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  • richardmitnick 6:45 am on April 29, 2016 Permalink | Reply
    Tags: , , Comets, Earth Has Mystery Gas Delivered from Space,   

    From SA: “Earth Has Mystery Gas Delivered from Space” 

    Scientific American

    Scientific American

    April 28, 2016
    Anthony King, ChemistryWorld

    1
    Credit: Wikimedia Commons/NASA/JPL-Caltech

    Xenon from deep within the Earth’s mantle has shone a light on the planet’s formation and early evolution. The isotopic signature of this earthly xenon has been shown to resemble that of primitive meteorites and differs markedly from the profile of the gas found in the atmosphere, which is mysteriously missing most of its xenon.

    The origin of Earth’s volatile elements such as water, carbon and nitrogen remains a puzzle. It is difficult to determine if these elements originated from solar gas after the solar system formed or were delivered by asteroids or comets.

    A new study, which sampled xenon from carbon dioxide-rich mineral spring gas from the volcanic Eifel province in Germany, points to an asteroidal origin for part of the volatile elements trapped in Earth’s mantle—planetary bodies whose remnants now lie between Mars and Jupiter. The mysterious xenon in the atmosphere came from elsewhere, possibly comets.

    ‘We conclude that this [mantle] component was contributed by asteroids when the proto-Earth was still building up,’ notes senior author Bernard Marty at the University of Lorraine, France. ‘The ancestor atmosphere xenon was contributed later on at the Earth’s surface, by late bombardments, and never mixed up with mantle xenon.’ This late bombardment occurred around 800 million years after Earth’s formation and might have involved cometary bodies. The isotopic signature of xenon on comets is unknown, however.

    The extraterrestrial chondritic xenon found in the mantle has been isolated for 4.45 billion years. It also proves that volcanism in Eifel relates to upwelling from the deep mantle, likely to be over 700 km deep.

    ‘It’s a small step forward to show that mantle xenon came from meteorites, but the big step forward is showing that this component is not related to the atmosphere,’ says Christopher Ballentine, a geochemist at the University of Oxford, UK, who was not involved with this work.

    Atmospheric xenon’s origin was not just from outgassing of the mantle and is more complex, Ballentine explains. ‘Nobody has measured xenon composition in comets yet, so maybe that is the source,’ he adds. Around 90% of the xenon expected to be in Earth’s atmosphere is missing, with various theories posited. The enigma of the ‘missing xenon’ and where it went is one of the big unsolved puzzles in geochemistry.

    ‘Understanding xenon really is a lynchpin for understanding the early formation of volatiles. And resolving how volatiles arrived at the planet tells us something fundamental about the way in which the planets formed,’ Ballentine says.

    See the full article here .

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  • richardmitnick 12:12 pm on December 22, 2015 Permalink | Reply
    Tags: , , Comets,   

    From RAS: “Giant comets could pose danger to life on Earth” 

    Royal Astronomical Society

    Royal Astronomical Society

    22 December 2015
    Media contacts
    Robert Massey
    Royal Astronomical Society
    Tel: +44 (0)7802 877 699
    rm@ras.org.uk

    Diana Blamires
    University of Buckingham
    diana.blamires@buckingham.ac.uk

    Science contacts
    Dr David Asher
    dja@arm.ac.uk
    Professor Mark Bailey
    meb@arm.ac.uk
    Armagh Observatory
    Northern Ireland
    Tel: +44 (0)28 3752 2928
    http://star.arm.ac.uk

    Professor Bill Napier
    University of Buckingham
    Tel (Ireland): +353 87361 8376
    bill_napier121@hotmail.com

    Professor Duncan Steel
    University of Buckingham
    Tel (New Zealand): +64 4889 0241
    tma1@duncansteel.com

    1
    Because they are so distant from the Earth, Centaurs appear as pinpricks of light in even the largest telescopes. Saturn’s 200-km moon Phoebe, depicted in this image, seems likely to be a Centaur that was captured by that planet’s gravity at some time in the past. Until spacecraft are sent to visit other Centaurs, our best idea of what they look like comes from images like this one, obtained by the Cassini space probe orbiting Saturn. NASA’s New Horizons spacecraft, having flown past Pluto six months ago, has been targeted to conduct an approach to a 45-km wide trans-Neptunian object at the end of 2018. Credit: NASA/JPL-Caltech/Space Science Institute.

    NASA Cassini Spacecraft
    NASA/Cassini

    2
    The outer solar system as we now recognise it. At the centre of the map is the Sun, and close to it the tiny orbits of the terrestrial planets (Mercury, Venus, Earth and Mars). Moving outwards and shown in bright blue are the near-circular paths of the giant planets: Jupiter, Saturn, Uranus and Neptune. The orbit of Pluto is shown in white. Staying perpetually beyond Neptune are the trans-Neptunian objects (TNOs), in yellow: seventeen TNO orbits are shown here, with the total discovered population at present being over 1,500. Shown in red are the orbits of 22 Centaurs (out of about 400 known objects), and these are essentially giant comets (most are 50-100 km in size, but some are several hundred km in diameter). Because the Centaurs cross the paths of the major planets, their orbits are unstable: some will eventually be ejected from the solar system, but others will be thrown onto trajectories bringing them inwards, therefore posing a danger to civilisation and life on Earth. Credit: Duncan Steel.

    A team of astronomers from Armagh Observatory and the University of Buckingham report that the discovery of hundreds of giant comets in the outer planetary system over the last two decades means that these objects pose a much greater hazard to life than asteroids. The team, made up of Professors Bill Napier and Duncan Steel of the University of Buckingham, Professor Mark Bailey of Armagh Observatory, and Dr David Asher, also at Armagh, publish their review of recent research in the December issue of Astronomy & Geophysics (A&G), the journal of the Royal Astronomical Society.

    The giant comets, termed centaurs, move on unstable orbits crossing the paths of the massive outer planets Jupiter, Saturn, Uranus and Neptune. The planetary gravitational fields can occasionally deflect these objects in towards the Earth.

    Centaurs are typically 50 to 100 kilometres across, or larger, and a single such body contains more mass than the entire population of Earth-crossing asteroids found to date. Calculations of the rate at which centaurs enter the inner solar system indicate that one will be deflected onto a path crossing the Earth’s orbit about once every 40,000 to 100,000 years. Whilst in near-Earth space they are expected to disintegrate into dust and larger fragments, flooding the inner solar system with cometary debris and making impacts on our planet inevitable.

    Known severe upsets of the terrestrial environment and interruptions in the progress of ancient civilisations, together with our growing knowledge of interplanetary matter in near-Earth space, indicate the arrival of a centaur around 30,000 years ago. This giant comet would have strewn the inner planetary system with debris ranging in size from dust all the way up to lumps several kilometres across.

    Specific episodes of environmental upheaval around 10,800 BCE and 2,300 BCE, identified by geologists and palaeontologists, are also consistent with this new understanding of cometary populations. Some of the greatest mass extinctions in the distant past, for example the death of the dinosaurs 65 million years ago, may similarly be associated with this giant comet hypothesis.

    Professor Napier comments: “In the last three decades we have invested a lot of effort in tracking and analysing the risk of a collision between the Earth and an asteroid. Our work suggests we need to look beyond our immediate neighbourhood too, and look out beyond the orbit of Jupiter to find centaurs. If we are right, then these distant comets could be a serious hazard, and it’s time to understand them better.”

    The researchers have also uncovered evidence from disparate fields of science in support of their model. For example, the ages of the sub-millimetre craters identified in lunar rocks returned in the Apollo program are almost all younger than 30,000 years, indicating a vast enhancement in the amount of dust in the inner Solar system since then.

    See the full article here .

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  • richardmitnick 4:17 pm on December 10, 2015 Permalink | Reply
    Tags: , , Comets, Molecular Oxygen,   

    From phys.org: “Could molecular oxygen be common on comets?” 

    physdotorg
    phys.org

    December 10, 2015
    Tomasz Nowakowski

    Temp 1
    An image of Halley’s Comet taken in 1986. Credit: NASA

    A team of researchers, encouraged by the latest discovery of ESA’s Rosetta spacecraft of molecular oxygen (O2) on the comet 67P/Churyumov-Gerasimenko, are going over comet 1P/Halley (known as Halley’s Comet) with a fine-tooth comb, searching for the traces of this essential molecule.

    ESA Rosetta spacecraft
    ESA/Rosetta

    The new study, led by Martin Rubin of the University of Bern, Switzerland, shows that molecular oxygen is also present on 1P/Halley and therefore might be common on other comets.

    The scientists used the data from the Neutral Mass Spectrometer (NMS) instrument aboard ESA’s Giotto probe, which passed 1P/Halley in 1986.

    ESA Giotto
    ESA/Giotto

    They found that O2 is the third most abundant species on this celestial body. The results were published on Dec. 4 in the Astrophysical Journal Letters.

    Giotto approached Halley’s nucleus at a distance of 596 kilometers. Despite being hit by the comet’s small particles, the spacecraft gathered important scientific data during a flyby lasting only few minutes. This close encounter enabled the chemical characterization of the material being ejected from the comet. The results indicated that Halley releases mainly water and carbon monoxide. The data showed also traces of methane, ammonia, other hydrocarbons, as well as iron and sodium. Now, Rubin and his colleagues report abundant amounts of molecular oxygen in the comet’s coma.

    “Our investigation indicates that a production rate of O2 with respect to water is, indeed, compatible with the obtained Halley data, and therefore that O2 might be a rather common and abundant parent species,” the scientist wrote in the paper.

    The first comet on which molecular oxygen was detected is 67P/Churyumov-Gerasimenko, representing Jupiter family comets originating from the Kuiper belt.

    3
    Objects of the Kuiper belt (blue). Plot displays the known positions of objects in the outer Solar System within 60 astronomical units (AU) from the Sun. Epoch as of January 1, 2015.

    The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) found this molecule in October 2015, and since then, the scientists have wondered whether the O2 abundance is peculiar to comet 67P/Churyumov-Gerasimenko or Jupiter family comets in general. The new results hint that the existence of molecular oxygen could also be characteristic for the Oort cloud family of comets that includes Halley.

    4
    This graphic shows the distance from the Oort cloud to the rest of the Solar System and two of the nearest stars measured in astronomical units. The scale is logarithmic, with each specified distance ten times further out than the previous one.

    “We now have an indication for abundant O2 in the comas of two comets, one from the Oort cloud and the other from the Kuiper belt or possibly the scattered disk. This is particularly interesting, as both families of comets are believed to have formed at different locations in our early solar system,” the paper reads.

    The authors of the new study also address what caused the abundance of molecular oxygen on Halley. One possible explanation offered by the scientists is that the O2 has already been formed through irradiation of ices in the molecular cloud phase and the oxygen remained trapped before the comet eventually formed. According to the scientists, the close abundance of oxygen on both comets, despite very different dynamical histories and erosion rates, confirms this hypothesis.

    Comets are essential to improving our understanding of the origins of life. These icy leftovers from the planet-forming process have been preserved at low temperatures since their formation. Thus, the cometary material could provide invaluable hints on how solar system was created.

    Now, when we know that the presence of molecular oxygen is not unique to one comet, a new chapter opens in the search for the ingredients of life on the icy visitors from the outskirts of the solar system. With that in mind, further studies could reveal a vast number of comets rich in oxygen, water and even organic compounds.

    Explore further: Image: Jet activity at the neck of the Rosetta comet

    More information: http://iopscience.iop.org/article/10.1088/2041-8205/815/1/L11/meta;jsessionid=F9A1FE045288EA9414874579F8C6EC06.c3.iopscience.cld.iop.org M. Rubin et al. MOLECULAR OXYGEN IN OORT CLOUD COMET 1P/HALLEY, The Astrophysical Journal (2015). DOI: 10.1088/2041-8205/815/1/L11

    Abstract
    Recently, the ROSINA mass spectrometer suite on board the European Space Agency’s Rosetta spacecraft discovered an abundant amount of molecular oxygen, O2, in the coma of Jupiter family comet 67P/Churyumov–Gerasimenko of O2/H2O = 3.80 ± 0.85%. It could be shown that O2 is indeed a parent species and that the derived abundances point to a primordial origin. Crucial questions are whether the O2 abundance is peculiar to comet 67P/Churyumov–Gerasimenko or Jupiter family comets in general, and also whether Oort cloud comets such as comet 1P/Halley contain similar amounts of molecular oxygen. We investigated mass spectra obtained by the Neutral Mass Spectrometer instrument during the flyby by the European Space Agency’s Giotto probe of comet 1P/Halley. Our investigation indicates that a production rate of O2 of 3.7 ± 1.7% with respect to water is indeed compatible with the obtained Halley data and therefore that O2 might be a rather common and abundant parent species.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 11:22 am on September 2, 2015 Permalink | Reply
    Tags: , Comets,   

    From JPL: “Comet Hitchhiker Would Take Tour of Small Bodies” 

    JPL

    Sep. 1, 2015
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    1
    This artist concept shows Comet Hitchhiker, an idea for traveling between asteroids and comets using a harpoon and tether system. Credits: NASA/JPL-Caltech/Cornelius Dammrich

    Catching a ride from one solar system body to another isn’t easy. You have to figure out how to land your spacecraft safely and then get it on its way to the next destination. The landing part is especially tricky for asteroids and comets, which have low gravitational pull.

    A concept called Comet Hitchhiker, developed at NASA’s Jet Propulsion Laboratory, Pasadena, California, puts forth a new way to get into orbit and land on comets and asteroids, using the kinetic energy — the energy of motion — of these small bodies. Masahiro Ono, the principal investigator based at JPL, had “Hitchhiker’s Guide to the Galaxy” in mind when dreaming up the idea.

    “Hitchhiking a celestial body is not as simple as sticking out your thumb, because it flies at an astronomical speed and it won’t stop to pick you up. Instead of a thumb, our idea is to use a harpoon and a tether,” Ono said. Ono is presenting results about the concept at the American Institute of Aeronautics and Astronautics SPACE conference on September 1.

    A reusable tether system would replace the need for propellant for entering orbit and landing, so running out wouldn’t be an issue, according to the concept design.

    While closely flying by the target, a spacecraft would first cast an extendable tether toward the asteroid or comet and attach itself using a harpoon attached to the tether. Next, the spacecraft would reel out the tether while applying a brake that harvests energy while the spacecraft accelerates.

    This technique is analogous to fishing on Earth. Imagine you’re on a boat on a lake with a fishing pole, and want to catch a big fish. Once the fish bites, you would release more of the line with a moderate tension, rather than holding it tightly. With a long enough line, the boat will eventually catch up with the fish.

    2
    Comet Hitchhiker, shown in this artist rendering, is a concept for orbiting and landing on small bodies. Credits: NASA/JPL-Caltech/Cornelius Dammrich

    Once the spacecraft matches its velocity to the “fish” — the comet or asteroid in this case — it is ready to land by simply reeling in the tether and descending gently. When it’s time to move on to another celestial target, the spacecraft would use the harvested energy to quickly retrieve the tether, which accelerates the spacecraft away from the body.

    “This kind of hitchhiking could be used for multiple targets in the main asteroid belt or the Kuiper Belt, even five to 10 in a single mission,” Ono said.

    Ono and colleagues have been studying whether a harpoon could tolerate an impact of this magnitude, and whether a tether could be created strong enough to support this kind of maneuver. They used supercomputer simulations and other analyses to figure out what it would take.

    Researchers have come up with what they call the Space Hitchhike Equation, which relates the specific strength of the tether, the mass ratio between the spacecraft and the tether, and the change in velocity needed to accomplish the maneuver.

    In missions that use conventional propellant, spacecraft use a lot of fuel just to accelerate enough to get into orbit.

    “In Comet Hitchhiker, accelerating and decelerating do not require propellant because the spacecraft is harvesting kinetic energy from the target,” Ono said.

    For any spacecraft landing on a comet or asteroid, being able to slow down enough to arrive safely is critical. Comet Hitchhiker requires a tether made from a material that can withstand the enormous tension and heat generated by a rapid decrease in speed for getting into orbit and landing. Ono and colleagues calculated that a velocity change of about 0.9 miles (1.5 kilometers) per second is possible with some materials that already exist: Zylon and Kevlar.

    “That’s like going from Los Angeles to San Francisco in under seven minutes,” Ono said.

    But the bigger the velocity change required for orbit insertion, the shorter the flight time needed to get from Earth to the target — so if you want to get to a comet or asteroid faster, you need even stronger materials. A 6.2 mile-per-second (10 kilometer-per-second) velocity change is possible, but would require more advanced technologies such as a carbon nanotube tether and a diamond harpoon.

    Researchers also estimated that the tether would need to be about 62 to 620 miles long (100 to 1,000 kilometers) for the hitchhiking maneuver to work. It would also need to be extendable, and capable of absorbing jerks on it, while avoiding being damaged or cut by small meteorites.

    The next steps for studying the concept would be to do more high-fidelity simulations and try casting a mini-harpoon at a target that mimics the material found on a comet or asteroid.

    Comet Hitchhiker is in Phase I study through the NASA Innovative Advanced Concepts (NIAC) Program. NIAC is a program of NASA’s Space Technology Mission Directorate, located at the agency’s headquarters in Washington. Professor David Jewitt at the University of California, Los Angeles, partnered in this research.

    For a complete list of the selected proposals and more information about NIAC, visit:

    http://www.nasa.gov/niac

    For more information about the Space Technology Mission Directorate, visit:

    http://www.nasa.gov/spacetech

    See the full article here.

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    NASA JPL 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.

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  • richardmitnick 10:09 am on August 13, 2015 Permalink | Reply
    Tags: , , Comets,   

    From SPACE.com: “Comet and Rosetta Spacecraft Make Closest Approach to the Sun” 

    space-dot-com logo

    SPACE.com

    August 13, 2015
    Elizabeth Howell

    Temp 1

    After more than a year in orbit around a comet, the European Rosetta spacecraft and its icy dance partner are hitting a huge milestone: their closest approach to the sun.

    ESA Rosetta spacecraft
    Rosetta

    The Rosetta and its target, Comet 67P/Churyumov–Gerasimenko, reach perihelion today (Aug. 13), when the comet’s 6.5-year orbit brings it within 114.9 million miles (185 million kilometers) of the sun.

    Activity is already exploding on Comet 67P. In late July, Rosetta’s camera caught a jet erupting in the space of less than half an hour. And because it takes about a month for the comet to get its warmest, this means that activity is expected to peak in a few short weeks.

    2

    “The key to the Rosetta mission is that it is there for the long haul. It is there to watch and observe changes in the comet over time, with the same suite of instruments, as opposed to a flyby — or maybe different missions having flybys at different times with different instruments,” said Joel Parker, an interdisciplinary scientist on the mission. He is a research astronomer and director at the Southwest Research Institute in San Antonio, Texas.

    Rosetta arrived in orbit around Comet 67P on Aug. 6, 2014, nearly 10 years after launching into space. In November of last year, the orbiter’s small Philae lander touched down on the comet to study the object’s surface.

    “This is creating the baselines for all future study of comet activity for us to understand what is going on at the small scale, that cannot be observed from Earth or near-Earth observations,” Parker told Space.com.

    Among other things, researchers will learn about how the brightness of a comet increases, which could lead to better predictions for amateur astronomers, he said. Researchers will also look at how the composition of the comet’s emissions (dust and gas) change, which will provide clues about what the early universe looked like.

    How the solar system was

    Comets such as 67P are considered chunks of what the solar system appeared to be early in its formation, before the planets and moons were formed. Studying comets and asteroids therefore helps researchers understand the makeup of the young solar system shortly after its formation 4.5 billion years ago.

    Rosetta is the first spacecraft to orbit a comet and also the first to drop a small probe, the Philae comet lander, on a comet’s surface. Among other findings, the Rosetta mission revealed that the type of water on the comet is different than that of Earth, meaning that comets like 67P could not have delivered water to this planet. The spacecraft also detected organics, a building block to life on Earth, and possibly across the universe.

    There has been some discussion (and dispute) among the Rosetta researchers as to whether the comet’s outgassing will change as the object gets closer to the sun, said Paul Weissman, another Rosetta interdisciplinary scientist who recently retired from NASA’s Jet Propulsion Laboratory in California.

    Solar heating could unveil deeper regions of the comet that were untouched for millions or billions of years, depending on how much bled away when 67P passed by the sun previously.

    “This comet has this unusual … ratio” of the constituents of hydrogen in water, specifically the ratio of a rarer type of hydrogen, called deuterium, to hydrogen, Weissman said. “We’re curious to see if that changes as it goes around the sun and as it gets more active.

    Comet brightness

    It is notoriously difficult for even professional astronomers to predict how bright a comet will appear when it swings by Earth. This is because it’s difficult to see the nucleus (heart) of the comet, Parker said, so measurements are made from observing the comet or atmosphere.

    As Rosetta observes 67P from up close, the spacecraft will see how much gas is coming out, what dust the gas is dragging out and how big the gas particles are, Parker said. Weissman added that these particles could be a centimeter (0.4 inches) across or larger, which is big enough for the comet’s imaging instruments to resolve the individual particles and potentially, track their movements.

    The team will also be observing how the solar wind, the constant stream of gas from the sun, interacts with the comet’s surface and causes changes, Weissman said. The researchers will additionally watch how the coma of the comet – the dusty envelope around its nucleus – flexes when the solar wind hits it.

    Rosetta’s current mission ends on Sept. 30, 2016, when the mission will be operating at about four astronomical units or AU from Earth. (One astronomical unit is the Earth-sun distance, about 93 million miles or 150 million km.) At that point, the spacecraft will be so far from the sun that it will be difficult for its solar panels to collect the energy required to continue operating, so further work after that is unlikely, Weissman said.

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  • richardmitnick 3:19 pm on July 13, 2015 Permalink | Reply
    Tags: , , Comets,   

    From ESA: “Rosetta: preparing for perihelion” 

    ESASpaceForEuropeBanner
    European Space Agency

    13 July 2015
    No Writer Credit

    ESA Rosetta spacecraft
    Rosetta with Philae

    1
    Comet around perihelion

    Rosetta’s investigations of its comet are continuing as the mission teams count down the last month to perihelion – the closest point to the Sun along the comet’s orbit – when the comet’s activity is expected to be at its highest.

    Rosetta has been studying Comet 67P/Churyumov–Gerasimenko for over a year now, with observations beginning during the approach to the comet in March 2014. This included witnessing an outburst in late April 2014 and the revelation of the comet’s curious shape in early July.

    After arriving at a distance of 100 km from the double-lobed comet on 6 August, Rosetta has spent an intense year analysing the properties of this intriguing body – the interior, surface and surrounding dust, gas and plasma.

    Comets are known to be made of dust and frozen ices. As these ices are warmed by the Sun, they turn directly to vapour, with the gases dragging the comet’s dust along with it. Together, the gas and dust create a fuzzy atmosphere, or coma, and often-spectacular tails extend tens or hundreds of thousands of kilometres into space.

    2
    Comet on 25 June 2015 – NavCam

    While ground-based observations can monitor the development of the coma and tail from afar, Rosetta has a ringside seat for studying the source of this activity directly from the nucleus. One important aspect of Rosetta’s long-term study is watching how the activity waxes and wanes along the comet’s orbit.

    The comet has a 6.5 year commute around the Sun from just beyond the orbit of Jupiter at its furthest, to between the orbits of Earth and Mars at it closest.

    Rosetta rendezvoused with the comet around 540 million km from the Sun. Today, 13 July, a month from perihelion, this distance is much smaller: 195 million km. Currently travelling at around 120 000 km/h around their orbit, Rosetta and the comet will be 186 million km from the Sun by 13 August.

    “Perihelion is an important milestone in any comet’s calendar, and even more so for the Rosetta mission because this will be the first time a spacecraft has been following a comet from close quarters as it moves through this phase of its journey around the Solar System,” notes Matt Taylor, ESA’s Rosetta project scientist.

    “We’re looking forward to reaching perihelion, after which we’ll be continuing to monitor how the comet’s nucleus, activity and plasma environment changes in the year after, as part of our long-term studies.”

    See our FAQ below for more on what can you expect from perihelion and the activities planned around it.

    ————————————————————————-

    Perihelion basics

    4
    Comet’s orbit

    What is perihelion exactly?
    Perihelion is the closest point a Solar System object gets to the Sun along its orbit (aphelion is the term given to the most distant point). The term derives from ancient Greek, where ‘peri’ means near and ‘helios’ means Sun.

    How close to the Sun will the comet be at perihelion?
    Comet 67P/Churyumov–Gerasimenko is on a 6.5 year elliptical orbit around the Sun which takes it between 850 million km (5.68 AU) from the Sun at its most distant, just beyond the orbit of Jupiter, and 186 million km (1.24 AU) at its nearest, between the orbits of Earth and Mars. As a comparison, Earth orbits the Sun at an average distance of 149 million km (1 Astronomical Unit, or AU). .

    At what moment does perihelion occur?
    For this comet, the upcoming perihelion occurs at 02:03 GMT on 13 August 2015. The previous perihelion took place on 28 February 2009.

    The comet during perihelion

    5
    Comet activity 31 January – 25 March 2015

    What happens to the comet during perihelion? Will there be a big difference in activity in the coming weeks?
    The comet’s activity has been growing over the last year that Rosetta has been at the comet. This is an incremental process brought about by the increase in solar energy incident on the comet, warming up its frozen ices that subsequently sublimate. Rosetta has been witnessing this gradual rise, and scientists expect that this activity will reach a peak during August and September. Outbursts are possible, but unpredictable.

    Other comets plunge into the Sun at perihelion, what about this one?
    Comet 67P/Churyumov–Gerasimenko does not get close enough to the Sun to be destroyed by it; its closest point is actually further than Earth ever gets to the Sun and, furthermore, the comet has survived many previous orbits. It is not, for example, classed as a ‘sungrazer’ like Comet C/2012 S1 ISON, which broke apart during its perihelion passage in November 2013.

    Will Comet 67P/C-G break apart during perihelion?
    The comet has not broken apart during its many previous orbits, so it is not expected to do so this time, but it cannot be ruled out. Scientists are keen to watch the possible evolution of a 500 m-long fracture that runs along the surface of the neck on the comet during the peak activity.

    What happens to the comet after perihelion?
    As with the last observed perihelia, we expect the comet to continue on its orbit as normal, away from the Sun and back towards the outer Solar System again. Thanks to the heat absorbed during perihelion, the activity is expected to remain high for a couple of months before gently decreasing towards the moderate activity levels seen earlier in the mission, allowing Rosetta to get closer to the nucleus again.

    Rosetta and Philae during perihelion

    6
    Rosetta approaching comet

    Does Rosetta have to do any special manoeuvres for perihelion?
    Perihelion is a very different milestone to the other events such as waking up from hibernation, arriving at or landing on the comet where critical operations had to be carried out. Perihelion is simply a moment in time, and in terms of operations, it is business as usual – no special manoeuvres are required. The mission team hopes to have Rosetta as close as possible to the comet during perihelion to perform science observations without jeopardising the safety of the spacecraft, but this distance is currently decided on a twice-weekly basis for the week ahead, so the exact distance for perihelion is not currently known. During the last few months, it has not been possible to operate closer than 150 km without running into difficulties caused by the vast amounts of dust around the comet at the present time.

    Are there any special science observations that will be done at the time of perihelion?
    As with operations, it is also business as usual for science observations – monitoring of the comet and its dust, gas and plasma environment will continue during perihelion. Scientists are particularly keen to study the southern hemisphere of the comet, which has been in full sunlight only since May.

    How long will it take Rosetta to communicate with Earth on 13 August?
    The one-way signal travel time on 13 August is 14 min 44 sec.

    When will we see an image from the moment of perihelion?
    Rosetta’s Navigation Camera takes images several times during each 24 hour Earth day for navigation purposes, while the science camera OSIRIS has dedicated imaging slots. While the imaging schedule is not currently known for perihelion, we are hoping to be able to share both NavCam and OSIRIS image(s) with you from around the time of perihelion, during the afternoon of 13 August. Note that for OSIRIS this will depend on the data prioritisation on that day and the time it takes to downlink so this cannot be guaranteed. Time is also needed to check and process the images for release (for both NavCam and OSIRIS). We will update this section if/when more information about the timing of the image release(s) is known.

    Will Rosetta and Philae be safe during perihelion?
    Owing to the large amounts of dust, Rosetta will continue to operate at a safe distance from the comet throughout perihelion. We cannot predict any sudden increases in activity of the comet in advance, but the spacecraft safety remains – as always – a priority.

    Philae is on the surface of the comet, although its exact location remains unknown. Having regained communications with Rosetta on 13 June the link has been unpredictable and intermittent. The mission teams are carefully analysing the situation and hope that Philae will be operational during perihelion (separate updates on Philae’s condition will be made via the Rosetta Blog).

    What will happen to the mission after perihelion?
    Rosetta will continue to follow the comet as it moves back towards the outer Solar System, watching how the activity decreases over time and monitoring any post-perihelion changes that may occur. The Rosetta mission is scheduled to continue until September 2016, when the nominal planning would see Rosetta spiral down to the surface of the comet, where operations would likely end.

    8
    Comet from Earth – 22 May 2015

    Observing the comet from Earth during perihelion

    Why is perihelion interesting for astronomers?
    Near perihelion, comets reach their highest level of brightness, releasing large amounts of gas and dust. Possible outbursts and other unpredictable events might also take place around perihelion, so it is extremely important to obtain as many observations as possible during this period. While ground-based observations provide large-scale context for Rosetta’s measurements, Rosetta’s close-up data provide in turn the possibility to calibrate many of the observations made from the ground. This unique opportunity will also improve the study and interpretation of ground-based observations of other comets.

    How close to Earth will the comet be at perihelion? Is this the closest it gets to Earth?
    While the distance between the comet and the Sun decreases steadily until perihelion, before increasing again afterwards up to aphelion, the distance between Earth and the comet depends on their relative positions in the Solar System. At perihelion, the comet is 265 million km from Earth, but it will be closer (222 million km) during January–February 2016. Follow the positions of Rosetta and the comet through the Solar System using our Where is Rosetta? tool.

    Will astronomers be observing the comet at perihelion?
    Yes, a large network of professional and amateur astronomers has been observing the comet from across the globe in the past months. Observations with professional telescopes are planned every night around perihelion, relying on several robotic telescopes in many locations, and spectroscopic observations will be performed once a week. More details of the professional campaign are available here.

    How can I observe the comet at perihelion?
    Unfortunately, even at perihelion, the comet is too faint to be seen with the naked eye. To observe the comet, you will need a good telescope: a minimum of a 20 cm-aperture telescope is recommended. Guidance on how amateur astronomers can observe the comet is available here How can I observe the comet at perihelion?
    Unfortunately, even at perihelion, the comet is too faint to be seen with the naked eye. To observe the comet, you will need a good telescope: a minimum of a 20 cm-aperture telescope is recommended. Guidance on how amateur astronomers can observe the comet is available here.

    Until when is it possible to observe the comet from Earth?
    The comet is currently passing from the southern sky to the northern sky, so its visibility depends on where you live. Around the time of perihelion, it can be observed from Earth in the early morning hours, just before sunrise. It will remain relatively close to the Sun in the sky, and thus observable in the early morning, for several months. Then, the comet will be in the night sky between December 2015 and March 2016, which will be the prime time for ground-based observations. By the middle of 2016 it will likely be too faint to see except by large telescopes owing to its distance from the Sun and Earth, and it will also start moving behind the Sun as seen from Earth.

    Media

    Will there be any special events to mark the occasion of perihelion?
    Members of the public and media are invited to join an online Google+ Hangout on 13 August, during which we hope to have one or more images on the ground from around the time of perihelion. Time and guests to be announced nearer the time.

    How can I follow online?
    You can follow the mission in a number of ways (see esa.int/rosetta for an overview). On Twitter, official updates will be made by @ESA_Rosetta using the hashtag #perihelion2015. Information will also be provided by the Rosetta blog and on the Rosetta Mission Facebook page. The image(s) from perihelion will be published on our main ESA web portal, esa.int, in an official press release. The Google+ Hangout will also be advertised on esa.int and will be available to watch live via ESA’s G+ page and later as a replay on G+ and ESA’s YouTube channel.

    See the full article here.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 10:33 am on June 2, 2015 Permalink | Reply
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    From ESA: “Ultraviolet study reveals surprises in comet coma” 

    ESASpaceForEuropeBanner
    European Space Agency

    For more information, please contact:

    Markus Bauer







    ESA Science and Robotic Exploration Communication Officer








    Tel: +31 71 565 6799








    Mob: +31 61 594 3 954








    Email: markus.bauer@esa.int

    Paul Feldman
    Johns Hopkins University, Baltimore
    Email: pfeldman@jhu.edu

    Matt Taylor






    ESA Rosetta project scientist






    Email: matthew.taylor@esa.int

    Rosetta’s continued close study of Comet 67P/Churyumov–Gerasimenko has revealed an unexpected process at work, causing the rapid breakup of water and carbon dioxide molecules spewing from the comet’s surface.

    ESA Rosetta spacecraft
    Rosetta

    ESA’s Rosetta mission arrived at the comet in August last year. Since then, it has been orbiting or flying past the comet at distances from as far as several hundred kilometres down to as little as 8 km. While doing so, it has been collecting data on every aspect of the comet’s environment with its suite of 11 science instruments.

    One instrument, the Alice spectrograph provided by NASA, has been examining the chemical composition of the comet’s atmosphere, or coma, at far-ultraviolet wavelengths.

    At these wavelengths, Alice allows scientists to detect some of the most abundant elements in the Universe such as hydrogen, oxygen, carbon and nitrogen. The spectrograph splits the comet’s light into its various colours – its spectrum – from which scientists can identify the chemical composition of the coma gases.


    Rosetta’s imaging and spectroscopy instruments

    In a paper accepted for publication in the journal Astronomy and Astrophysics, scientists report the detections made by Alice from Rosetta’s first four months at the comet, when the spacecraft was between 10 km and 80 km from the centre of the comet nucleus.

    For this study, the team focused on the nature of ‘plumes’ of water and carbon dioxide gas erupting from the comet’s surface, triggered by the warmth of the Sun. To do so, they looked at the emission from hydrogen and oxygen atoms resulting from broken water molecules, and similarly carbon atoms from carbon dioxide molecules, close to the comet nucleus.

    They discovered that the molecules seem to be broken up in a two-step process.

    First, an ultraviolet photon from the Sun hits a water molecule in the comet’s coma and ionises it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energising them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice.

    Similarly, it is the impact of an electron with a carbon dioxide molecule that results in its break-up into atoms and the observed carbon emissions.

    “Analysis of the relative intensities of observed atomic emissions allows us to determine that we are directly observing the ‘parent’ molecules that are being broken up by electrons in the immediate vicinity, about 1 km, of the comet’s nucleus where they are being produced,” says Paul Feldman, professor of physics and astronomy at the Johns Hopkins University in Baltimore, and lead author of the paper discussing the results.

    By comparison, from Earth or from Earth-orbiting space observatories such as the Hubble Space Telescope, the atomic constituents of comets can only be seen after their parent molecules, such as water and carbon dioxide, have been broken up by sunlight, hundreds to thousands of kilometres away from the nucleus of the comet.

    2
    Comet on 20 May 2015 – NavCam

    “The discovery we’re reporting is quite unexpected,” says Alice Principal Investigator Alan Stern, an associate vice president in the Space Science and Engineering Division of the Southwest Research Institute (SwRI).

    “It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets.”

    “By looking at the emission from hydrogen and oxygen atoms broken from the water molecules, we also can actually trace the location and structure of water plumes from the surface of the comet,” adds co-author Joel Parker, an assistant director in SwRI’s Space Science and Engineering Division in Boulder, Colorado.

    The team likens the break-up of the molecules to the process that has been proposed for the plumes on Jupiter’s icy moon Europa, except that the electrons at the comet are produced by solar photons, while the electrons at Europa come from Jupiter’s magnetosphere.

    The results from Alice are supported by data obtained by other Rosetta instruments, in particular MIRO, ROSINA and VIRTIS, which are able to study the abundance of different coma constituents and their variation over time, and particle detecting instruments like RPC-IES.

    “These early results from Alice demonstrate how important it is to study a comet at different wavelengths and with different techniques, in order to probe various aspects of the comet environment,” says ESA’s Rosetta project scientist Matt Taylor.

    “We’re actively watching how the comet evolves as it moves closer to the Sun along its orbit towards perihelion in August, seeing how the plumes become more active due to solar heating, and studying the effects of the comet’s interaction with the solar wind.”

    More information

    Measurements of the near-nucleus coma of Comet 67P/Churyumov-Gerasimenko with the Alice far-ultraviolet spectrograph on Rosetta, by P Feldman et al is accepted for publication in Astronomy and Astrophysics.

    About Rosetta
    Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was provided by a consortium led by DLR, MPS, CNES and ASI.

    ESA Rosetta Philae Lander
    Rosetta’s Philae lander

    Rosetta is the first mission in history to rendezvous with a comet. It is escorting the comet as they orbit the Sun together. Philae landed on the comet on 12 November 2014. Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System.

    See the full article here.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 7:46 am on May 26, 2015 Permalink | Reply
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    From NAOJ: “The Deep Impact Mission Investigates the Origin of Comets” 

    NAOJ

    NAOJ

    Astrophotography・May 26, 2015
    Text by: Seiji Sugita (The University of Tokyo)
    Translation by: Ramsey Lundock (NAOJ)

    1

    Sequential photographs in the mid-infrared show the conditions from one hour to several hours after the impactor released from the Deep Impact flyby spacecraft collided with the Jovian Comet Tempel 1.

    NASA Deep Impact spacecraft
    NASA/Deep Impact spacecreft

    The red color shows carbon-rich material and green shows material rich in silicates (the main component of normal rocks). We can see that for several hours after the collision, the comet’s internal material expanded rapidly out into space, forming a fan shape. The results showed that the internal composition of Jovian (short-period) comets and long-period comets are extremely similar. This is very important data for theories about the origin of comets.

    Long-period Comets and Jovian Comets

    Long-period comets and Jovian comets differ both in terms of their momentum and in terms of the types of dust and gas which they expel. This is thought that they hail primarily from, respectively, the Oort Cloud at a distance of tens of thousands of astronomical units (au) from the Sun and the Kuiper Belt in the vicinity of 30-50 au. Whether the composition of objects is similar or different in these two very different locations is important information for understanding the origin of the Solar System.

    2
    An artist’s rendering of the Oort cloud and the Kuiper belt (inset). Sizes of individual objects have been exaggerated for visibility.

    3
    Known objects in the Kuiper belt beyond the orbit of Neptune (scale in AU; epoch as of January 2015).

    But it was not known whether the difference between these two species of comets is a difference in the depletion levels of gas and dust, or if it is a difference in the internal composition from the time of formation.

    To determine which is correct, it is necessary to peel off the gas-and-dust-depleted surface of a Jovian comet and observe the excavated pristine interior. This experiment was the goal of the Deep Impact Mission.

    On the night of the experiment, we watched the experiment unfold from the summit of Mauna Kea. As the activity started to subside, it came as a big surprise as pristine silicate particles, typical of long-period comets, gushed out from the interior of the Jovian comet. The interiors of both have similar compositions.

    See the full article here.

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

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    Solar Flare Telescope

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    Nobeyama Radio Observatory: Solar

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    Mizusawa VERA Observatory

    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 5:21 pm on January 22, 2015 Permalink | Reply
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    From Nature: “Science pours in from Rosetta comet mission” 

    Nature Mag
    Nature

    22 January 2015
    Elizabeth Gibney

    The first major haul of research from the European Space Agency’s Rosetta mission, published in seven papers in Science on 22 January, reveals a rich and diverse landscape on 67P/Churyumov–Gerasimenko, the most studied comet in history. The best images from the haul are pictured below.

    1
    Charting gravity
    Using data from the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) and the Radio Science Investigation instrument, the Rosetta mission team calculated the comet’s gravitational field1. The gravitational potential (pictured) also takes into account a pull caused by the comet’s rotation. The resulting force is greatest on top of the lobes, but it is about six times weaker in the neck region, where dust can lift off more easily. The team also used the data to calculate the comet’s density, finding that the body is relatively fluffy and porous — with a density of around half that of water, giving clues as to its structure and strength.

    2
    Different terrains
    Images taken by the OSIRIS camera reveal vastly different kinds of terrain, including dunes, ripples and fractures2. Rosetta scientists have split the comet into regions defined by surface structure (see false-colour image), with each named after an Egyptian god. Hatmehit, for example, is a smooth depression on the ‘head’ of the duck-shaped comet that could be a dust-filled impact crater. Other areas, such as Seth and Hathor, are rough with steep cliff-like structures. However, the porosity of the comet means that rock-like structures are in fact compacted dust. Many structures look as though they are formed by gas moving dust around the surface, say the authors, in the same way that wind shapes sand in a desert

    3
    Clues to the origins
    Detailed pictures, at their best with a resolution of 15 centimetres per pixel, show structures that could hint at the comet’s history1. Three-metre-wide features nicknamed “goosebumps”, pictured here running down the inside of a pit in the Seth region, are found all over the comet. Holger Sierks of the Max Planck Institute for Solar System Research in Göttingen, Germany, who is principal investigator on the OSIRIS camera instrument, says that the pebble-like shapes could hint at the scale on which grains of dust and ice first clumped together in the early Solar System. “The hypothesis is these might be the building blocks of comets,” he says.

    4
    The neck riddle
    Data from several instruments show that the comet’s neck is the source of most of its streaming gas and dust. To understand why the region is so active, the Rosetta team looked at how much thermal energy hits the surface per 12.4-hour rotation (left) and per 6.5-year solar orbit (right). The neck receives less energy from the Sun than the rest of the comet because it is shaded, but they found that a suntrap effect from radiation bouncing between opposite cliff walls goes some way towards compensating for that. Other possible reasons for the region’s high activity include its low gravitational pull, which means that little force is needed to blow dust away, and that the region might have a different composition than other regions, or have more ready access to water beneath the surface1. The team has still to answer whether the neck denotes a join between two comets or has been carved out of a single comet by erosion. Evidence of differences between the two lobes would indicate the former, but so far the two lobes seem to have very similar structures, says Sierks.

    6
    Coming from afar
    This visible and infrared portrait of 67P’s surface, obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), shows an abundance of opaque, organic compounds, but very little water ice. This would be consistent with an origin for the comet in the distant Kuiper belt — beyond the orbit of Neptune — rather than closer to Jupiter, as its current orbit would suggest.

    References
    1.Sierks, H. et al. Science http://dx.doi.org/10.1126/science.aaa1044 (2015)
    2.Thomas, N. et al. Science http://dx.doi.org/10.1126/science.aaa0440 (2015)
    3.Hässig, M. et al. Science http://dx.doi.org/10.1126/science.aaa0276 (2015)
    4.Capaccioni, F. et al. Science http://dx.doi.org/10.1126/science.aaa0628 (2015)
    6.Gulkis, S. et al. Science http://dx.doi.org/10.1126/science.aaa0709 (2015)

    Additional reporting by Davide Castelvecchi

    See the full article here.

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    Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.

     
  • richardmitnick 7:14 am on January 17, 2015 Permalink | Reply
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    From JPL: “NASA’s NEOWISE Images Comet C/2014 Q2 (Lovejoy) “ 

    JPL

    1
    Image credit: NASA/JPL-Caltech

    Comet C/2014 Q2 (Lovejoy) is one of more than 32 comets imaged by NASA’s NEOWISE mission from December 2013 to December 2014. This image of comet Lovejoy combines a series of observations made in November 2013, when comet Lovejoy was 1.7 astronomical units from the sun. (An astronomical unit is the distance between Earth and the sun.)

    The image spans half of one degree. It shows the comet moving in a mostly west and slightly south direction. (North is 26 degrees to the right of up in the image, and west is 26 degrees downward from directly right.) The red color is caused by the strong signal in the NEOWISE 4.6-micron wavelength detector, owing to a combination of gas and dust in the comet’s coma.

    Comet Lovejoy is the brightest comet in Earth’s sky in early 2015. A chart of its location in the sky during dates in January 2015 is at http://photojournal.jpl.nasa.gov/catalog/PIA19103 .

    For more information about NEOWISE (the Near-Earth Object Wide-field Survey Explorer), see http://neowise.ipac.caltech.edu/.

    NASA Wise Telescope
    NASA/Wise

    See the full article here.

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    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.

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