Skywatchers, especially those in the Chicago area, are in for a treat tonight if the weather is clear. Early Monday, the space shuttle Discovery undocked from the International Space Station to prepare for its return to Earth. On Monday and Tuesday (and depending on where you live) you can see the two spaceships as they fly in tandem with each other. Tonight (Tuesday) will be the last night to see those two as Discovery is scheduled to land in Florida on Wednesday.
In the Chicago area, the best time to see the two spaceships will be at 6:20 p.m. local time. They will be in the north sky flying west to east. Discovery will be the fainter of the two (at a magnitude -1.1) and the space station will be brighter (at -3.4). The reason the ISS is brighter is because it is much bigger.
They will reappear at 7:56 p.m., but will be in the lower southwest sky and will appear fainter.
It is suppose to rain this evening in the Chicago area, but I hope it hold off until later in the night.
This will be the last time to see Discovery as it is retiring after this flight. There are only two more shuttle flights scheduled — Endeavour and Atlantis will each make their final flights this year.
You can check to see the location of the space shuttle or the ISS or any other satellite by going to Heavens Above and input your location.
Enjoy this NASA video taken Monday morning of Discovery performing the fly-around maneuver of the ISS.