What a way to start the official last year of the second millennium: An easy-to-watch total lunar eclipse on the night of Jan. 20-21.

While the sun will be behind us to bathe the full moon in light, Earth cuts into that light and casts its shadow on the lunar surface. To us, Earth's shadow appears to gently roll across the lunar surface that evening and it is perfectly safe to watch because we're not looking at the sun.

"That's the wonderful thing about lunar eclipses: They're 100 percent safe to watch and you don't need a telescope or binoculars," says astronomer Fred Espenak of the NASA/ Goddard Space Flight Center in Greenbelt, and a noted expert on eclipses.

Viewers with the time, patience and clear sky will be rewarded with about 78 minutes of totality.

In the early partial-eclipse phase, the moon starts crossing Earth's shadow, known as the umbra, at about 10:01 p.m. EST on the evening of Jan. 20. At 11:04 p.m., the moon moves into the totality phase, according to Espenak. At about 12:22 a.m., the lunar eclipse once again goes into a partial phase that lasts until about 1:25 a.m. for viewers here.

How this lunar eclipse will appear is anyone's guess. Sometimes the moon becomes so dark it seems invisible, and at other times it turns red or orange. Since there has been no major volcanic activity recently, Espenak predicts the moon will turn a bright red or orange.

Down-to-Earth Events

* Jan. 5--Astronomer Gretchen Walker explains "Cosmic Distances: Just How Far, Far Away Is That Galaxy?" At the University of Maryland astronomy department's open house, at the observatory on Metzerott Road. Sky-watch through a telescope afterward. The observatory is across from the university's system administration building. 8 p.m. Information, 301-405-3001; Web, www.astro.umd.edu/openhouse

* Jan. 8--Live and in person, the cuddly Berenstain Bears stroll around the National Air and Space Museum's new museum shop to promote their book, "The Berenstain Bears on the Moon." Noon-3 p.m. Information, 202-357-2700.

* Jan. 8--Michael A'Hearn of the University of Maryland discusses the Deep Impact mission, a NASA program that will explore a comet nucleus. At the regular meeting of the National Capital Astronomers, at the Lipsett Auditorium in the Clinical Center (Building 10) of the National Institutes of Health. 7:30 p.m. Web, www.capitalastronomers.org

* Jan. 9--The Northern Virginia Astronomy Club meets in Lecture Hall 1 on the campus of George Mason University in Fairfax. 6 p.m. Park in lots F and G.

* Jan. 11--More than a dozen of the National Air and Space Museum's curators and photographers will sign copies of their books at the grand opening of the museum's new gift and book shop. 1:30-3 p.m.

* Jan. 15--The Cat in the Hat in person at the National Air and Space Museum's shop: The famous feline will promote his new book, "There Is No Place Like Space," and will prowl the shop from noon until 3 p.m.

* Jan. 20--The University of Maryland's astronomy department presents the video "From Earth to the Moon" at its observatory open house on Metzerott Road, 8 p.m. Then, join astronomers at the College Park campus' Hornbake Plaza to watch the lunar eclipse from 10 p.m. to 1:30 a.m. (Permit-free parking in the Regents Drive garage.) Information, 301-405-3001.

* Jan. 22--Sally Ride, the first American woman in space, provides a short lecture at the National Air and Space Museum's Einstein Planetarium, followed by a book signing at the new Museum Shop there. Ride's book, "The Mystery of Mars," was written for children and gives a history of Mars exploration. Lecture, 11 a.m.; book-signing, 12:30-2:30 p.m.

* Jan. 29--Harold Geller of George Mason University discusses the odds of comets, asteroids and meteors striking Earth. Einstein Planetarium, National Air and Space Museum. 6 p.m.

* Jan. 29--Learn how astronomers of long ago used astrolabes to calculate heavenly movements, at the Montgomery College Planetarium in Takoma Park. Parking in the faculty lot. 7 p.m. Information, 301-650-1463; Web, www.mc.cc.md.us/ Departments/planet

* 2000 Space Fiction Film Series--The National Air and Space Museum presents films each Friday at its Langley Theater this month. "E.T. the Extra-Terrestrial," Jan. 7; "Star Trek--Insurrection," Jan. 14; "Men in Black," Jan. 21, and "The Abyss" (Special Edition), Jan. 28. Single tickets, $3; series ticket, $10. Tickets may be purchased in advance through Protix, 800-529-2440, or www.protix.com