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The Last Month in Astronomy

The Swan Nebula


JUN-13-2009 • Odds of Life Doubles • The chance of finding life on another planet has doubled. That’s because scientists at Caltech believe that life increases the lifespan of the biosphere. Thus that factor in the Drake equation is doubled and thus so is the final result. How does this happen? Life can reduce the increased air pressure by removing large amounts of molecular nitrogen. This regulates surface temperatures and, in the case of Earth, could add 1.3 billion years to Earth’s lifespan.

JUN-16-2009 • The Betelgeuse Diet • The star Betelgeuse has shrunk about 1 percent per year for the last 15 years. Of course, Betelgeuse had a lot to lose. It had a diameter of 5.5 AU. The distance to Betelgeuse is now set at 640 light years (previously thought to be 430 light years).

JUN-18-2009 • LRO/LCROSS Launched • The Lunar Reconnaissance Orbiter and the LCROSS impactor were launched and first images were available about 2 weeks later.

JUN-24-2009 • Salt on Enceladus • Sodium has been detected by the Cassini spacecraft. This suggests that there might be salty oceans on Enceladus. But another ground-based study indicates no salt on Enceladus. These two findings might mean that there is some salt on this Saturnian moon but not a lot.

JUN-25-2009 • Shuttle finds Tunguska evidence • The 1908 Tunguska explosion was likely caused by a comet hitting the Earth’s atmosphere. That is the conclusion from a NASA space shuttle. The connection between the two is that noctilucent clouds were found after Tunguska and after a shuttle launch. Every space shuttle flight puts 300 tons of water vapor into the atmosphere. This water vapor can move to the poles and form clouds.

JUL-06-2009 • New Details in NGC 7293 • A new image taken with the infrared camera on the Subaru Telescope in Hawaii shows tens of thousands of comet-shaped knots inside the nebula. This nebula is one of the closest, only 710 light years away. The total number of these knots might be 40,000 in the whole nebula. The total mass of the knots is one-tenth the mass of the Sun.

JUL-07-2009 • Swan Nebula image • A new picture of the Swan Nebula (aka Omega Nebula, M17) gives a glittering view of the stellar nursery. The photo was taken by the ESO telescope in La Silla, Chile.

JUL-09-2009 • Galileo discovered Neptune? • It has been known for some time that some of Galileo’s drawings show Neptune as a background star. The standard explanation is that Galileo didn’t notice that Neptune was moving very slowly. But a new theory suggests that Galileo did know that he had found a new planet in 1613, 234 years before Neptune was really found. How to prove that? Galileo often wrote anagrams for some of this discoveries like the rings of Saturn. Perhaps another anagram is buried in his notes or letters.


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