Two chances to watch Int'l Space Station
Stargazers will get two opportunities in the coming days (or rather, nights) to watch the International Space Station fly across Baltimore's skies. Both are very bight evening passes, high over head, with plenty of other stuff in the sky to add variety to your time under the stars.
The weather looks pretty good for Saturday night, but Monday evening could be dicey, with "mostly cloudy" skies forecast. Check for weather updates. Urban lighting and thin clouds shouldn't hurt any. The ISS is very bright on these passes.
The first event comes Saturday evening, as the station passes over Lake Michigan and becomes visible from Central Maryland. Look for a very bright, star-like object rising in the northwest at 8:12 p.m. EDT. If it's blinking, has multiple or colored lights, it's an airplane. Keep looking.
The ISS and its crew will climb high overhead, passing just above the moon in the western sky. It will climb as high as 69 degrees - more than two-thirds of the distance between the southwestern horizon and the zenith (straight up) by 8:15 p.m.
From there, the station will pass below the planet Mars in the southeast, disappearing over the Atlantic at 8:17 p.m.
The second pass comes on Monday evening, and it will look very much like Saturday's flyby. The station will rise in the northwest again, this time at 7:26 p.m. EDT. It will pass below the moon, 65 degrees above the southwestern horizon at 7:29 p.m.
From there it will slide off toward the southeast, passing between Mars and Sirius, the bright star to the lower left of the Constellation Orion, before vanishing at about 7:31 p.m. As always, drop back here after the show and share the experience.
Comments
Frank, you have always been very good about alerting us to ISS sightings. Last night, while flying a corporate jet from St. Lucia to Baltimore, we were just south of the NC coastline over the Atlantic at 40,000 feet, we were looking at Venus, the other pilot said to me, what's that star that is moving? It was the ISS! Amazing to see it so clear as it moved toward the eastern horizon. Then, while driving home from BWI, I just happened to see a meteor burning up--it was headed roughly northward over Linthicum. Beautiful greenish glow as it disappeared. What a night!
Posted by: Larry Esser | March 20, 2010 11:12 AM
What a way to celebrate Vernal Equinox 2010. Thanks for the heads-up Frank. A beautiful view from NoVA tonight.
Posted by: hysdavid | March 20, 2010 8:28 PM
Thank you Frank! This is the first night I've been able to take avantage of your ISS alert. What a lovely sight on a very clear first night of spring.
Posted by: Elizabeth | March 20, 2010 8:45 PM
Just a few questions about brilliant visibility of ISS this evening:
Was the ISS in direct sunlight when it crossed over Baltimore just after 8 this evening? It was well after sunset in Baltimore at the time. Was the ISS so high up that the sun was still shining on it? Are the near-sunset and near-sunrise geometries responsible for its brilliance? Put another way, is ISS crossing the Baltimore skies routinely at night, but is not visible because the Sun is no longer shining directly on it?
FR: Yes. The ISS orbits the Earth every 90 minutes. It may be within eyeshot of Baltimore on many of those passes. But it gives off no light of its own. It is only visible when the sky is relatively dark and the station is reflecting direct sunlight. So, in the middle of the night we can't see it because it's in darkness. In daylight we can't see it (or the stars) because our sky is so bright. We see it only in the hours just before sunrise or just after sunset, when the sun is below the horizon for us, but the station - 220 miles up - remains in direct sunlight. Often, we can see the station "vanish" when it passes into the Earth's shadow ("sunset" on the ISS). The station's brightness can also vary depending on the angle of the station's most reflective surfaces, such as its solar panels, relative to the sun and the observer.
Posted by: George Snead | March 20, 2010 11:57 PM