Tagged: space.com Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 1:57 pm on July 31, 2015 Permalink | Reply
    Tags: , , , , , space.com   

    From Space.com via SETI Institute: “SETI Targets Kepler-452b, Earth’s ‘Cousin,’ in Search for Alien Life” 


    SETI Institute

    q

    July 31, 2015
    Nola Taylor Redd, SPACE.com Contributor

    Temp 0
    An artist’s concept of the alien Kepler-452b in orbit around its star Kepler-452, which is located 1,400 light-years from Earth. NASA has billed the potentially habitable planet as Earth’s bigger, older cousin.

    Scientists with the SETI (Search for Extraterrestrial Intelligence) Institute have already begun targeting Earth’s “older cousin,” Kepler 452b, the first near-Earth-size world found in the habitable zone of a sun-like star.

    NASA announced the discovery of Kepler-452b last week, billing the planet as the closest thing yet to an Earth 2.0 beyond Earth’s solar system. Researchers have used the Allen Telescope Array [ATA], a collection of 42 radio antennas in northern California, to study the planet for radio signals that could indicate the presence of intelligent extraterrestrial life.

    SETI ATA
    ATA

    So far, the antennas haven’t tuned into any broadcasts.

    “That’s no reason to get discouraged,” Seth Shostak, senior astronomer with the SETI Institute, which is based in Mountain View, California, said during a July 26 webcast by the Slooh Community Observatory.

    “Bacteria, trilobites, dinosaurs—they were here but they weren’t building radio transmitters,” he said.

    Tens of billions of worlds

    Kepler-452 is a sunlike star, located 1,400 light-years from Earth, in the constellation Cygnus. The star’s newly discovered planet, Kepler-452b, has a radius approximately 1.6 times larger than Earth’s. The mass of the planet and its density, which would indicate its composition, have been a bit more challenging to pin down.

    “We would love to be able to do a direct mass measurement so we could measure density,” said Jon Jenkins of NASA’s Ames Research Center in Moffett Field, California, lead author on the paper that identified Kepler-452b. “That would be a big clue as to whether this is a rocky world or a water world or a gassy world.”

    Instead, the team relied on statistics to conclude that the planet has a “better than even chance” of having a composition similar to Earth.

    “The odds slightly favor this planet being rocky,” Jenkins said.

    Based on its size, orbit and star, Kepler-452b is the closest analogue to Earth yet discovered, its discoverers and NASA officials have said.

    Kepler-452b orbits its star once every 385 days, about three weeks longer than Earth takes to travel around the sun. This orbit places the planet squarely in what scientists call the “habitable zone,” the region around a star where liquid water could exist at a planet’s surface. Water is thought to be a key requirement for life to evolve, so Kepler-452b is one of the best potentially habitable worlds found to date.

    SETI Institute researchers are using the Allen Telescope Array, a collection of 6-meter (20 feet) telescopes in the Cascade Mountains of California, to observe Kepler-452b. So far, the array has observed the exoplanet on over 2 billion frequency bands, with no result. The telescopes will continue to observe over a total of 9 billion channels, searching for signals of alien intelligence.

    “There are three ways to find life in space,” Shostak said. The first is to “go there and look”, as humans are doing on Mars and the moons of the solar system, he said. For planets like Kepler-452b, which lie so far from the solar system, such a trip would be a challenge with today’s technology.

    The second is to “build big telescopes and analyze the light bouncing off of a planet,” Shostak said. NASA’s Hubble Space Telescope has already begun to probe the atmospheres of distant planets.

    NASA Hubble Telescope
    NASA/ESA Hubble

    However, Jenkins said, the host star is too dim to allow for this sort of examination with either Hubble or its successor, the James Webb Space Telescope.

    NASA Webb Telescope
    Webb

    The third way to find life in space is to search for signals that could indicate intelligence. “That’s what SETI does,” Shostak said.

    Both Shostak and Jenkins emphasized that what makes Kepler-452b truly important is what it indicates for the wide population of planets beyond the solar system. Before this planet’s discovery, no sun-like stars had been found to host rocky worlds in their habitable zones, making Earth fairly unique in the known galaxy. Although statistics suggested many such planets orbited other stars, no such worlds had been observed with modern instruments.

    Jenkins noted that the existence of Kepler-452b suggests similar finds will be made in the near future.

    “We have a really good opportunity in the future to find a similar-size planet in a similar-size orbit about a similar star far closer to us,” he said.

    Unlike the distant exoplanet, a closer exoplanet could have its atmosphere probed for potential signatures of life.

    “What you really want to know is what [fraction] of planets could be habitable,” Shostak said. He added that Kepler-452b suggests that fraction is perhaps one in five, or even one in three.

    “There could be tens of billions of such worlds in the galaxy,” Shostak said.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

     
  • richardmitnick 10:50 am on July 19, 2015 Permalink | Reply
    Tags: , , , space.com   

    From SPACE.com: “Newfound Alien Planet Is One of the Farthest Ever Detected” 

    space-dot-com logo

    SPACE.com

    April 16, 2015
    Elizabeth Howell

    1
    NASA’s Spitzer Space Telescope co-discovered an exoplanet more than 13,000 light-years from Earth, far from where most known exoplanets are Credit: NASA/JPL-Caltech

    A NASA telescope has co-discovered one of the most distant planets ever identified: a gas giant about 13,000 light-years away from Earth.

    The technique used by the Spitzer Space Telescope, called microlensing, is so new that it has only yielded about 30 planet discoveries so far. But the telescope’s potential for finding far-away worlds is vast, NASA said in a statement. And as astronomers begin to chart the location of these distant bodies, it will provide a sense of where planets are distributed in Earth’s Milky Way galaxy.

    NASA Spitzer Telescope
    Spitzer

    “We don’t know if planets are more common in our galaxy’s central bulge or the disk of the galaxy, which is why these observations are so important,” Jennifer Yee, of the Harvard-Smithsonian Center for Astrophysics, said in a NASA statement. Yee is the lead author on one of three new papers describing the discovery.

    2
    An infographic showing how NASA’s Spitzer Space Telescope works with ground-based telescopes to find distant exoplanets, using a technique called microlensing. Credit: NASA/JPL-Caltech

    Magnified starlight

    Microlensing happens when one star travels in front of another from the perspective of an observer (in this case, on Earth). When this happens, the gravity of the star in front magnifies the light of the star behind it, acting like a lens. Should the star in front have a planet, that planet would create a “blip” during the magnification, NASA said in the statement.

    The challenge, however, is pinning down how far away the closer star (and its planet) is from Earth. Microlensing tends to magnify the star behind, but usually the star in front is invisible to observers. That’s why about half of the 30 or so planets found with microlensing (including a few Tatooine-like planets) are at unknown distances from Earth.

    To overcome the distance problem, astronomers used the Spitzer telescope in concert with the Polish Optical Gravitational Lensing Experiment (OGLE) Warsaw Telescope at the Las Campanas Observatory in Chile. OGLE routinely does microlensing investigations, but for Spitzer, this was the first time the long-running telescope had successfully used the technique to find a planet.

    OGLE Warsaw Telescope
    OGLE Warsaw telescope interior
    Polish Optical Gravitational Lensing Experiment (OGLE) Warsaw Telescope

    Quick telescope work

    Prominent telescopes like Spitzer are usually fully booked with other astronomical observations. This makes it difficult to respond quickly when the astronomical community is alerted about a microlensing event, which lasts only 40 days on average. Spitzer officials, however, have worked to do these observations as early as three days after an event is announced.

    The new planet’s microlensing event was quite long, roughly 150 days.

    Spitzer orbits the sun from a position behind Earth (about 128 million miles or 207 million kilometers away from its home planet, further than the Earth-sun distance). This vast distance from its home planet means the telescope sees microlensing events occur at a slightly different time than do telescopes on Earth.

    Spitzer spotted the “blip” in the magnification about 20 days before OGLE did. By comparing the delay between what Spitzer and OGLE saw, astronomers could calculate the planet’s distance from Earth. Once they knew that measure, they were able to estimate the planet’s mass, which is roughly half that of Jupiter.

    This is the first time Spitzer found a planet using microlensing, but it comes after 22 previous attempts with OGLE and other telescopes on the ground. Astronomers forecast Spitzer will examine 120 more microlensing events this summer.

    So far, microlensing has helped astronomers find 30 planets at distances as far as 25,000 light-years away from Earth. That’s in addition to the more than 1,000 closer worlds discovered by the planet-hunting Kepler space telescope and ground-based observatories using other techniques. Astronomers are using the microlensing events to seek out planets in the central “bulge” of the Milky Way, a spot where stars are more densely packed and tend to cross more often.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 9:20 am on July 19, 2015 Permalink | Reply
    Tags: , , space.com   

    From SPACE.com: “Bizarre Cometlike Alien Planet Is First of Its Kind” 

    space-dot-com logo

    SPACE.com

    June 24, 2015
    Charles Q. Choi,

    1
    This artist’s impression shows exoplanet GJ 436b, which is surrounded by a massive gas cloud that streams behind the planet like a comet’s tail for millions of miles. Credit: Mark Garlick/University of Warwick

    A Neptune-size planet appears to be masquerading as a comet, with a gargantuan stream of gas flowing behind it like a comet’s tail.

    The bizarre find is the first of its kind ever discovered by astronomers. The strange, cometlike planet, known as GJ 436b, is orbiting a red dwarf star and is about 22 times as massive as Earth. Astronomers detected the giant gas cloud around the planet using NASA’s Hubble Space Telescope and Chandra X-ray Observatory.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NASA Chandra Telescope
    NASA/Chandra

    “I was astonished by the mere size of the cloud of gas escaping from the planet,” said study lead author David Ehrenreich, an astronomer at the observatory of the University of Geneva in Switzerland.

    GJ 436b, located about 33 light-years from Earth in the constellation Leo, is a kind of world known as a warm Neptune. Such planets, at about 10 to 20 times the mass of Earth, are about the mass of “cold Neptunes” such as Uranus — and, naturally, Neptune — but they are as close, or closer, to their stars than Mercury is to our sun. With an orbit of only about 3 million miles (4.8 million kilometers), “GJ 436b is 33 times closer to its star than Earth is to the sun, and 13 times closer than Mercury,” Ehrenreich told Space.com.

    The cloud of gas around GJ 436b, made up mostly of hydrogen, has a circular head that surrounds GJ 436b, and a tail trailing behind the planet. The diameter of the head is about 1.8 million miles (3 million km), or five times the width of the host star, which is about half that of the sun, Ehrenreich said. The length of the tail is uncertain, because the research team’s observations do not cover it entirely, but their computer models suggest it could be about 9.3 million miles (15 million km) long

    Although prior research has predicted that other gas giants should be blowing off cometlike tails, based on how hot they must be due to their proximity to their stars, “GJ 436b is the first planet for which a cometlike tail is confidently detected,” Ehrenreich said. (A previous study revealed indirect evidence of a rocky world that appears to be disintegrating around its host star, creating a cometlike tail of material behind the planet. That study used data from NASA’s Kepler space telescope, which observed scattering of the light from the planet’s host star.)

    NASA Kepler Telescope
    NASA/Kepler

    The scientists estimated that GJ 436b is currently blowing off up to 1,000 tons of gas per second. This means that GJ 436b is currently losing about 0.1 percent of its atmosphere every billion years, which is far too slow a rate to deplete its atmosphere in the lifetime of its parent red dwarf star. However, when the star was more active in its infancy, the researchers estimated that GJ 436b could have lost 10 percent or more of its atmosphere during its first billion years.

    Recently, another team of researchers suggested that GJ 436b might possess a helium-rich sky depleted of hydrogen. “However, in order to be really hydrogen-poor and helium-rich, the atmosphere of GJ 436b should have represented a very small fraction of the planet[‘s] initial mass, around one-thousandth,” Ehrenreich said. “In such a case, the whole atmosphere would have been gone today, which as we measure is not the case.”

    Ehrenreich noted that the Kepler spacecraft, as well as NASA’s upcoming TESS space mission and the European Space Agency’s future CHEOPS and PLATO spacecraft “are poised to find thousands of system like GJ 436 in the coming years.” This suggests that many other planets with cometlike tails could soon be discovered.

    NASA TESS
    NASA/TESS

    ESA CHEOPS
    ESA/CHEOPS

    ESA PLATO
    ESA/PLATO

    Temp 0
    Artist’s concept of the exoplanet GJ 436b, which is apparently surrounded by a massive gas cloud that streams behind the planet like a comet’s tail for millions of miles. Credit: D. Ehrenreich / V. Bourrier (Université de Genève) / A. Gracia Berná (Universität Bern)

    The scientists now plan to investigate less massive planets, such as “super-Earths” and “mini-Neptunes” to see if they might also have puffy atmospheres and cometlike tails.

    “We’re going to study one such object in the course of next year with Hubble, and have proposed to observe several more,” Ehrenreich said.

    The scientists detailed their findings online today (June 24) in the journal Nature.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 11:32 am on July 18, 2015 Permalink | Reply
    Tags: , , Hypervelocity stars, space.com   

    From SPACE.com: “Fastest Star in the Galaxy Has a Strange Origin” 

    space-dot-com logo

    SPACE.com

    March 05, 2015
    Calla Cofield

    The fastest-known star in the Milky Way is on a path out of the galaxy, and new research suggests it was a supernova that gave it the boot.

    The runaway star, US 708, is traveling at 745 miles per second (1200 km/s) — that’s 26 million miles per hour (43 million km/h) —making it the fastest star in the Milky Way ever clocked by astronomers, according to the new research. Its speed will allow it to escape the gravitational pull of the galaxy, and eventually make its way into intergalactic space. A NASA animation shows the hypervelocity star’s ejection after a star explosion, kicking off the rogue flight across the Milky Way.

    Temp 1
    An astrophysicist-artist’s conception of a hypervelocity star speeding away from the visible part of a spiral galaxy like our Milky Way. Hypervelocity star 708 is now the fastest-recorded star on its way out of the galaxy, and its origin story is highly unique. Credit: Ben Bromley, University of Utah

    Most other stars moving fast enough to get out of the galaxy are thought to be ejected by the monster black hole at the galactic center, the researchers say. US 708 is the first star with a different origin story, and the new research suggests its life has been strange and chaotic

    Outta Here!

    Our sun and most of the millions of stars in the Milky Way collectively orbit the center of the galaxy at a mild pace: Our sun travels about 125 miles per second, or 450,000 miles per hour.

    But there is a class of so-called hypervelocity stars, or HVSs, that are moving with speeds high enough to escape the gravitational pull of the galaxy.

    Thus far, the fastest of these hypervelocity stars have been clocked at about 2 million miles per hour. But US 708 is moving at more than 26 million miles per hour.

    “It’s significantly faster,” said Stephan Geier, a postdoctoral researcher at the European Southern Observatory and co-author on the new research.

    Geier and some colleagues first identified US 708 in 2005. In the new work, he and his co-authors were able to measure the speed of the star by using both current and archival data, and watching its motion change over a total of about 70 years.

    The monster black hole at the center of the Milky Way has the gravitational muscle to fling a star on a one-way-track out of the neighborhood, and many other hypervelocity stars are thought to originate from there. But US 708 didn’t start its journey near the galactic center, the new research shows.

    Based on additional clues, the scientists say it was probably orbiting another star when its path changed. US 708 and its partner star were likely orbiting each other very quickly, with a very small distance between them. The neighbor star exploded into a supernova and was completely destroyed. US 708 was suddenly without a gravitational tether to keep it in the same place, and all that rotational speed and energy then abruptly started moving in a straight line.

    “It’s like if you are riding a swing carousel, where you are connected with a chain, and you cut the chain — then you fly away from the carousel,” Geier said. “In this case the carousel explodes.”

    An uncommon life for a star

    The researchers can’t look back in time to see what happened to US 708 before it was set on its current course. But the clues they need are in the star’s physical characteristics and current behavior.

    Speed isn’t the only thing that sets US 708 apart from other hypervelocity stars. Before 2014, all detected HVSs were main sequence stars, similar to our sun. Early that year, a group of much larger hypervelocity stars was discovered (those stars also appear to have originated away from the galactic center). But US 708 is not main sequence, and it is not large; it’s what’s known as a hot subdwarf.

    As their name suggests, hot subdwarfs are small but have very high temperatures suggesting they were once much more massive. US 708 is currently about half the mass of our sun, but the researchers say it was likely a red giant earlier in its lifetime, with a mass two to three times that of our sun. The red giant’s outer layers of hydrogen were probably siphoned off by another nearby star, leaving behind a smaller subdwarf star made mostly of helium.

    This cannibalizing neighbor star was most likely a white dwarf: a collapsed star that is no longer burning fuel. After it ate the outer layers of hydrogen from US 708, it then began sucking helium away from US 708, which is what eventually led to its demise.

    As the white dwarf gobbled up more of this material, steadily creating a thick, hot layer on its surface, the helium ignited. Theories suggest that this buildup and ignition of helium then kick-starts the burning of carbon inside the star, which can then trigger the destruction of the entire star, as in a Type 1a supernova explosion.

    “The white dwarf was completely destroyed,” Geier said.

    Once again, the removal of the white dwarf set US 708 on a path out of the galaxy. The explosion itself most likely contributed very little energy to the star as it left the system, he said.

    “It’s probably one of the most dramatic life stories of a star,” Geier said. “The star went through a lot.”

    The researchers can’t say for sure if US 708 came from a region where a Type 1a supernova went off. The remnants of such an event would be long gone, Geier said. But the physical characteristics of the star led them to this conclusion: the fact that US 708 is a hot subdwarf made mostly of helium, and the fact that it is rotating very rapidly (this would be a product of its close orbit with the white dwarf).

    Geier and his colleagues say studying more stars like US 708 could provide information about how Type 1a supernovas form. Scientists use these bright points of light to measure large distances in the universe, so understanding them better can influence many areas of astronomy.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 9:04 am on July 16, 2015 Permalink | Reply
    Tags: , , , space.com   

    From space.com: “Ingredients for Earth-Like Planets Are Found All Around the Milky Way” 

    space-dot-com logo

    SPACE.com

    July 10, 2015
    Elizabeth Howell

    The building blocks to create another Earth are found at solar systems across our Milky Way galaxy, a new study reveals.

    By saying that carbon, oxygen, magnesium and silicon are in rocky planets everywhere, this new study contradicts previous research that’s said only some rocky planets have this recipe. Previously, scientists said there were three kinds of rocky planets: those similar to Earth, those that had more carbon, and some that had a lot more silicon than magnesium.

    “The ratio of elements on Earth has led to the chemical conditions ‘just right’ for life,” said lead researcher Brad Gibson, an astrophysicist at the University of Hull in the United Kingdom. “Too much magnesium or too little silicon, and your planet ends up having the wrong balance between minerals to form the type of rocks that make up the Earth’s crust,” Gibson added. “Too much carbon, and your rocky planet might turn out to be more like the graphite in your pencil than the surface of a planet like the Earth.”

    The new results come from a simulation of how the Milky Way formed. While Gibson said he was worried at first that the model was wrong, he added that it predicted different parts of our galaxy correctly — such as how frequently stars formed and died.


    Download is available at video

    The researchers also examined observations and found uncertainties concerning how many rocky-planet systems had recipes similar to Earth’s. “Removing these [uncertainties],” Gibson said, “observations agreed with our predictions that the same elemental building blocks are found in every exoplanet system, wherever it is in the galaxy.”

    Specifically, the uncertainties happened because observations tend to come from large planets that are orbiting bright stars, which are easier to see from Earth. This creates uncertainties of 10 percent to 20 percent, the researchers said.

    Also, oxygen and nickel spectra are hard to see from a distance, which adds to the uncertainty. Newer techniques will make these observations more accurate, the researchers added.

    The research was presented Wednesday (July 8) at the National Astronomy Meeting in Llandudno, Wales.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 4:32 pm on July 12, 2015 Permalink | Reply
    Tags: , , , space.com   

    From Space.com: “Ingredients for Earth-Like Planets Are Found All Around the Milky Way” 

    space-dot-com logo

    SPACE.com

    July 10, 2015
    Elizabeth Howell

    1
    An artist’s depiction of gas and dust creating planets around a young star. Credit: NASA/JPL-Caltech

    The building blocks to create another Earth are found at solar systems across our Milky Way galaxy, a new study reveals.

    By saying that carbon, oxygen, magnesium and silicon are in rocky planets everywhere, this new study contradicts previous research that’s said only some rocky planets have this recipe. Previously, scientists said there were three kinds of rocky planets: those similar to Earth, those that had more carbon, and some that had a lot more silicon than magnesium.

    “The ratio of elements on Earth has led to the chemical conditions ‘just right’ for life,” said lead researcher Brad Gibson, an astrophysicist at the University of Hull in the United Kingdom.

    “Too much magnesium or too little silicon, and your planet ends up having the wrong balance between minerals to form the type of rocks that make up the Earth’s crust,” Gibson added. “Too much carbon, and your rocky planet might turn out to be more like the graphite in your pencil than the surface of a planet like the Earth.”

    The new results come from a simulation of how the Milky Way formed. While Gibson said he was worried at first that the model was wrong, he added that it predicted different parts of our galaxy correctly — such as how frequently stars formed and died.

    The researchers also examined observations and found uncertainties concerning how many rocky-planet systems had recipes similar to Earth’s. “Removing these [uncertainties],” Gibson said, “observations agreed with our predictions that the same elemental building blocks are found in every exoplanet system, wherever it is in the galaxy.”

    Specifically, the uncertainties happened because observations tend to come from large planets that are orbiting bright stars, which are easier to see from Earth. This creates uncertainties of 10 percent to 20 percent, the researchers said.

    Also, oxygen and nickel spectra are hard to see from a distance, which adds to the uncertainty. Newer techniques will make these observations more accurate, the researchers added.

    The research was presented Wednesday (July 8) at the National Astronomy Meeting in Llandudno, Wales.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 6:38 am on June 20, 2015 Permalink | Reply
    Tags: , , space.com,   

    From Space.com: “What is a Wormhole?” 

    space-dot-com logo

    SPACE.com

    1
    A model of ‘folded’ space-time illustrates how a wormhole bridge might form with at least two mouths that are connected to a single throat or tube. Credit: edobric | Shutterstock

    A wormhole is a theoretical passage through space-time that could create shortcuts for long journeys across the universe. Wormholes are predicted by the theory of general relativity. But be wary: wormholes bring with them the dangers of sudden collapse, high radiation and dangerous contact with exotic matter.

    Wormhole theory

    In 1935, physicists Albert Einstein and Nathan Rosen used the theory of general relativity to propose the existence of “bridges” through space-time. These paths, called Einstein-Rosen bridges or wormholes, connect two different points in space-time, theoretically creating a shortcut that could reduce travel time and distance.

    Wormholes contain two mouths, with a throat connecting the two. The mouths would most likely be spheroidal. The throat might be a straight stretch, but it could also wind around, taking a longer path than a more conventional route might require.

    Einstein’s theory of general relativity mathematically predicts the existence of wormholes, but none have been discovered to date. A negative mass wormhole might be spotted by the way its gravity affects light that passes by.

    Certain solutions of general relativity allow for the existence of wormholes where the mouth of each is a black hole. However, a naturally occurring black hole, formed by the collapse of a dying star, does not by itself create a wormhole.

    Exotic matter, which should not be confused with dark matter or antimatter, contains negative energy density and a large negative pressure. Such matter has only been seen in the behavior of certain vacuum states as part of quantum field theory.

    If a wormhole contained sufficient exotic matter, whether naturally occurring or artificially added, it could theoretically be used as a method of sending information or travelers through space.

    Wormholes may not only connect two separate regions within the universe, they could also connect two different universes. Similarly, some scientists have conjectured that if one mouth of a wormhole is moved in a specific manner, it could allow for time travel. However, British cosmologist Stephen Hawking has argued that such use is not possible. [Weird Science: Wormholes Make the Best Time Machines]

    “A wormhole is not really a means of going back in time, it’s a short cut, so that something that was far away is much closer,” NASA’s Eric Christian wrote.

    Although adding exotic matter to a wormhole might stabilize it to the point that human passengers could travel safely through it, there is still the possibility that the addition of “regular” matter would be sufficient to destabilize the portal.

    Today’s technology is insufficient to enlarge or stabilize wormholes, even if they could be found. However, scientists continue to explore the concept as a method of space travel with the hope that technology will eventually be able to utilize them.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 8:57 am on March 26, 2015 Permalink | Reply
    Tags: , , , space.com   

    From Space.com: “The Strangest Black Holes in the Universe” 2013 But Interesting 

    space-dot-com logo

    SPACE.com

    July 08, 2013
    Charles Q. Choi

    Black holes are gigantic cosmic monsters, exotic objects whose gravity is so strong that not even light can escape their clutches.

    The Biggest Black Holes
    1
    Credit: Pete Marenfeld

    Nearly all galaxies are thought to harbor at their cores supermassive black holes millions to billions of times the mass of our sun. Scientists recently discovered the largest black holes known in two nearby galaxies.

    One of these galaxies, known as NGC 3842 — the brightest galaxy in the Leo cluster nearly 320 million light years away — has a central black hole containing 9.7 billion solar masses. The other, NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass.

    3
    NGC 4889
    Credit: Sloan Digital Sky Survey, Spitzer Space Telescope
    Sloan Digital Sky Survey Telescope
    SDSS telescope

    NASA Spitzer Telescope
    NASA/Spitzer

    The Smallest Black Hole
    2
    Credit: NASA/Goddard Space Flight Center/CI Lab

    The gravitational range, or “event horizon,” of these black holes is about five times the distance from the sun to Pluto. For comparison, these blaVck holes are 2,500 times as massive as the black hole at the center of the Milky Way galaxy, whose event horizon is one-fifth the orbit of Mercury.

    The smallest black hole discovered to date may be less than three times the mass of our sun. This would put this little monster, officially called IGR J17091-3624, near the theoretical minimum limit needed for a black hole to be stable. As tiny as this black hole may be, it looks fierce, capable of 20 million mph winds (32 million kph) — the fastest yet observed from a stellar-mass black hole by nearly 10 times.

    Cannibalistic Black Holes
    3
    Credit: X-ray: NASA/CXC/SAO/G.Fabbiano et al; Optical: NASA/STScI

    NASA Chandra schematic
    NASA/Chandra

    NASA Hubble Telescope
    NASA/ESA Hubble [not in notes but in credit]

    Black holes devour anything unlucky enough to drift too close, including other black holes. Scientists recently detected the monstrous black hole at the heart of one galaxy getting consumed by a still larger black hole in another.

    The discovery is the first of its kind. Astronomers had witnessed the final stages of the merging of galaxies of equal mass — so-called major mergers — but minor mergers between galaxies and smaller companions had long eluded researchers.

    Using NASA’s Chandra X-ray Observatory, investigators detected two black holes at the center of a galaxy dubbed NGC3393, with one black hole about 30 million times the mass of the sun and the other at least 1 million times the mass of the sun, separated from each other by only about 490 light-years.

    Bullet-shooting Black Hole
    4
    Credit: Greg Sivakoff/University of Alberta

    Black holes are known for sucking in matter, but researchers find they can shoot it out as well. Observations of a black hole called H1743-322, which harbors five to 10 times the mass of the sun and is located about 28,000 light-years from Earth, revealed it apparently pulled matter off a companion star, then spat some of it back out as gigantic “bullets” of gas moving at nearly a quarter the speed of light.

    The Oldest Known Black Hole
    5
    Credit: ESO/M. Kornmesser

    The oldest black hole found yet, officially known as ULAS J1120+0641, was born about 770 million years after the Big Bang that created our universe. (Scientists think the Big Bang occurred about 13.7 billion years ago.)

    The ancient age of this black hole actually poses some problems for astronomers. This brilliant enigma appears to be 2 billion times the mass of the sun. How black holes became so massive so soon after the Big Bang is difficult to explain.

    The Brightest Black Hole
    6
    Credit: HST

    Although the gravitational pulls of black holes are so strong that even light cannot escape, they also make up the heart of quasars, the most luminous, most powerful and most energetic objects in the universe.

    As supermassive black holes at the centers of galaxies suck in surrounding gas and dust, they can spew out huge amounts of energy. The brightest quasar we see in the visible range is 3C 273, which lies about 3 billion light-years away.

    Rogue Black Holes
    7
    Credit: David A. Aguilar (CfA)

    When galaxies collide, black holes can get kicked away from the site of the crash to roam freely through space. The first known such rogue black hole, SDSSJ0927+2943, may be approximately 600 million times the mass of the sun and hurtle through space at a whopping 5.9 million mph (9.5 million kph). Hundreds of rogue black holes might wander the Milky Way.

    Middleweight Black Holes
    8
    Credit: NASA

    Scientists have long thought that black holes come in three sizes — essentially small, medium and large. Relatively small black holes holding the mass of a few suns are common, while supermassive black holes millions to billions of solar masses are thought to lurk at the heart of nearly every galaxy. One more massive than four million suns, for example, is thought to hide in the center of the Milky Way.

    However, middle-weight black holes had eluded astronomers for years. Scientists recently discovered an intermediate-mass black hole, called HLX-1 (Hyper-Luminous X-ray source 1), approximately 290 million light-years from Earth, which appears to be about 20,000 solar masses in size.

    Medium-size black holes are thought to be the building blocks of supermassive black holes, so understanding more about them can shed light on how these monsters and the galaxies that surround them evolved.

    Fastest-spinning Black Hole
    9
    Credit: NASA / NASA / CXC / M.Weiss

    Black holes can whirl the fabric of space around themselves at extraordinary speeds. One black hole called GRS 1915+105, in the constellation Aquila (The Eagle) about 35,000 light-years from Earth, is spinning more than 950 times per second.

    An item placed on the edge of the black hole’s event horizon — the edge past which nothing can escape — would spin around it at a speed of more than 333 million mph (536 million kph), or about half the speed of light.

    Tabletop Black Holes
    10
    Credit: Chris Kuklewicz

    Black holes are thankfully quite far away from Earth, but this distance makes it difficult to gather clues that could help solve the many mysteries that surround them. However, researchers are now recreating the enigmatic properties of black holes on tabletops.

    For instance, black holes possess gravitational pulls so powerful that nothing, including light, can escape after falling past a border known as the event horizon. Scientists have created an artificial event horizon in the lab using fiber optics. They have also recreated the so-called Hawking radiation thought to escape from black holes.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 10:58 am on March 15, 2015 Permalink | Reply
    Tags: , , , , space.com   

    From Space.com: “New Horizons: Exploring Pluto and Beyond” 

    space-dot-com logo

    SPACE.com

    January 27, 2015
    Elizabeth Howell

    NASA New Horizons spacecraft II
    NASA/New Horizons spacecraft

    New Horizons is a NASA spacecraft on its way to the dwarf planet Pluto. It scooted by Jupiter in 2007, and will pass by Pluto in July 2015 before possibly heading farther into the Kuiper Belt — a massive zone of icy bodies beyond Neptune.

    2
    Known objects in the Kuiper belt beyond the orbit of Neptune (scale in AU; epoch as of January 2015).

    Investigators with the Hubble Space Telescope have identified a few targets for the spacecraft after it zooms by Pluto and its moons, but the mission extension depends on how well New Horizons is performing at that time and if it can receive approval in NASA’s budget.

    NASA Hubble Telescope
    NASA/ESA HUbble

    When the spacecraft reaches Pluto, it will be only the fifth one to head so far away from Earth (the other ones being Pioneer 10 and Pioneer 11, and Voyager 1 and Voyager 2, which are either in the outer solar system or in the case of Voyager 1, interstellar space.)

    NASA Pioneer 10
    Pioneer 10

    NASA Pioneer 11
    Pioneer 11

    NASA Voyager 1
    Voyager 1

    NASA Voyager 2
    Voyager 2

    Pluto’s distance — about 3 billion miles (5 billion kilometers) from Earth — presented power challenges for New Horizon’s designers, since the sun’s rays are too weak to generate power. There will also be long communications delays for those staying in touch with the 1,054-pound spacecraft; at Pluto, it will take 4.5 hours for a one-way message to get there from Earth.

    Further, our understanding of the Pluto system keeps changing. The planet was discovered in 1930 by astronomer Clyde Tombaugh at the Lowell Observatory.

    Lowell Observatory
    Lowell Observatory

    Since then, we’ve discovered new moons — which can also be seen as dangerous obstacles for a spacecraft, if not accounted for. And in 2006 — shortly after New Horizons launched — astronomers voted to demote Pluto from its planetary status. New Horizons carries some of Tombaugh’s ashes.

    Design challenges for long missions

    Spacecraft typically have a set design lifetime, similar to warranties on electronics or cars. Over time, solar particles, cosmic rays and other phenomena can degrade the surface of the spacecraft or mess up the electronics. This makes long missions such as New Horizons especially challenging.

    “You’ve got to remember that it takes 9.5 years to even get to where we want to take the mission,” said Glen Fountain, the New Horizons mission project manager from Johns Hopkins University Applied Physics Laboratory, in a 2006 interview with NASA.

    “So we need a highly reliable system,” he said. “So, we have built into the electronics nearly two of everything. We are redundant. We have two guidance control processors, computers. We have two command and data handling processors. We have two solid-state recorders. Even if there is a failure, you can switch from one to the other.”

    Another question, Fountain acknowledged, was how to handle power when the sun is too weak to provide solar power. New Horizons carries nuclear power (more precisely, a radioisotope thermoelectric generator) on board to solve this problem.

    Mission Control kept the spacecraft in deep hibernation after a quick pass by Jupiter in February 2007. New Horizons underwent periodic wakeups until a last emerging from hibernation for good in December 2014, which will last through the “Pluto encounter” of 2015.

    NASA did a detailed systems check of the spacecraft once a year to make sure it’s working properly and to, if necessary, make adjustments to its path to Pluto. The spacecraft also ferried a basic signal back to Earth once a week.

    Zipping by Jupiter

    New Horizons launched Jan. 19, 2006, on an Atlas V rocket from Cape Canaveral Air Force Station in Florida. A power outage and high winds delayed two previous launch attempts, but New Horizons made it safely into space on the third try.

    The spacecraft’s first destination was Jupiter, in February and March 2007. New Horizons passed by less than 1.4 million miles (2.4 million km) of the solar system’s largest planet, making it the first spacecraft to swing by since the Galileo probe finished its mission at Jupiter in 2003.

    NASA Galileo
    Galileo

    Among New Horizons’ first pictures were some of Io, Jupiter’s volcanic moon. The spacecraft captured the clearest pictures ever of the Tvashtar volcano on Io, showing volcanic fallout that was bigger than the state of Texas.

    Additionally, the spacecraft flew through a stream of charged particles swirling behind Jupiter. It found large bubbles of charged particles, or plasma, and also revealed variations in the stream.

    At the time, astronomers said the observations could help with understanding the environment around “hot Jupiter” planets found at other stars.

    Plans for Pluto

    One of the principal aims of New Horizons is to figure out the origins of Pluto and its companion Charon, a moon that is more than half Pluto’s size. At the time, Pluto and Charon were considered a double planet (although the definition of Pluto changed, as will be explained below.)

    NASA believed Charon formed when Pluto hit another big object long ago, creating debris that circled around Pluto and eventually formed Charon. It’s a similar theory to how Earth’s moon formed, so the scientists hoped to understand the creation of our moon better by looking at Charon’s origins.

    Scientists are also eager to learn about the visual differences between Charon and Pluto. From Hubble observations, researchers deduced Pluto is far more reflective than Charon, and that Pluto has an atmosphere while Charon does not.

    NASA further speculated that Pluto might even have volcanic activity, because the Voyager 2 spacecraft spotted possible volcanoes (to researchers’ surprise) on Triton, a moon of Neptune that is of a similar size and composition.

    New Horizons crossed Neptune’s orbit in August 2014, and in September, the spacecraft team released pictures that the machine took of a small moon called Hydra that summer. The goal was not only to take the pictures, but to do a simulated “satellite search” — it’s possible there are other moons of Pluto that are just waiting to be discovered, when the spacecraft gets closer.

    The spacecraft emerged from hibernation again in December 2014, representing the first of a series of milestones as New Horizons approaches Pluto. “Technically, this was routine, since the wake-up was a procedure that we’d done many times before,” said Glen Fountain, New Horizons project manager at the Johns Hopkins Applied Physics Laboratory, in a statement. “Symbolically, however, this is a big deal. It means the start of our pre-encounter operations.”

    Pluto’s planetary status changes

    Ten years can be a long time in planetary science, and that is particularly true of Pluto. Since New Horizons left our planet in 2006, we’ve discovered another moon nearby Pluto. Planners have made course corrections to keep the spacecraft away from Pluto’s moons.

    Further, Pluto was demoted from its position as the ninth planet in our solar system. In August 2006, members of the International Astronomical Union (IAU) — the global body that governs astronomy names and other matters — met in a general assembly to decide on the definition of a planet.

    This vote was called in response to the recent discoveries of large bodies in the Kuiper Belt, an area beyond Neptune believed to contain trillions of objects.

    On Aug. 24, 2006, IAU representatives determined three features all planets must possess:

    They must orbit the sun (and not another body, as a moon orbits a planet).
    They must have enough mass to form a round shape.
    They must be large enough to clean out bits of rock and other matter in the area around their orbits.

    Pluto didn’t meet all the classifications, and was reclassified as a dwarf planet.

    The decision drew fire from Alan Stern, the principal investigator of the New Horizons mission. “I’m embarrassed for astronomy. Less than 5 percent of the world’s astronomers voted,” he said in a 2006 interview with Space.com. “This definition stinks, for technical reasons.”

    The decision is still controversial, years later. Little is known about Pluto because it is so far away from Earth, but we have been able to increase our understanding of it by peering at the planet with the Hubble Space Telescope and other observatories. More fuel may be added to the debate as NASA’s Dawn spacecraft gets close-up to Ceres this year, one of the largest members of our solar system’s asteroid belt.

    NASA Dawn Spacescraft
    NASA/Dawn

    3
    An overhead view of the New Horizons spacecraft’s path across Uranus’ orbit.
    Credit: NASA, JHU/APL

    Post-Pluto

    It is expected that New Horizon’s arrival at Pluto will give us more data about its surface, its moons and its environment, which can better refine our knowledge of the dwarf planet and its system.

    Over the northern hemisphere summer of 2014, investigators used the Hubble Space Telescope to see if there were any Kuiper Belt objects within reach of New Horizons after it concludes its Pluto mission. Scientists identified three candidates, with each of them at least 1 billion miles (1.6 billion kilometers) beyond the dwarf planet.

    The team plans to make a pitch to NASA for extended operations in 2016, to take a closer look at one of these worlds. Meanwhile, even after the mission ends, a group of scientists, artists, engineers and more are proposing placing a sort of message from Earth on the free hard drive space on the New Horizons spacecraft.

    “When New Horizons gets past Pluto, [and] has done all its data and is going on the slow boat to the heliopause [the boundary between the solar system and interstellar space], then it might be possible to just reprogram about 100 megabytes of its memory and upload a new sights and sounds of Earth that are not created by a small group of scientists but, in fact, are globally crowdsourced,” said Jill Tarter, who is the co-founder of the SETI (Search for Extraterrestrial Intelligence) Institute, in 2013.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 3:27 am on March 12, 2015 Permalink | Reply
    Tags: , , , space.com   

    From Space.com: “Eagle Nebula (M16): Hubble Images & Pillars of Creation” 2012 

    space-dot-com logo

    SPACE.com

    July 02, 2012
    Nola Taylor Redd

    1
    This classic image of the Pillars of Creation inside of the Eagle Nebula reveals a stellar nursery where new stars may be hatched.
    Credit: NASA, ESA, STScI, J. Hester and P. Scowen (Arizona State University)

    NASA Hubble Telescope
    Hubble

    In 1995, the world was astounded by the beautiful Hubble Space Telescope images of the Eagle Nebula a cloud of interstellar gas and dust 7,000 light-years from Earth. Let’s take a look at this intriguing region.

    What is the Eagle Nebula?

    2
    Overview of some famous sights in the Eagle Nebula
    HST 24 August 2008

    Also known as M16, the Eagle Nebula is a 5.5 million-year-old cloud of molecular hydrogen gas and dust stretching approximately 70 light years by 55 light years. Inside the nebula, gravity pulls clouds of gas together to collapse inward. If enough gas is present, nuclear fusion is ignited in the center, and the compact cloud becomes a shining star. The Eagle Nebula is thought to have several star-forming regions within it.

    The gas and dust that ultimately collapsed into the sun four billion years ago likely resided in a structure similar to the Eagle Nebula.

    2
    A tower of cold gas and dust rises from the Eagle Nebula.
    Credit: NASA, ESA, and The Hubble Heritage Team STScI/AURA)

    Where is the Eagle Nebula?

    The Eagle Nebula lies 6,500 light-years away in the inner spiral arm of the Milky Way next to our own, the Sagittarius or Sagittarius-Carina Arm. When viewing the sky, the stellar nursery is found within the constellation of Serpens, the Serpent.

    The nebula is viewable with the low-powered telescopes readily available to amateur astronomers, or with a pair of binoculars. With such equipment, observers can see approximately twenty stars clearly, surrounded by gas, dust, and the light of other, dimmer stars. In good conditions, the three pillars may also be seen.

    What are the Pillars of Creation?

    One of the best-known pictures of the Eagle Nebula is the Hubble Space Telescope image taken in 1995, highlighting the “Pillars of Creation.” The three columns contain the materials for building new stars, and stretch four light-years out into space. Newborn stars outside of the famous Hubble image are responsible for sculpting the pillars, using ultraviolet light to burn away some of the gas within the clouds.

    3

    In 2010, images of the pillars taken by NASA’s Chandra X-ray Observatory peered inside the pillars to reveal only a handful of x-ray sources. Because new stars are supposed to be a hot bed of x-ray activity, scientists speculated that the star-forming days of the pillars were coming to an end. [VIDEO: Inside the Pillars of Creation]

    Similarly, research from 2007 suggested that a stellar supernova six thousand years ago could have already blown the pillars out of formation and into space. Because light takes time to travel, it may be another thousand years before we can see their demise.

    4
    Chandra’s X-ray Observatory reveals x-ray images in the Eagle Nebula, although few are visible within the Pillars of Creation
    Credit: X-ray: NASA/CXC/U.Colorado/Linsky et al.; Optical: NASA/ESA/STScI/ASU/J.Hester & P.Scowen

    NASA Chandra Telescope
    Chandra

    What are EGGs?

    Evaporating gaseous globules, or EGGs, are dense pockets of gas that lie at the top of the columns. Some EGGs appear as tiny bumps in the surface, while others have been completely uncovered or cut off completely from the pillars.

    Although some EGGs will collapse down into new stars, others lack sufficient gas to create a new stellar candidate.

    The EGGs are about a hundred times the Earth’s distance to the sun, so the solar system would fit comfortably inside most of them. They last ten thousand to twenty thousand years.

    Discovery of the Eagle Nebula

    When Swiss astronomer Philippe Loys de Chéseaux discovered the Eagle Nebula in the mid-eighteenth century, he only described the cluster of stars surrounding it. Charles Messier independently rediscovered it in 1764 as part of his catalog, dubbing it M16.

    The first image of the nebula appears to have been made by American astronomer Edward Barnard, in 1895.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 454 other followers

%d bloggers like this: