Saturday, November 11, 2006

Mercury Transit


Mercury transits the Sun on November 8. In a previous article, “Shadows and Silhouettes,” we offered information on the upcoming transit, and ideas for getting involved. With less than a week remaining, there’s still time to prepare for a daytime astronomy event with a local amateur astronomy club or set up your computer to log into a webcast of the transit. Mercury transits the Sun 14 times this century. Next Wednesday, you can observe the second transit of Mercury this century, come rain or shine, even if you’re on the dark side of the Earth.

BE SAFE: Mercury is tiny in comparison to the Sun: about 1/195th the apparent diameter of the Sun. You can’t see Mercury without a telescope with magnification of 50x to 100x. The requirements for observing the transit are the same as for simply observing the Sun or photographing an eclipse. Solar filters are required to assure safe viewing. In your search for Mercury, be safe. Don’t look directly at the Sun, and especially don’t look at the Sun through binoculars or telescopes. Permanent damage to your eyesight will result if you do.

How can you get connected? This article is a quick user’s guide to observing the Mercury transit next Wednesday.

For in depth information, go to NASA web pages at Goddard Space Flight Center. Dr. Fred Espenak manages this site on eclipses and transits where you will find a good discussion and details on the upcoming transit of Mercury, and a bibliography for those who wish to dive deeper into the science and history of transits.

For the serious amateur, there’s ALPO, the Association of Lunar and Planetary Observers. John Westfall is the section coordinator for the Mercury/Venus Transit Section of ALPO. He’s written a detailed article describing the upcoming transit with a brief description of the best ways to observe the transit. There are also instructions for how to submit your observations of the transit.

For educators in schools and science centers, there are good lessons on transits and how astronomers will use transits to find extrasolar planets. The NASA Kepler Discovery Mission will seek evidence of other Earths around distant stars by observing transits. You’ll find Kepler Mission classroom activities on planet finding at the mission website. The Astronomical Society of the Pacific’s Educator Newsletter is a further resource. It includes good diagrams and lessons to teach about Mercury and the transit. There’s an extensive set of links to other related sites. There’s an English language version and a Spanish language version.

Amateur astronomers will hold daytime star parties at many sites. You can connect with them by locating your regional club. Many clubs belong to the Night Sky Network, a nationwide community of amateurs who like to share astronomy with the public. You can locate a club near you at the NSN website. Science centers, observatories, planetaria, and astronomy clubs can also be located via Sky and Telescope’s online directory of clubs and community organizations and The Astronomical League’s national directory. Take a look at these resources if you wish to observe the transit with a group in your community.