If the skies ever clear, residents of central Maryland will have five opportunities -- two of them tonight -- to watch the space shuttle Atlantis and the Russian space station Mir as they fly over the region.
Unfortunately, the weather forecast calls for cloudy, humid weather to continue through Sunday, with scattered showers and thunderstorms each day.
The 122-foot shuttle was scheduled to dock with the 100-foot Mir at 9 a.m. EDT today, 245 miles above central Asia. Together, they will form the largest, brightest man-made object ever to fly in space.
With clear skies, the combined craft should appear as a single bright star moving slowly across the sky shortly after sunset. That's when skies are dark but sunlight still reflects off the spacecraft, making them visible from the ground.
NASA has supplied the dates and times for sightings from the Baltimore area. Elevations are a measure of the distance above the horizon. The horizon is at zero degrees; halfway up the sky is 45 degrees. Ninety degrees is directly overhead.
* Tonight at 9:21 p.m. EDT -- Atlantis/Mir should be visible for four minutes. It should appear at a spot 22 degrees above the horizon in the north-northwest and move to a place 15 degrees above the eastern horizon.
* Tonight at 10:57 p.m. EDT (on the next orbit) -- The combined craft will be visible for one minute. It will appear 15 degrees above the western horizon and move to a place 23 degrees above the west southwest before disappearing.
* Tomorrow at 10:02 p.m. EDT -- It will be visible for three minutes, appearing 24 degrees above the west-northwest horizon and crossing to a spot 27 degrees above the south-southeast. Its maximum elevation will be 54 degrees -- the highest for Baltimore during this flight.
* Saturday at 9:09 p.m. EDT -- Visible for two minutes, the spacecraft will appear at its maximum elevation of 41 degrees above the east-southeast. It will then move down toward the horizon, disappearing into shadow 15 degrees above the east-southeast.
* Sunday at 9:48 p.m. -- The craft should be visible for four minutes and reach a maximum elevation of 23 degrees above the horizon. It will appear 15 degrees above the western horizon and cross to a spot 15 degrees above the southern horizon before disappearing.