The popular radio spot "Earth & Sky" sets up a booth at the National Air and Space Museum March 14-16 to record visitors' science questions. Yours could be chosen to air on stations nationwide. Washington is "Earth & Sky's" first stop on a three-city tour this year. Its miniature recording studio will be open between 10 a.m. and 5 p.m. on all three days.

While the daily 90-second program handles all aspects of science, roughly one-third of the shows are devoted to astronomy and space.

"Earth & Sky" can be heard each weekday at 8:59 a.m. on WETA-FM (90.9). Last year the tour produced about 675 questions, of which 75 will be used on the air.

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Saturn perches just above the left shoulder of the constellation Orion. The ringed planet is very high in the sky, nearly 70 degrees above the southern horizon, at sunset early in the month. You can see its wide rings facing us when using a telescope or binoculars. Saturn is a bright object at zero magnitude and it's visible from the city and suburbs. Now throughout the night it treks across the southern sky, toward the west, where it sets at about 2 a.m.

Jupiter also is visible at sunset. The giant ball of gas is found in the heart of the constellation Cancer, in the eastern sky. By 8 p.m. it can be easily spotted in the southeast, and at midnight can be found in the southwest. At negative second magnitude this planet is very bright. But beware nightfall on the Ides of March, as the waxing gibbous moon makes close acquaintance with Jupiter.

In the hours before dawn, the heavens now feature Mars ascending the east-southeast sky around 3 a.m. At first magnitude -- which makes it dimmer than Saturn or Jupiter -- it is possible to find the reddish Mars above the teapot shape of Sagittarius.

Venus remains a morning beauty. The planet rises before 5 a.m. now, and just before sunrise it can found about 20 degrees above the southeastern horizon. It is not hard to be charmed by this planet because it reflects so much sunlight, and it measures an ultra-bright negative fourth magnitude.

And, let's give a nice warm welcome to the sun. As it appears to cross the equator officially at 8 p.m. EST, on March 20, spring sends winter away during an astronomical event called the vernal equinox, according to the U.S. Naval Observatory.

Down-to-Earth Events

March 1 -- Charles Bennett, of NASA's Goddard Space Flight Center in Greenbelt, unveils his full-sky map, based on cosmic microwave background radiation. At the regular meeting of the National Capital Astronomers, held at the Montgomery County Bethesda-Chevy Chase Regional Center, 4805 Edgemoor Lane, next to the Bethesda Metro station. 3 p.m. Information,

March 5 -- Blooming with star and planet information, astronomer Elizabeth Warner talks about "The Spring Sky." At the University of Maryland's observatory on Metzerott Road, across from the System Administration building in College Park. View the late winter heavens through a telescope after the talk. 8 p.m. Information, 301-405-6555;

March 6 -- After examining the Martian terrain, Ken Edgett, a geologist at Malin Space Science Systems, unravels the planet's complex and rocky past in his talk, "Postcards From Mars." At the Einstein Planetarium, National Air and Space Museum. 7:30 p.m. Information, 202-357-2700;

March 9 -- Can you expect clear skies for observing? Astronomer Bob Bunge explains how to use digital weather forecasts to predict astronomical observation-site conditions. At the regular meeting of the Northern Virginia Astronomy Club, Enterprise Hall (Room 80, on the basement level), George Mason University in Fairfax. Use parking lot B. 7 p.m. Infomation,

March 18 -- It's been almost three decades since the last Apollo mission to the moon, and astronauts Eugene A. Cernan and Harrison H. "Jack" Schmitt reflect on that exciting trip at 8 p.m. in the Lockheed Martin Imax Theater, National Air and Space Museum. While admission is free, tickets are required. They are available at the theater box office, or at (a small service charge will apply). also can be called at 800-529-2440.

March 20 -- Astronomer Suchitra Balachandran discusses the makeup of the stars and what it tells us. The talk will be at the University of Maryland's observatory in College Park. 8 p.m. Information, 301-405-6555;

March 25 -- Black hole collisions and big bangs create real wrinkles in time. Physicist Kip Thorn, of the California Institute of Technology, shows how scientists gain a better understanding of the cosmos in his talk, "Probing the Universe With Gravitational Waves." At the auditorium of the Carnegie Institution of Washington, 1530 P St. NW. 6:30 p.m. Information, 202-328-6988.

March 29 -- Historian David DeVorkin discusses the great achievements of women astronomers in his talk "Women Who Changed the Universe." At the Einstein Planetarium, National Air and Space Museum. 6 p.m. Information, 202-357-2700;

Blaine Friedlander can be reached at