Avoid the Light - do Globe at Night

Every year, the Globe at Night project asks people around the world to get outside and observe the constellation Orion. Report your location and which of the charts best matches what you saw.

This is a great slacker project. It doesn’t take much time or any tools. You can do it with kids, friends, or whoever. If you forget to do it tonight, you can do it tomorrow or the next time you have clear or mostly clear skies. You have until March 8, 2008 - next Saturday. This is a worldwide project.

To participate, go to the web site and check out the limiting magnitude charts to know roughly what the differences are in what you can see. Then go outside and block the most glaring lights. Let your eyes adjust to the dark for a few minutes as you locate Orion. Carefully consider what details you see in the constellation. Only Betelgeuse - the red shoulder star? All three belt stars? Stars close below the belt? The feet and shoulders? The head cluster? The Orion nebula? Fainter stars below the lower shoulder? Remember the faintest stars you could see.

By the way, Mars is the “extra star” somewhat nearby rivaling Betelgeuse with its bright red color.

Then go inside and report your observation. You’ll need to know where you are, what time you made your observation, and which chart most closely matches what you saw. In 2007, there were 8,491 observations. After a week of observations this year, it looks like there are fewer than 2000 observations.

Viewing more of Mercury

NASA’s Messenger spacecraft flew close by Mercury on 14 January 2008. Of course, it was taking pictures and managed to give scientists views of areas of the planet not imaged when Mariner 10 flew by in 1974 and 1975. Check out this detailed image of a pockmarked Mercury. This page has links to more pictures. The flyby is described here.

This was the Messenger spacecraft’s first of three 200km high fly-bys of Mercury. The next will be October 6, 2008, and the third will be September 29, 2009. Each fly-by slows the spacecraft as it heads to orbiting Mercury in March 2011.

Asteroid Advisory Not Issued for Mars

Scientists on neighboring Earth have not issued an asteroid advisory for Mars on 30 January 2008. An asteroid advisory would mean that an asteroid impact is possible within the next 100 sols. It is issued planet-wide because an impact may have planetary effects. However, the Torino Impact Hazard Scale seems to be Earth-centric.

In this case, a level 4 advisory would be issued at this time for asteroid 2007 WD5. Current calculations indicate a 1-in-75 chance that the asteroid will impact Mars around 10:55 UT on 30 January 2008 (all times Earth-based).

Earth scientists blame light from Earth’s Moon for impeding their observations of 2007 WD5. By early January 2008, they hope to have additional observations that will further refine the asteroid’s path. If Earth had an observatory on the far side of the Moon, maybe these calculations would take place in a more timely manner.

2007 WD5 passed by Earth in early November 2007 and was discovered on 20 November 2007 by the Catalina Sky Survey. It is estimated to be about 50 meters across.

Although the center of the asteroid’s predicted path appears to miss Mars by 50,000 km, that path’s uncertainty region is large enough to graze the planet. In comparison, 2007 WD5 missed Earth by 7.5 million km.

Earth scientists believe that the over-achieving Earth spacecraft that are on Mars are not in danger. MER Opportunity is near, but not in, the possible impact zone.

For further details, pictures, orbital animations, and updates refer to the NASA JPL’s Near Earth Object Program including this report on 21 December 2007.