Sky Watch

Mercury in the Spotlight

By Blaine P. Friedlander Jr.
Special to The Washington Post
Sunday, October 29, 2006; Page C02

There's a little black spot on the sun Nov. 8.

It's the planet Mercury transiting the sun. You'll need special methods to view it, since you cannot see it with your eye alone. And be warned that it's not safe to look directly at the sun with your naked eye, or through a telescope, binoculars or any other kind of magnifying lens.

What's a transit? It's when Mercury or Venus crosses the sun from our earthly perspective. There are only 13 Mercury transits in a century, and Merc last traversed the sun May 7, 2003. Its next transit is May 9, 2016. Before Venus transited the sun in June 2004, it had last crossed the solar disk in 1882.

The transit starts at 2:12 p.m. and ends at 7:10 p.m., according to Fred Espenak, a NASA Goddard Space Flight Center astronomer who maintains a transit Web site, http://sunearth.gsfc.nasa.gov/eclipse (look for the link to "transits"). Washington area residents will not see the transit end, since the sun sets at 5 p.m.

Once the transit hubbub settles, get up before dawn between Nov. 15 and Thanksgiving to find Mercury in the eastern sky (about zero magnitude, visible with the naked eye).

Safe places to see the Mercury transit:

The University of Maryland at College Park -- The public is invited Nov. 8 to McKeldin Mall, near the Administration Building, from 1:45 to about 4 p.m. Web: http://www.astro.umd.edu .

Montgomery College -- On the roof of the King Street parking garage (Fenton and King streets, at the college's Takoma Park/Silver Spring campus, from 2 to about 5 p.m. Web: http://montgomerycollege.edu/Departments/planet/planet/Mercurytransit2006.html .

The Exploratorium -- San Francisco's Exploratorium will webcast the transit live from the Kitt Peak National Observatory in Kitt Peak, Ariz. The webcast, from 2 to 7:10 p.m., will be at http://www.exploratorium.edu/transit .

Look for the Leonids

The Leonid meteors are expected to peak about midnight Nov. 18-19. Astronomers widely disagree on how many Leonid meteors can be seen in an hour. The meteors appear to emanate from the constellation Leo in the east. Leonid meteors are little dirt particles left in the trail of Comet Temple-Tuttle . As Earth passes through the trail, the dirt strikes our atmosphere and vaporizes, creating those gorgeous streaks.

Down-to-Earth Events

Nov. 3 -- "An evening with Wally Schirra, Gene Cernan and Tom Stafford." Schirra is the only astronaut to have flown on the Mercury, Gemini and Apollo missions. Cernan was the last person to leave footprints on the moon , and Stafford flew on the Apollo-Soyuz mission. At the Lockheed Martin IMAX Theater, National Air and Space Museum. Free, but tickets are required. Ticket information: http://www.nasm.si.edu or 202-633-1000.

Nov. 4 -- The National Park Service and the National Capital Astronomers host "Exploring the Sky" at Rock Creek Park, near the Nature Center, in the field south of Military and Glover roads NW. 7 p.m. Information: http://capitalastronomers.org or 202-895-6070.

Nov. 5 -- Mia Bovill, astronomer, on "The Science of Science Fiction: Wormholes and Warpdrive," at the University of Maryland Observatory open house, College Park. 8 p.m. Web: http://www.astro.umd.edu/openhouse/index.html .

Nov. 11 -- See the splendid fall sky at Sky Meadows State Park, near Paris, Va., from 5 to 11 p.m. Parking fee: $4. Information: 540-592-3556 or http://www.dcr.state.va.us/parks/skymeado.htm .

Nov. 11 -- Neil Gehrels of the NASA Goddard Space Flight Center explains the gamma ray burst discoveries made with the Swift satellite observatory, at the National Capital Astronomers meeting at the University of Maryland Observatory, College Park. 7:30 p.m. Web: http://capitalastronomers.org .

Nov. 20 -- The best of times for studying Mars : Andrew Johnston, National Air and Space Museum geographer, discusses "A Tale of Two Planets: Comparing Earth and Mars" at the University of Maryland Observatory open house, College Park. 8 p.m. Web: http://www.astro.umd.edu/openhouse/index.html .

Blaine Friedlander can be reached at PostSkyWatch@aol.com.

© 2006 The Washington Post Company