This week I recommend to follow @NASAKepler for interesting tweets from NASA’s Kepler Mission, designed to survey our region of the Milky Way galaxy to discover Earth-size planets in the habitable zone. For more Twitter follow suggestions see our astronomy list @TheAstroBlog/astronomy
Massive Asteroid to Hit Earth in 2040? Scientists are keeping a close eye on a big asteroid that may pose an impact threat to Earth in a few decades. The space rock, which is called 2011 AG5, is about 140 meters wide. It may come close enough to Earth in 2040 that some researchers are calling for a discussion about how to deflect it. Talk about the asteroid was on the agenda during the 49th session of the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), held earlier this month in Vienna. Searching for the First Stars Recently, astronomers found two immense clouds of pristine gas, nearly 12 billion light years away — clouds that astronomers suspect are the stuff from which the first stars were born. The Kavli Foundation spoke with three prominent researchers about this and other exciting findings that are moving scientists closer to understanding how the first stars and galaxies formed. This includes the realization that in early times, there were many more small, feeble galaxies than large luminous galaxies. Swiss space debris effort could open the political door to space debris removal The Swiss Space Center at the Swiss Federal Institute for Technology in Lausanne announced on February 15 its plan to develop and launch a satellite to remove space debris from low Earth orbit. The $11-million satellite, called CleanSpace One, is intended to actively intercept and de-orbit one of two Swiss satellites: the Swisscube-1 picosatellite, launched in 2009, or its cousin TIsat-1, which are each cubes 10 centimeters on a side.
Mysterious Electron Acceleration Explained: Computer Simulation Identifies Source of Aurora-Causing High-Speed Electrons in Space A mysterious phenomenon detected by space probes has finally been explained, thanks to a massive computer simulation that was able to precisely align with details of spacecraft observations. The finding could not only solve an astrophysical puzzle, but might also lead to a better ability to predict high-energy electron streams in space that could damage satellites. The cislunar econosphere (part 2) The next hurdle is a difficult one. Facilities could be established in GEO orbit that would be quite useful in dealing with things in that neighborhood, like harvesting the zombiesats. However, there is a better destination a bit farther out at the Earth-Moon L-1 point. As can be noted in the diagram above, the delta-V (change in velocity) cost is less than that of going just from LEO to GEO. The delta-V cost of going from LEO to EML1, and then back down to GEO, is the same as a median delta-V from LEO straight to GEO. Astronomers Rediscover Life On Earth — By Looking at the Moon By observing the Moon using ESO’s Very Large Telescope, astronomers have found evidence of life in the Universe — on Earth. Finding life on our home planet may sound like a trivial observation, but the novel approach of an international team may lead to future discoveries of life elsewhere in the Universe. The work is described in a paper to appear in the 1 March 2012 issue of the journal Nature. Open issues with the official Phobos-Grunt accident report With the release in Moscow on February 3 of the summary report from the investigation commission for the Phobos-Grunt debacle, the story has dropped from the news. But that is a pity because the report itself shows it is by no means the end of the story of this heartbreaking Russian space setback. If the official cause of the failure — cosmic rays knocking out two separate computer circuits simultaneously — is not accurate, then remedial actions and get-well measures will be inappropriate and very possibly ineffective. Spinning Star’s Vanishing Act Reveals Cosmic Mystery Pulsars are fast-spinning stars that emit regular beams of light known for their clocklike regularity. So, when one strangely turned off for a year and a half, astronomers were surprised to find that this abnormality could help them solve the longstanding mystery of what makes these flashing stars tick. Despite more than forty years of study, astronomers still can’t nail down what causes these rapidly rotating stars to pulse. But when one, called PSR J1841, turned off for 580 days, it gave astronomers a glimpse of how pulsars behave when they can’t be seen. The critical year for commercial cargo and crew In 2005, then NASA administrator Michael Griffin announced plans to support the development of commercial systems to transport cargo, and potentially humans, to and from the International Space Station. The idea of this concept, which became the Commercial Orbital Transportation Services (COTS) program, was to create a new market for commercial space activities, allowing companies to meet NASA’s needs — and those of other potential customers — at a lower cost than a traditional government system, freeing up NASA resources for exploration missions beyond Earth orbit. New Model Provides Different Take On Planetary Accretion: Collapse May Take Place in 3-D Cold Dust Cloud The prevailing model for planetary accretion, also called fractal assembly, and dating back as far as the 18th century, assumes that the Solar System’s planets grew as small grains colliding chaotically, coalescing into bigger ones, colliding yet more until they formed planetesimals. The planetesimals then collided until they formed planets as varied as Earth and Jupiter.
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