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The Last Month in Astronomy


04-MAY-2011 • Comet Elenin • Astronomer Leonid Elenin discovered the comet also known as C/2010 X1 on December 10, 2010. The comet may be visible to the naked eye near the time of its closest approach mid-October 2011. At that time, it will be 22 million miles away. Some speculations about how close it might come or how it might affect Earth weather have no scientific basis.

02-MAY-2011 • Space helps Windows • A gas sensor built to measure atomic oxygen in space including outside of the International Space Station is being used by a German window maker to make more energy efficient buildings. The ISS measures oxygen in the “vacuum” of space because of its corrosive effects including degrading optical surfaces.

28-APR-2011 • Voyagers Leaving • The 2 Voyager probes are about to leave the last part of the solar system. It is now in the heliosheath which is 3 to 4 billion miles in thickness. It might “pop free” within the next 5 years. The plutonium based energy source should keep the Voyagers running until 2020 or later.

25-APR-2011 • First images from Messenger • The Messenger spacecraft has sent back the first images from its orbit around Mercury. See the image on the right. The image was acquired on April 10, 2011. The bright crater is called Kuiper. Messenger is the first spacecraft to orbit Mercury. During its one year planned mission 75,000 images will be transmitted to Earth. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

21-APR-2011 • Mars Orbiter sees atmospheric changes • The Mars Reconnaissance Orbiter (MRO) has discovered evidence that the total amount of atmosphere on Mars has changed dramatically as the planet’s tilt changes. The radar evidence is a large deposit of frozen carbon dioxide below the surface of the south pole. When the planet’s tilt is greater than it is now, the Lake Superior-sized chunk of dry ice melts. According to Roger Phillips of Southwest Research Institute (Boulder, CO), “When you include this buried deposit, Martian carbon dioxide right now is roughly half frozen and half in the atmosphere, but at other times it can be nearly all frozen or nearly all in the atmosphere”. The MRO’s Shallow Radar is one of 6 instruments on board the spacecraft.

21-APR-2011 • Plump UV Stars • NASA’s GALEX spacecraft is helping to find out why some of the most massive stellar explosions seem to occur in the smallest galaxies. The answer may be that massive stars in small galaxies stay massive but similar sized stars in large galaxies are whittled away over time so that by the time they explode they are not so large. The mystery was first pointed out by Neil deGrasse Tyson and John Scalo. They noticed supernovae in places where there don’t seem to be any galaxies at all. They proposed that dwarf galaxies were the actual source of the explosions and new data from the Palomar Observatory bears this out.

20-APR-2011 • Electricity at Saturn • There is an electrical connection between Saturn and Enceladus which forms an auroral footprint. This connection had been proposed ever since a similar connection between Jupiter and IO was discovered. Marcia Burton, a Cassini scientist at JPL says “The footprint discovery at Saturn is one of the most important fields and particle revelations from Cassini and ultimately may help us understand Saturn’s strange magnetic field. It gives us the first visual connection between Saturn and one of its moons.”


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