Planet-sized space weather explosions at Venus

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/juPtrlZ3Jjo

Researchers recently discovered that a common space weather phenomenon on the outskirts of Earth’s magnetic bubble, the magnetosphere, has much larger repercussions for Venus. The giant explosions, called hot flow anomalies, can be so large at Venus that they’re bigger than the entire planet and they can happen multiple times a day.”Not only are they gigantic,” said Glyn Collinson, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “But as Venus doesn’t have a magnetic field to protect itself, the hot flow anomalies happen right on top of the planet. They could swallow the planet whole.”Collinson is the first author of a paper on these results that appeared online in the Journal of Geophysical Research in February 2014. The work is based on observations from the European Space Agency’s Venus Express. The results show just how large and how frequent this kind of space weather is at Venus.Earth is protected from the constant streaming solar wind of radiation by its magnetosphere. Venus, however, has no such luck. A barren, inhospitable planet, with an atmosphere so dense that spacecraft landing there are crushed within hours, Venus has no magnetic protection.Scientists like to compare the two: What happened differently at Earth to make it into the life-supporting planet it is today? What would Earth be like without its magnetic field?At Earth, hot flow anomalies do not make it inside the magnetosphere, but they release so much energy just outside that the solar wind is deflected, and can be forced to move back toward the sun. Without a magnetosphere, what happens at Venus is very different.Venus’s only protection from the solar wind is the charged outer layer of its atmosphere called the ionosphere. …


Read More: Planet-sized space weather explosions at Venus

#Alternative-Medicine, #Cancer, #Earth, #Flight, #Geophysical, #Giant, #Goddardspace, #Nasa, #Pregnancy, #Science

Astronomers get first peek into core of supernova, using NuSTAR telescope

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/ETg1piovjCQ

Astronomers for the first time have peered into the heart of an exploding star in the final minutes of its existence.The feat is one of the primary goals of NASA’s NuSTAR mission, launched in June 2012 to measure high-energy X-ray emissions from exploding stars, or supernovae, and black holes, including the massive black hole at the center of our Milky Way Galaxy.The NuSTAR team reported in this week’s issue of the journal Nature the first map of titanium thrown out from the core of a star that exploded in 1671. That explosion produced the beautiful supernova remnant known as Cassiopeia A (Cas A).The well-known supernova remnant has been photographed by many optical, infrared and X-ray telescopes in the past, but these revealed only how the star’s debris collided in a shock wave with the surrounding gas and dust and heated it up. NuSTAR has produced the first map of high-energy X-ray emissions from material created in the actual core of the exploding star: the radioactive isotope titanium-44, which was produced in the star’s core as it collapsed to a neutron star or black hole. The energy released in the core collapse supernova blew off the star’s outer layers, and the debris from this explosion has been expanding outward ever since at 5,000 kilometers per second.”This has been a holy grail observation for high energy astrophysics for decades,” said coauthor and NuSTAR investigator Steven Boggs, UC Berkeley professor and chair of physics. “For the first time we are able to image the radioactive emission in a supernova remnant, which lets us probe the fundamental physics of the nuclear explosion at the heart of the supernova like we have never been able to do before.”"Supernovae produce and eject into the cosmos most of the elements are important to life as we know it,” said UC Berkeley professor of astronomy Alex Filippenko, who was not part of the NuSTAR team. “These results are exciting because for the first time we are getting information about the innards of these explosions, where the elements are actually produced.”Boggs says that the information will help astronomers build three-dimensional computer models of exploding stars, and eventually understand some of the mysterious characteristics of supernovae, such as jets of material ejected by some. Previous observations of Cas A by the Chandra X-ray telescope, for example, showed jets of silicon emerging from the star.”Stars are spherical balls of gas, and so you might think that when they end their lives and explode, that explosion would look like a uniform ball expanding out with great power,” said Fiona Harrison, the principal investigator of NuSTAR at the California Institute of Technology. “Our new results show how the explosion’s heart, or engine, is distorted, possibly because the inner regions literally slosh around before detonating.”Expanding supernova remnantCas A is about 11,000 light years from Earth and the most studied nearby supernova remnant. In the 343 years since the star exploded, the debris from the explosion has expanded to about 10 light years across, essentially magnifying the pattern of the explosion so that it can be seen from Earth.Earlier observations of the shock-heated iron in the debris cloud led some astronomers to think that the explosion was symmetric, that is, equally powerful in all directions. Boggs noted, however, that the origins of the iron are so unclear that its distribution may not reflect the explosion pattern from the core.”We don’t know whether the iron was produced in the supernova explosion, whether it was part of the star when it originally formed, if it is just in the surrounding material, or even if the iron we see represents the actual distribution of iron itself, because we wouldn’t see it if it were not heated in the shock,” he said.The new map of titanium-44, which does not match the distribution of iron in the remnant, strongly suggests that there is cold iron in the interior that Chandra does not see. …


Read More: Astronomers get first peek into core of supernova, using NuSTAR telescope

#Alzheimer, #Berkeley, #Cancer, #Chandra, #Distribution, #Explosion, #Nasa, #Pregnancy, #Science, #Space, #Star, #William

Responding to potential asteroid redirect mission targets

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/3l8C3oGKxxQ

One year ago, on Feb. 15, 2013, the world was witness to the dangers presented by near-Earth Objects (NEOs) when a relatively small asteroid entered Earth’s atmosphere, exploding over Chelyabinsk, Russia, and releasing more energy than a large atomic bomb. Tracking near-Earth asteroids has been a significant endeavor for NASA and the broader astronomical community, which has discovered 10,713 known near-Earth objects to date. NASA is now pursuing new partnerships and collaborations in an Asteroid Grand Challenge to accelerate NASA’s existing planetary defense work, which will help find all asteroid threats to human population and know what to do about them. In parallel, NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth’s moon for future exploration by astronauts in the 2020s.ARM will use capabilities in development, including the new Orion spacecraft and Space Launch System (SLS) rocket, and high-power Solar Electric Propulsion. All are critical components of deep-space exploration and essential to meet NASA’s goal of sending humans to Mars in the 2030s. The mission represents an unprecedented technological feat, raising the bar for human exploration and discovery, while helping protect our home planet and bringing us closer to a human mission to one of these intriguing objects.NASA is assessing two concepts to robotically capture and redirect an asteroid mass into a stable orbit around the moon. In the first proposed concept, NASA would capture and redirect an entire very small asteroid. In the alternative concept, NASA would retrieve a large, boulder-like mass from a larger asteroid and return it to this same lunar orbit. In both cases, astronauts aboard an Orion spacecraft would then study the redirected asteroid mass in the vicinity of the moon and bring back samples.Very few known near-Earth objects are ARM candidates. …


Read More: Responding to potential asteroid redirect mission targets

#Atomic, #Defense, #Nasa, #Objectprogram, #Orbit, #Planet, #Program, #Result, #Space

Cosmic roadmap to galactic magnetic field revealed

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/Wh5EztadtKo

Scientists on NASA’s Interstellar Boundary Explorer (IBEX) mission, including a team leader from the University of New Hampshire, report that recent, independent measurements have validated one of the mission’s signature findings — a mysterious “ribbon” of energy and particles at the edge of our solar system that appears to be a directional “roadmap in the sky” of the local interstellar magnetic field.Unknown until now, the direction of the galactic magnetic field may be a missing key to understanding how the heliosphere — the gigantic bubble that surrounds our solar system — is shaped by the interstellar magnetic field and how it thereby helps shield us from dangerous incoming galactic cosmic rays. “Using measurements of ultra-high energy cosmic rays on a global scale, we now have a completely different means of verifying that the field directions we derived from IBEX are consistent,” says Nathan Schwadron, lead scientist for the IBEX Science Operations Center at the UNH Institute for the Study of Earth, Oceans, and Space. Schwadron and IBEX colleagues published their findings online today in Science.Establishing a consistent local interstellar magnetic field direction using IBEX low-energy neutral atoms and galactic cosmic rays at ten orders of magnitude higher energy levels has wide-ranging implications for the structure of our heliosphere and is an important measurement to be making in tandem with the Voyager 1 spacecraft, which is in the process of passing beyond our heliosphere.”The cosmic ray data we used represent some of the highest energy radiation we can observe and are at the opposite end of the energy range compared to IBEX’s measurements,” says Schwadron. “That it’s revealing a consistent picture of our neighborhood in the galaxy with what IBEX has revealed gives us vastly more confidence that what we’re learning is correct.”How magnetic fields of galaxies order and direct galactic cosmic rays is a crucial component to understanding the environment of our galaxy, which in turn influences the environment of our entire solar system and our own environment here on Earth, including how that played into the evolution of life on our planet.Notes David McComas, principal investigator of the IBEX mission at Southwest Research Institute and coauthor on the Science Express paper, “We are discovering how the interstellar magnetic field shapes, deforms, and transforms our entire heliosphere.”To date, the only other direct information gathered from the heart of this complex boundary region is from NASA’s Voyager satellites. Voyager 1 entered the heliospheric boundary region in 2004, passing beyond what’s known as the termination shock where the solar wind abruptly slows. Voyager 1 is believed to have crossed into interstellar space in 2012.Interestingly, when scientists compared the IBEX and cosmic ray data with Voyager 1′s measurements, the Voyager 1 data provide a different direction for the magnetic fields just outside our heliosphere.That’s a puzzle but it doesn’t necessarily mean one set of data is wrong and one is right. Voyager 1 is taking measurements directly, gathering data at a specific time and place, while IBEX gathers information averaged over great distances — so there is room for discrepancy. Indeed, the very discrepancy can be used as a clue: understand why there’s a difference between the two measurements and gain new insight.”It’s a fascinating time,” says Schwadron. “Fifty years ago, we were making the first measurements of the solar wind and understanding the nature of what was just beyond near-Earth space. Now, a whole new realm of science is opening up as we try to understand the physics all the way outside the heliosphere.”Eberhard Mbius, UNH principal scientist for the IBEX-Lo instrument on board, is a coauthor on the Science paper along with colleagues from institutions around the country.Story Source:The above story is based on materials provided by University of New Hampshire. …


Read More: Cosmic roadmap to galactic magnetic field revealed

#Agriculture, #Heliosphere, #Institute, #Interstellar, #King, #Nasa, #Neighborhood, #Pregnancy, #Process, #Science, #Space, #University

Looking back to the cradle of our universe: Astronomers spot what may be one of most distant galaxies known

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/GnrxOu2fxvg

NASA’s Spitzer and Hubble Space Telescopes have spotted what might be one of the most distant galaxies known, harkening back to a time when our universe was only about 650 million years old (our universe is 13.8 billion years old). The galaxy, known as Abell2744 Y1, is about 30 times smaller than our Milky Way galaxy and is producing about 10 times more stars, as is typical for galaxies in our young universe.The discovery comes from the Frontier Fields program, which is pushing the limits of how far back we can see into the distant universe using NASA’s multi-wavelength suite of Great Observatories. Spitzer sees infrared light, Hubble sees visible and shorter-wavelength infrared light, and NASA’s Chandra X-ray Observatory sees X-rays. The telescopes are getting a boost from natural lenses: they peer through clusters of galaxies, where gravity magnifies the light of more distant galaxies.The Frontier Fields program will image six galaxy clusters in total. Hubble images of the region are used to spot candidate distant galaxies, and then Spitzer is needed to determine if the galaxies are, in fact, as far as they seem. Spitzer data also help determine how many stars are in the galaxy.These early results from the program come from images of the Abell 2744 galaxy cluster. The distance to this galaxy, if confirmed, would make it one of the farthest known. Astronomers say it has a redshift of 8, which is a measure of the degree to which its light has been shifted to redder wavelengths due to the expansion of our universe. The farther a galaxy, the higher the redshift. The farthest confirmed galaxy has a redshift of more than 7. …


Read More: Looking back to the cradle of our universe: Astronomers spot what may be one of most distant galaxies known

#Alternative-Medicine, #California, #Frontier, #Galaxies, #Health, #Institute, #Nasa, #Pregnancy, #Program, #Technology, #Years