculated most likely orbit.

    To narrow down the true orbit, the original Sentry made assumptions regarding how this cloud of uncertainty would evolve. Sentry then picked evenly spaced points along a line spanning this region. Each point marked a slightly different location where the asteroid might be.

    Next, Sentry would project the orbits forward in time, watching the virtual asteroids orbit to see if any would come near Earth. For those that did, Sentry made further calculations to “zoom in” and see if any points might impact Earth. If any did intersect with Earth, Sentry estimated the probability of impact. The animation below provides a visualization of this process.


    Apophis.

    Asteroid impact monitoring with Sentry-II

    Sentry-II doesn’t limit itself to a line of points. The new algorithm models thousands of points without making any assumptions. It selects random points across the entire cloud of uncertainty. The algorithm looks at all the possible orbits to determine which ones could hit Earth. Sentry-II takes out some of the guesswork. It also zeroes in on low probability impact scenarios that Sentry may have missed.

    Farnocchia describes it as searching for needles in a haystack. The haystack represents the cloud of uncertainty, with needles representing possible impacts. While Sentry would look for needles in a line in the haystack, Sentry-II throws thousands of magnets at random throughout the haystack. Steve Chesley of JPL said:

    “Sentry-II is a fantastic advancement in finding tiny impact probabilities for a huge range of scenarios. When the consequences of a future asteroid impact are so big, it pays to find even the smallest impact risk hiding in the data.”

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:48 am on December 4, 2021 Permalink | Reply
    Tags: "Tides and the pull of the moon and sun", EarthSky,   

    From EarthSky : “Tides and the pull of the moon and sun” 

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    From EarthSky

    December 3, 2021
    Deborah Byrd

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    This beautiful image of Earth’s watery tides is from EarthSky Facebook friend John Lloyd Griffith.

    High tides following this week’s eclipse?

    We’re having a solar eclipse this week, when the new moon covers the sun. And the moment of greatest eclipse – in the total solar eclipse of December 3-4, 2021 – takes place 0.1 days before the moon reaches perigee, its closest point to Earth for this month. Many will call this month’s new moon a supermoon. The eye couldn’t detect it. But it’s a relatively large-sized moon that will cover the sun during this eclipse. What’s more, in the day or two after the eclipse, people who live along a coastline can expect higher-than-usual tides.

    Some call this sort of tide perigean spring tides. But in recent years, these close new or full moons have come to be called supermoons, some are also calling them supermoon tides. And we’ve also heard the term king tides.

    What are spring tides?

    In most places, but not everywhere, there are two high tides and two low tides a day. The difference in height between high and low tides varies, as the moon waxes and wanes from new to full and back to new again. The moon and sun are primarily responsible for the rising and falling of ocean tides. However, for any particular spot on Earth’s surface, the height of the tides and their fluctuation in time also depend on the shape of your specific beach and the the angle of the seabed leading up to your beach, plus your larger coastline and the prevailing ocean currents and winds.

    Around each new moon and full moon, the sun, Earth, and moon arrange themselves more or less along a line in space. Then the pull on the tides increases, because the gravity of the sun reinforces the moon’s gravity. In fact, the height of the average solar tide is about 50 percent of the average lunar tide.

    Thus, at new moon or full moon, the tide’s range is at its maximum. This is the spring tide: the highest (and lowest) tide. Spring tides are not named for the season. This is spring in the sense of jump, burst forth, rise.

    So spring tides bring the most extreme high and low tides every month, and they always happen – every month – around full and new moon.

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    The 1st full moon of 2018 was also 2018’s closest supermoon. Here it is – at 99.9% illumination – as captured from Karachi, Pakistan, by Talha Zia.

    Why?

    When the new moon or full moon closely aligns with perigee – closest point to Earth in the moon’s orbit – then we have a supermoon and extra-large spring tides.

    In 2018, the January 1-2 full moon closely aligned with perigee to bring forth especially high tides. As it happened, on the day after the January 1-2 supermoon, Storm Eleanor hit Europe with winds of up to 100 mph (160 km/h). The wind and extra-high tides caused flooding, hampered travel, injured and killed people, left tens of thousands of homes without power across the U.K., Ireland and other parts of Europe. No doubt the extra-high tides contributed to the severity of the storm.

    Why are the tides at their strongest around supermoons? It’s simply because the moon is at its closest to Earth, and thus the Earth’s oceans are feeling the pull of the moon’s gravity most powerfully.

    Should you expect these highest tides on the exact day of a supermoon? Probably not. The highest tides tend to follow the supermoon (or any new or full moon) by a day or two.

    Do the most extreme high tides – high tides bringing floods – always occur at supermoons? Not necessarily. It’s when a spring tide coincides with a time of heavy winds and rain – flooding due to a weather extreme – that the most extreme flooding occurs.

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    Gary Peltz in Seattle, Washington, caught these beautiful sunset reflections and the nearly full moon on December 31, 2017.

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    Around each first quarter moon and last quarter moon – when the sun and moon are at a right angle to Earth – the range between high and low tides is least. These are the neap tides. Image via http://www.physicalgeography.net.

    What are neap tides?

    There’s about a seven-day interval between spring tides and neap tides, when the tide’s range is at its minimum. Neap tides occur halfway between each new and full moon – at the first quarter and last quarter moon phase – when the sun and moon are at right angles as seen from Earth. Then the sun’s gravity is working against the gravity of the moon, as the moon pulls on the sea. Neap tides happen approximately twice a month, once around first quarter moon and once around last quarter moon.

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    Earth has two tidal bulges, one on the side of Earth nearest the moon (where the moon’s gravity pulls hardest), and the other on the side of Earth farthest from the moon (where the moon’s gravity pulls least).

    Why two high and two low each day?

    If the moon is primarily responsible for the tides, why are there two high tides and two low tides each day in most places, for example, the U.S. eastern seaboard? It seems as if there should just be one. If you picture the part of Earth closest to the moon, it’s easy to see that the ocean is drawn toward the moon. That’s because gravity depends in part on how close two objects are.

    But then why – on the opposite side of Earth – is there another tidal bulge, in the direction opposite the moon? It seems counterintuitive, until you realize that this second bulge happens at the part of Earth where the moon’s gravity is pulling the least.

    Earth spins once every 24 hours. So a given location on Earth will pass “through” both bulges of water each day. Of course, the bulges don’t stay fixed in time. They move at the slow rate of about 13.1 degrees per day – the same rate as the monthly motion of the moon relative to the stars. Other factors, including the shape of coastlines, etc., also influence the time of the tides, which is why people who live near coastlines like to have a good tide almanac.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 9:34 am on November 17, 2021 Permalink | Reply
    Tags: "Double stars: How to find observe and enjoy", , , , , EarthSky   

    From EarthSky : “Double stars: How to find observe and enjoy” 

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    From EarthSky

    November 17, 2021
    Kelly Kizer Whitt

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    The Big Dipper has 2 parts: a bowl and a handle. Look closely at the handle stars hanging down from the Big Dipper in this photo. Can you spot the double star? Image: Nadiia Ploshchenko via Unsplash.

    Double stars are two stars that appear close together in the sky. They might be physically related or they might only appear to lie together along our line of sight. Double stars that aren’t gravitationally bound systems – but are only located near one another along our line of sight – are optical doubles. Double stars that are gravitationally bound and orbit a common center of mass are true binary star systems. Unlike our sun, scientists believe that most stars in our Milky Way galaxy orbit the galactic center in binary pairs. In fact, some estimates suggest that up to 85% of stars might reside in binary systems.

    Like snowflakes, no two double-star systems are alike. So gazing at them is a lot of fun. You’ll see a huge range of star brightnesses, and a range of different distances between the stars. And sometimes you’ll notice a contrast in colors between the two stars. This post will give you some tips on observing double stars with your eye alone, with binoculars and, if you want to take the plunge, with a small telescope. Read on, and learn to enjoy the sky’s delightful double stars!

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    This chart of the Big Dipper includes a label for Mizar, while its companion star, Alcor, appears next to it without a label.

    Once you get used to spotting double stars, you’ll find them in constellations everywhere. Good luck, and clear skies!

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 12:06 pm on November 9, 2021 Permalink | Reply
    Tags: "The Small Magellanic Cloud orbits our Milky Way", Astronomers believe that the Large and Small Clouds formed around the same time as our Milky Way some 12 to 13 billion years ago., , , , , EarthSky, Henrietta Swan Leavitt-famous for her work on the Cepheid variable stars-studied the Large and Small Magellanic Clouds from Harvard College Observatory in Southern Peru., In his 1756 star map the French astronomer Lacaille called the Magellanic Clouds le Grand Nuage and le Petit Nuage (the Large Cloud and the Small Cloud)., Our home galaxy-the Milky Way is a large spiral. It has some 50 satellite galaxies. But the Large and Small Magellanic Clouds are special., The historical study of the Small Magellanic Cloud dates back to about 1000 BCE., The Large and Small Magellanic Clouds are not visible north of about 17 degrees north latitude.   

    From EarthSky : “The Small Magellanic Cloud orbits our Milky Way” 

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    From EarthSky

    November 6, 2017 [Re-presented 11.9.21]

    Larry Sessions
    Sayali S. Avachat

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    The Small Magellanic Cloud shines just above the middle dome of the Cerro Tololo Inter-American Observatory, along with our Milky Way galaxy and the Large Magellanic Cloud higher above, in this photo taken from Chile in 2018. Image via Joel Goodman.

    NSF NOIRLab NOAO (US) Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.

    Large and Small Magellanic Clouds

    Our home galaxy-the Milky Way is a large spiral. It has some 50 satellite galaxies. But the Large and Small Magellanic Clouds are special.

    lmc Large Magellanic Cloud. ESO’s VISTA telescope reveals a remarkable image of the Large Magellanic Cloud.

    smc Small Magellanic Cloud. 10 November 2005. NASA/ESA Hubble and The STScI Digitized Sky Survey (US) 2.

    They appear relativity large in our sky (for dwarf galaxies) and are visible to the unaided eye on a dark night. Both appear as luminous, bright, fuzzy clouds of stars. You must be far to the south on Earth’s globe – preferably around Earth’s equator, or even better in the Southern Hemisphere – to see them. History usually credits 15th-century Portuguese voyager/astronomer Ferdinand Magellan with “discovering” these hazy star-clouds. And, in later years, the Clouds became known by his name. But, in addition to Magellan, many early navigators used these two small galaxies to find their way across southern oceans. And they were always noticeable in the sky to the people of the Southern Hemisphere, and so figured in early southern legends and myths.

    Best from Southern Hemisphere

    The Large and Small Magellanic Clouds are not visible north of about 17 degrees north latitude. The Small Cloud isn’t visible from North America (except from far southern Mexico), northern Africa, and all of Europe and Asia (except the southernmost regions of India and Southeast Asia).

    But when you go southward on Earth’s globe, the Small Magellanic Cloud comes into view. It’s some 7,000 light-years across. And it’s located only about 200,000 light-years away from our Milky Way, a hop and a skip in astronomical terms. It’s the fourth-closest neighbor to our Milky Way in our Local Group of about 50 galaxies.

    Local Group. Andrew Z. Colvin 3 March 2011

    The Small Magellanic Cloud is smaller and fainter than the Large Magellanic Cloud. Its overall magnitude is about +2. Its brightness is spread over about about 13 square degrees of sky. Therefore, it’s somewhat harder to find than the Large Magellanic Cloud and requires darker skies. From a dark site in Earth’s Southern Hemisphere, the Small Magellanic Cloud stretches about 4 degrees across the sky (about eight times the width of a full moon).

    It’s quite a sight!

    Locating the Small Magellanic Cloud

    The Small Magellanic Cloud is located approximately 20 degrees from the South Celestial Pole, the point in the sky around which all the southern stars turn throughout the night. It’s in the southeast corner of the constellation Tucana the Toucan. It’s about 15 degrees from the bright far-southern star Achernar in the constellation Eridanus the River (see chart below). For reference, a fist-width at arm’s length equals about 10 degrees.

    The Large Magellanic Cloud glows about 20 degrees eastward from the Small Magellanic Clouds.

    The Small Magellanic Cloud appears best late at night in October, around mid-evening in November and December, and in early evening in January. For Northern Hemisphere viewers below 17 degrees north latitude, when the W or M-shaped constellation Cassiopeia the Queen climbs to her highest point in the northern sky, the Small Magellanic Cloud soars to its highest point in the southern sky.

    4
    The Small Magellanic Cloud is found in the southeast corner of the constellation Tucana the Toucan. The nearby bright star is Achernar.

    Small Magellanic Cloud in myth

    European folklore and mythology doesn’t mention the Small Magellanic Cloud, of course. But, in the Southern Hemisphere, Australian Aborigines, the Maori people of New Zealand and the Polynesian people of the South Pacific were familiar with both the Large and Small Clouds. They used them as navigational markers during their oceanic expeditions. They considered these hazy star-clouds predictors of the winds. The website http://www.OzSky.org explains:

    “Many tribes of Australian Aboriginals have ‘dreamtime stories,’ which they have passed down from generation to generation, to explain the universe as they perceive it. One such legend describes the Clouds as the campfires of an old couple, the Jukara. The Jukara relied on other star people to supply them with fish and lily bulbs caught in the Milky Way to survive. The old couple cooked the food over their campfire, which was the star Achernar. The Large Cloud represented the old man while the Small Cloud was the old woman.”

    The Cloud in history

    The historical study of the Small Magellanic Cloud dates back to about 1,000 BCE. But most Europeans first heard of it and the Large Cloud only in the late 15th century, when seafarers traveled south of the equator for exploration and trade. Their most famous association in western history came with the expedition of Ferdinand Magellan on his circumnavigation of the world in 1519-1522. The Large and Small Magellanic Clouds became popularly known as the clouds of Magellan after that time. Still, later star maps didn’t call them that. In Johann Bayer’s famous star atlas Uranometria, first published in 1603, the Clouds’ designations are nubecula major and nubecula minor.

    In his 1756 star map the French astronomer Lacaille called the Magellanic Clouds le Grand Nuage and le Petit Nuage (the Large Cloud and the Small Cloud).

    In the 1830s, English astronomer William Herschel observed the Small Cloud from the Royal Observatory at the Cape of Good Hope in South Africa. He described it as an oval-shaped mass of light with a bright center. He also cataloged several nebulae and star clusters within it. And so the scientific study of the Small Magellanic Cloud began.

    Small Magellanic Cloud science

    A few decades after Herschel’s initial studies, Henrietta Swan Leavitt-famous for her work on the Cepheid variable stars-studied the Large and Small Magellanic Clouds from Harvard College Observatory in Southern Peru. In the early 1900s, she published her work on variable stars in the Small Magellanic Cloud, famously showing the relationship between the periods (cycles) of the stars’ variability and their luminosities. Her study was titled 1777 variables in the Magellanic Clouds. The period-luminosity relationship later became a reliable gauge for astronomers trying to parse the riddle of star and galaxy distances.

    Today, astronomers study the Small and Large Magellanic Clouds for their own sake, especially because the number of satellite galaxies for the Milky Way and other large galaxies is a hot topic in astronomy, related to cosmological theories of the universe as a whole.

    Astronomers believe that the Large and Small Clouds formed around the same time as our Milky Way some 12 to 13 billion years ago. Due to their repeated interaction with our larger Milky Way galaxy, it’s thought that great galactic tides might have caused their irregular shape.

    Both the Large and Small Cloud are rich in dust and gas. Studies with the Hubble Space Telescope have revealed that vast nebulae – or clouds in space – within the Small Cloud might still be forming new stars. These are evident by the dark, intersecting dust lanes seen in the image below.

    The Small Magellanic Cloud is a strong source of X-ray emissions due to the presence of several X-ray binaries.

    The ongoing Dark Energy Survey (US) found a dark stream of interacting matter between the Large and Small Magellanic Clouds. Simulations performed by a team of scientists at The University of Arizona (US) suggested that the two galaxies might be interacting with each other and might eventually merge.

    5
    One of the star clusters in the Small Magellanic Cloud is NGC 346. It’s a star-forming region, featured in the center of this Hubble Space Telescope image within the pink nebula. NGC 346 is 200 light-years across. Exploring NGC 346, astronomers have identified a population of embryonic stars strung along the dark, intersecting dust lanes visible here on the right. Image via APOD/ NASA/ ESA/ Hubble/ Processing by Judy Schmidt.

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:25 am on November 7, 2021 Permalink | Reply
    Tags: "The asteroid belt contains solar system remnants", , , , , EarthSky   

    From EarthSky : “The asteroid belt contains solar system remnants” 

    1

    From EarthSky

    November 3, 2021
    Andy Briggs

    1
    Artist’s concept of our solar system from the sun to the 5th planet, Jupiter. In this illustration, the asteroid belt is the white donut-shaped cloud. Image via Wikimedia Commons.

    Meet the asteroid belt, a place in our solar system where small bodies – mostly rocky and some metallic – orbit the sun. Sometimes scientists call these little worlds minor planets. One (Ceres) is even categorized as a dwarf planet. These objects move mostly between the orbits of our solar system’s 4th planet, Mars, and 5th planet, Jupiter. Astronomers once thought they were leftovers of a rocky planet that Jupiter’s gravity tore apart long ago. Now they think differently. They think the asteroids are likely simply remnants from the creation of our solar system 4.6 billion years ago.

    The word asteroid means starlike. Asteroids got this name because, when astronomers first discovered them in the early 1800s, they thought they looked like stars. And yet their movement was separate from stars. Because they are closer to us, they move against the starry backdrop. This showed asteroids to be something other than stars.

    Asteroids by the millions

    While the graphic may make it seem like the asteroid belt is teeming with debris, if you lumped all the material together it would only create a body smaller than Earth’s moon.

    The asteroid belt contains objects that vary wildly in size. It has one to two million asteroids more than half a mile (about a km) across. Plus, the asteroid belt contains untold millions of smaller ones, some probably no bigger than pebbles. In 1801, the astronomer Giuseppe Piazzi spotted the first asteroid to be discovered, which is also the biggest object in the asteroid belt. It is 1 Ceres, which measures some 587 miles (945 km). The International Astronomical Union has reclassified Ceres from an asteroid to a dwarf planet.

    Distances in the asteroid belt

    Outer space is vast. And thus, despite there being many millions (possibly billions) of objects in the asteroid belt, the average distance between them is 600,000 miles (about a million km). This means that spacecraft can fly through the asteroid belt without colliding with any asteroids. (Although, obviously, a chance collision is never completely out of the realm of possibility and bad luck.) The asteroid belt is certainly nothing like the densely packed fields depicted in fantasies such as “Star Wars” and its ilk.

    Standing on any asteroid in the belt, you would likely be unable to see any other asteroids, because of their distance.

    The asteroid belt lies between 2.2 and 3.2 astronomical units (AU) from our sun. One AU is the distance between the Earth and sun. So the width of the asteroid belt is roughly 1 AU, or 92 million miles (150 million km).

    Its thickness is similarly about 1 AU.

    Asteroids in and out of the main belt

    The asteroid belt is often called the main belt to distinguish it from other, smaller groups of asteroids in the solar system such as the Lagrangians (for example, Trojan asteroids orbiting in Jupiter’s orbit around the sun) and Centaurs in the outer solar system [see graphic].

    What scientists once thought was a homogeneous belt is now known to be slightly more complicated. There are different and distinct zones within the main belt asteroids, especially at its edges, where astronomers now recognize the Hungaria group at the inner edge and the Cybele asteroids at the outer. Toward the middle of the belt there is the highly inclined Phocaea family.

    In addition, astronomers have established that the age of asteroids in the main belt also varies. They’ve now classified several asteroid groupings by their age including the Karin family, a group of about 90 main-belt asteroids that share an orbit and may have come from a single object an estimated 5.7 million years ago. And there is the Veritas family, from an estimated 8.3 million years ago. A very recent group is the Datura family, dating from a collision just 530,000 years ago.

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:09 am on November 7, 2021 Permalink | Reply
    Tags: "DART mission to hit and move an asteroid", EarthSky,   

    From The National Aeronautics Space Agency (US) via EarthSky : “DART mission to hit and move an asteroid” 

    From The National Aeronautics Space Agency (US)

    via

    1

    EarthSky

    November 6, 2021
    Kelly Kizer Whitt

    National Aeronautics Space Agency(US) DART in space depiction.

    National Aeronautics and Space Administration(US) NASA Double Asteroid Redirection Test (DART) Mission (US) schematic.


    DART, NASA’s First Planetary Defense Test Mission. Credit: The Johns Hopkins University Applied Physics Laboratory (US).

    DART mission targets Didymos B

    NASA will soon launch its first planetary defense test mission, called DART (Double Asteroid Redirect Test). The launch window will open on November 24, 2021. The goal of the DART mission is to strike a small asteroid and minutely change its orbit. In recent decades, it’s become clear that asteroids do have the potential to strike Earth and cause damage. The DART mission is a test run for when Earth is faced with an incoming asteroid that’s threatening our planet. DART will arrive at its target asteroid in late 2022 with a impact, becoming the first Earth mission in our history to deflect an asteroid.

    DART’s target asteroid is a moonlet of a larger asteroid. The large asteroid is Didymos, 2,500 feet (780 m) in diameter. Its companion, Didymos B (or, sometimes, Dimorphos) is 525 feet (160 m) in diameter. That’s more typical of the size asteroid that might unexpectedly threaten Earth, these astronomers said. That’s because the larger asteroids are easier to see, and their orbits are better known.

    Didymos is itself classified as a Potentially Hazardous Asteroid (PHA). By definition, such asteroids have a minimum orbit intersection distance of 0.05 AU (Earth-sun units of distance) or less and an absolute magnitude of +22 or less. In other words, all asteroids that can’t get any closer to the Earth than 0.05 Earth-sun distances – roughly 4,650,000 miles (7,480,000 km) – or are smaller than about 500 feet (140 m) in diameter are not considered PHAs.

    Being a Potentially Hazardous Asteroid does not mean Didymos is on a collision course with Earth. It is not. But, in 2003, Didymos did pass only slightly closer than the minimum distance for PHAs. It passed only 0.048 AU from Earth. It was still millions of miles away from us.

    2
    These 14 radar images are from November 24, 2003, when Didymos and its moonlet Didymos B passed relatively close to Earth. Astronomers used the now-wrecked Arecibo telescope in Puerto Rico to perform radar imaging. Image via Arecibo/ NASA.

    NAIC Arecibo Observatory(US) operated by University of Central Florida(US), Yang Enterprises(US) and Ana G. Méndez University[Universidad Ana G. Méndez, Recinto de Cupey](PR) Altitude 497 m (1,631 ft), which has now collapsed.

    This is only a test

    But this mission is a test. It’s only a test of what might someday become a full-blown planetary defense program. Didymos and its moonlet Didymos B are not a threat to Earth at this time.

    The DART spacecraft is on a kamikaze mission to Didymos (NASA calls it a kinetic impactor mission). It’ll deliberately crash itself into the moonlet at a speed of approximately 4.1 miles/s (6.6 km/s). DART will use an onboard camera (named DRACO) and sophisticated autonomous navigation software to measure the size and shape of Didymos B and to provide detailed views of the site where it will slam into the asteroid.

    I know what you’re thinking. If NASA pushes Didymos B off its regular orbit, could it cause the moonlet – or its larger parent asteroid Didymos – into a new path that could possibly be a bigger threat to Earth? These scientists said no, neither Didymos nor its moonlet will become a threat to us because of DART. But that doesn’t mean debris from the impact won’t hit Earth. More on that in a moment.

    his test by NASA is an attempt to keep us safe. The effect of DART on Didymos B will be minimal, but still enough for scientists to measure. As NASA said:

    “Scientists think the collision will change the speed of the moonlet by a fraction of one percent and alter its orbital period around the larger asteroid by several minutes — enough to be observed and measured by telescopes on Earth.”

    The idea is that, if we were ever to discover a small asteroid on a collision course with Earth, we’d have had some practice in deflecting asteroids away from us.

    Meteorites from DART

    Here’s a cool aspect of the DART mission. Some scientists believe bits of the debris will eventually hit Earth. A March 23, 2020, paper in The Planetary Science Journal said:

    “Because the closest point of approach of Didymos to Earth’s orbit is only 6 million km (about 16 times the Earth–moon distance), some ejected material will make its way sooner or later to our planet, and the observation of these particles as meteors would increase the scientific payout of the DART mission.

    The DART project may also represent the first human-generated meteoroids to reach Earth.”

    Didymos A and Didymos B

    The asteroid Didymos A and its companion Didymos B were unknown until 1996, when the Spacewatch survey at Kitt Peak National Observatory in Arizona picked up the pair.

    Didymos B snuggles close to its parent, orbiting at a distance of just over a half mile or 1 kilometer. It takes the moonlet about 12 hours to complete one orbit of Didymos. Like our moon, the moonlet is tidally locked to Didymos, always showing the asteroid the same face.

    At present, scientists said, the Didymos binary asteroid is being intensely observed using telescopes on Earth. They want to obtain precise measurements of its properties before DART arrives.

    DART will launch aboard a SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California. After separation from the launch vehicle and over a year of cruise it will intercept Didymos’ moonlet in late September 2022, when the Didymos system is within about 7 million miles (11 million km) of Earth. The relatively close distance between Earth and the asteroid at that time will let scientists observe the asteroid at the time of impact with ground-based telescopes and planetary radar.

    They’ll be watching and hoping to measure a change in momentum, imparted to the moonlet.


    The Double Asteroid Redirection Test (DART): Hitting an Asteroid Head On.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.
    Stem Education Coalition

    The The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra,
    Spitzer , and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 9:48 am on November 5, 2021 Permalink | Reply
    Tags: "Revealing hidden alien oceans with chemistry", , , EarthSky, , , Thermochemical equilibrium (chemical equilibrium)   

    From NASA JPL-Caltech via EarthSky : “Revealing hidden alien oceans with chemistry” 

    From NASA JPL-Caltech

    via

    1

    EarthSky

    November 5, 2021
    Paul Scott Anderson

    1
    Sub-Neptunes are planets that are smaller than Neptune but larger than Earth. They are typically between 1.7 and 3.5 times the diameter of Earth. A new NASA study says that astronomers can detect oceans on some of these worlds by analyzing the chemistry of their atmospheres. Image via NASA/ JPL-Caltech (US).

    Our planet Earth is the only world in our solar system with liquid water on its surface. In this solar system, Earth’s oceans are unique. But scientists think there are many more ocean worlds elsewhere in our Milky Way galaxy. In late October 2021, NASA released a new study suggesting that scientists can find hidden alien oceans on distant exoplanets via the use of chemistry. The study showed that, on worlds that have oceans, the chemical makeup of the atmosphere is distinctly different, as compared to worlds lacking oceans on their surfaces.

    The new peer-reviewed research paper was published in The Astrophysical Journal Letters.

    Using chemistry to find hidden alien oceans

    The new study proposes that astronomers could detect oceans on exoplanets by analyzing the chemistry of their atmospheres. Generally, this could apply to Earth-sized worlds, super-Earths or even some sub-Neptunes (any planet with a radius smaller than Neptune but larger than Earth). The paper focuses on planets that are between 1.7 and 3.5 times the diameter of Earth. Telescopes with spectrometers, including the upcoming James Webb Space Telescope (JWST), can identify the chemical makeup of the atmospheres of some of these planets. They can find gases such as oxygen, carbon dioxide or methane, which could be hints of life.

    That’s exciting, but such chemical analyses can reveal other things about these planets, too. It could find evidence for oceans, which also has big implications for habitability, of course.


    Exoplanet Types: Worlds Beyond Our Solar System.

    Too hot for liquid water or just right?

    At least in some cases, those telescopes can help determine whether there is liquid water on the surface of any of these planets. More specifically, by analyzing the chemicals in the atmosphere, scientists can estimate whether the surface temperature is too hot for liquid water.

    So which chemicals might be indicative of an ocean beneath the clouds? One finding would be carbon dioxide and nitrogen in the atmosphere, where the nitrogen molecules consist of two nitrogen atoms. Why is that significant? It would be evidence that the planet’s atmosphere is cooler and thinner, ie. more like those on terrestrial planets like Earth. It would indicate that thermochemical equilibrium (chemical equilibrium) has not occurred on that planet.

    In thermochemical equilibrium, the chemistry of the atmosphere is altered. This happens when the planet’s atmosphere is composed primarily of hydrogen, which is common for sub-Neptune worlds. In those cases, the carbon and nitrogen are in the form of methane and ammonia, and the atmosphere is significantly thicker.

    In those scenarios, the thick atmosphere, like the ones on the gas and ice giants in our solar system, traps heat. Thermochemical equilibrium will occur when the temperature reaches 1,430 degrees F (770 degrees C). That’s too hot to support liquid-water oceans.

    Missing ammonia

    Another key indicator for possible oceans is that something is missing in the atmosphere: ammonia. Because ammonia is highly soluble in water, it would be nearly non-existent on ocean planets. So planets with massive oceans should have virtually no ammonia in their atmospheres. The pH (acidity) level of the ocean, however, would also affect how much ammonia were still present, if any.

    Also, there should be more carbon dioxide than carbon monoxide on ocean worlds. If there were both a lack of ammonia and an excess of carbon dioxide in a planet’s atmosphere, this would be compelling evidence for an ocean world. As Renyu Hu at NASA’s Jet Propulsion Laboratory (JPL), who led the new study, stated:

    “If we see the signatures of thermochemical equilibrium, we would conclude that the planet is too hot to be habitable. Vice versa, if we do not see the signature of thermochemical equilibrium and also see signatures of gas dissolved in a liquid-water ocean, we would take those as a strong indication of habitability.”

    Hu continued:

    “We don’t have direct observational evidence to tell us what the common physical characteristics for sub-Neptunes are. Many of them may have massive hydrogen atmospheres, but quite a few could still be ‘ocean planets’. I hope this paper will motivate many more observations in the near future to find out.”

    Future observations

    NASA’s James Webb Space Telescope (JWST), due to launch on December 18, will have a spectrometer capable of analyzing the atmospheres of some of these worlds.

    National Aeronautics Space Agency(USA)/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) Webb Infrared Space Telescope(US) James Webb Space Telescope annotated. Scheduled for launch in October 2021 delayed to December 2021.

    As noted in the paper:

    “These gases lead to distinctive features in the planet’s transmission spectrum, and a moderate number of repeated transit observations with the James Webb Space Telescope should tell apart a small atmosphere vs. a massive one on planets like K2-18 b. This method thus provides a way to use near-term facilities to constrain the atmospheric mass and habitability of temperate sub-Neptune exoplanets.”

    In other words, JWST will be able to identify signs in the atmospheres that can reveal ocean-supporting planets. It will be exciting to see what JWST finds in the months and years ahead!

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

    NASA JPL-Caltech Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

     
  • richardmitnick 11:04 am on October 16, 2021 Permalink | Reply
    Tags: "Parker Solar Probe has a Venus flyby today", EarthSky, ,   

    From The Johns Hopkins University Applied Physics Lab (US) via EarthSky : “Parker Solar Probe has a Venus flyby today” 

    1
    This was the Parker Solar Probe’s location on September 30, 2021, when the spacecraft performed a short maneuver to set it on course for the October 16 Venus flyby. The green lines mark the spacecraft’s path since it launched on Aug. 12, 2018. The red loops show the probe’s future orbits, bringing it progressively closer to the sun. Image: Yanping Guo via The National Aeronautics and Space Agency (US)/ Johns Hopkins APL.

    Parker Solar Probe flyby and gravity assist

    Parker Solar Probe will perform its next Venus flyby on October 16, 2021. The spacecraft made a short preparatory maneuver on September 29. This maneuver changed the craft’s speed by 9.7 centimeters per second, or less than a third of a mile per hour. That slight change was critical for placing the craft on course for Saturday’s Venus gravity assist, when it will use the planet’s gravity to swing toward its 10th close approach to the sun.

    The September 29 maneuver was monitored from the mission operations center at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. APL also designed and built the Parker Solar Probe and said it is:

    “… healthy and its systems are operating normally. The spacecraft completed its 9th solar encounter on August 15, 2021, at closest approach coming within 6.5 million miles (10.4 million km) of the sun’s surface. The upcoming Venus gravity assist will send the spacecraft even closer to the sun’s blazing surface – about 5.6 million miles (9 million km) – on November 21.

    Assisted by two additional Venus flybys, Parker Solar Probe will eventually come within 4 million miles (6.4 million km) of the solar surface in late 2024.”

    Seven-year mission to touch the sun

    In all, the probe has 24 scheduled orbits around the sun during its seven-year mission. During this time, NASA likes to say, the probe will “touch” the sun, that is, fly within the sun’s atmosphere. During each of its sweeps past the sun, NASA said, the Parker Solar Probe will break its own nearness records to the sun.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Johns Hopkins University campus

    JHUAPL campus

    Founded on March 10, 1942—just three months after the United States entered World War II— The Johns Hopkins University Applied Physics Lab (US) -was created as part of a federal government effort to mobilize scientific resources to address wartime challenges.

    The Applied Physics Lab was assigned the task of finding a more effective way for ships to defend themselves against enemy air attacks. The Laboratory designed, built, and tested a radar proximity fuze (known as the VT fuze) that significantly increased the effectiveness of anti-aircraft shells in the Pacific—and, later, ground artillery during the invasion of Europe. The product of the Laboratory’s intense development effort was later judged to be, along with the atomic bomb and radar, one of the three most valuable technology developments of the war.

    On the basis of that successful collaboration, the government, The Johns Hopkins University, and APL made a commitment to continue their strategic relationship. The Laboratory rapidly became a major contributor to advances in guided missiles and submarine technologies. Today, more than seven decades later, the Laboratory’s numerous and diverse achievements continue to strengthen our nation.

    The Applied Physics Lab continues to relentlessly pursue the mission it has followed since its first day: to make critical contributions to critical challenges for our nation.

    Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

    The Johns Hopkins University (US) is a private research university in Baltimore, Maryland. Founded in 1876, the university was named for its first benefactor, the American entrepreneur and philanthropist Johns Hopkins. His $7 million bequest (approximately $147.5 million in today’s currency)—of which half financed the establishment of the Johns Hopkins Hospital—was the largest philanthropic gift in the history of the United States up to that time. Daniel Coit Gilman, who was inaugurated as the institution’s first president on February 22, 1876, led the university to revolutionize higher education in the U.S. by integrating teaching and research. Adopting the concept of a graduate school from Germany’s historic Ruprecht Karl University of Heidelberg, [Ruprecht-Karls-Universität Heidelberg] (DE), Johns Hopkins University is considered the first research university in the United States. Over the course of several decades, the university has led all U.S. universities in annual research and development expenditures. In fiscal year 2016, Johns Hopkins spent nearly $2.5 billion on research. The university has graduate campuses in Italy, China, and Washington, D.C., in addition to its main campus in Baltimore.

    Johns Hopkins is organized into 10 divisions on campuses in Maryland and Washington, D.C., with international centers in Italy and China. The two undergraduate divisions, the Zanvyl Krieger School of Arts and Sciences and the Whiting School of Engineering, are located on the Homewood campus in Baltimore’s Charles Village neighborhood. The medical school, nursing school, and Bloomberg School of Public Health, and Johns Hopkins Children’s Center are located on the Medical Institutions campus in East Baltimore. The university also consists of the Peabody Institute, Applied Physics Laboratory, Paul H. Nitze School of Advanced International Studies, School of Education, Carey Business School, and various other facilities.

    Johns Hopkins was a founding member of the American Association of Universities (US). As of October 2019, 39 Nobel laureates and 1 Fields Medalist have been affiliated with Johns Hopkins. Founded in 1883, the Blue Jays men’s lacrosse team has captured 44 national titles and plays in the Big Ten Conference as an affiliate member as of 2014.

    Research

    The opportunity to participate in important research is one of the distinguishing characteristics of Hopkins’ undergraduate education. About 80 percent of undergraduates perform independent research, often alongside top researchers. In FY 2013, Johns Hopkins received $2.2 billion in federal research grants—more than any other U.S. university for the 35th consecutive year. Johns Hopkins has had seventy-seven members of the Institute of Medicine, forty-three Howard Hughes Medical Institute Investigators, seventeen members of the National Academy of Engineering, and sixty-two members of the National Academy of Sciences. As of October 2019, 39 Nobel Prize winners have been affiliated with the university as alumni, faculty members or researchers, with the most recent winners being Gregg Semenza and William G. Kaelin.

    Between 1999 and 2009, Johns Hopkins was among the most cited institutions in the world. It attracted nearly 1,222,166 citations and produced 54,022 papers under its name, ranking No. 3 globally [after Harvard University (US) and the Max Planck Society (DE) in the number of total citations published in Thomson Reuters-indexed journals over 22 fields in America.

    In FY 2000, Johns Hopkins received $95.4 million in research grants from the National Aeronautics and Space Administration (US), making it the leading recipient of NASA research and development funding. In FY 2002, Hopkins became the first university to cross the $1 billion threshold on either list, recording $1.14 billion in total research and $1.023 billion in federally sponsored research. In FY 2008, Johns Hopkins University performed $1.68 billion in science, medical and engineering research, making it the leading U.S. academic institution in total R&D spending for the 30th year in a row, according to a National Science Foundation (US) ranking. These totals include grants and expenditures of JHU’s Applied Physics Laboratory in Laurel, Maryland.

    The Johns Hopkins University also offers the “Center for Talented Youth” program—a nonprofit organization dedicated to identifying and developing the talents of the most promising K-12 grade students worldwide. As part of the Johns Hopkins University, the “Center for Talented Youth” or CTY helps fulfill the university’s mission of preparing students to make significant future contributions to the world. The Johns Hopkins Digital Media Center (DMC) is a multimedia lab space as well as an equipment, technology and knowledge resource for students interested in exploring creative uses of emerging media and use of technology.

    In 2013, the Bloomberg Distinguished Professorships program was established by a $250 million gift from Michael Bloomberg. This program enables the university to recruit fifty researchers from around the world to joint appointments throughout the nine divisions and research centers. Each professor must be a leader in interdisciplinary research and be active in undergraduate education. Directed by Vice Provost for Research Denis Wirtz, there are currently thirty two Bloomberg Distinguished Professors at the university, including three Nobel Laureates, eight fellows of the American Association for the Advancement of Science (US), ten members of the American Academy of Arts and Sciences, and thirteen members of the National Academies.

     
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