Tuesday, July 21, 2009

News bites of July 2009

Sometimes the news rolls in just too fast to comment on. Add in two trips to west Texas in two weeks, a bout with a stomach bug resulting in an Urgent Care visit in Ozona, Texas, and telescope deadlines, and it becomes even worse. Here is the cool news of the past several days that I haven't had any time to blog about:

  • Jupiter 2, Comets 0 On the morning of Sunday, July 19, Australian amateur astronomer Anthony Wesley was taking images of the planet Jupiter when he noticed a black spot near the planet's south pole. Subsequent observations found pretty conclusive evidence that the spot was the debris left from the collision of a small body, like a comet or asteroid, with Jupiter. Precisely 15 years before (July 16-22, 1994), Jupiter was hit by several fragments of the Comet Shoemaker-Levy 9, which created similar dark spots. As of yet, we don't know what the impacting body was, how big it was, or where it came from. We may never know. But detecting this impact and future impacts is crucial to helping to determine the rate of impacts on Solar System objects.
  • The longest total solar eclipse of the century. Today (right now, in fact), the sun is being eclipsed by the moon over India, Nepal, Bhutan, Bangledesh, China, and the Eastern Pacific Ocean. During a total eclipse, the Moon completely covers the disk of the sun as seen from a narrow path on the Earth. The length of the Moon's covering of the sun depends on geometry, including how close the Moon is to the Earth. Since the Moon's orbit is elliptical, it is closer to the Earth at some eclipses and further away for others. In fact, if the Moon is near its furthest point, it will fail to completely cover the sun, and observers see a ring around the sun (called an "annular eclipse"). For this eclipse, the moon was at its closest point to the Earth just 6 hours before the eclipse! At the point of greatest eclipse, totality will last 6 minutes and 39 seconds. Be sure to use Google tomorrow to find some neat pictures of the eclipse. Those of us waiting for the next total eclipse in the continental USA still have another 8 years to wait.
  • Hubble is coming along nicely. A nice, detailed report from the Hubble Servicing Team shows that commissioning of the repaired instruments is going well and nearly finished, with the exception of the repaired Space Telescope Imaging Spectrograph (STIS). It's having major memory problems. I presume the engineers will find their way around that issue, though it may take a while.
  • The Thirty Meter Telescope finds a home. The Thirty Meter Telescope (TMT) Corporation, a collaboration including the Association of Canadian Universities for Research in Astronomy, the University of California, and the California Institute of Technology, announced today that they will build what would be the world's largest telescope at the summit of Mauna Kea on the island of Hawai'i. The site selection allows the telescope to move from planning phases into construction. Mauna Kea, according to the TMT, is the best site available, and it also ensures that the TMT will be the only next-generation large telescope able to view the skies of the northern hemisphere. There are cultural and environmental challenges to building on Mauna Kea, but it is possible to build in a culturally- and environmentally-friendly way.

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