A NASA photo shows the space shuttle Atlantis against the backdrop of a cloud-covered Earth and the greenish hue of the Aurora Australis, the southern hemisphere's answer to the northern lights. The photo was taken from the International Space Station (ISS) on July 18. The solar panel at the top left of the shot is part of the ISS. The robotic arm seen in the middle of the picture is the space shuttle's 50-foot-long Orbiter Boom Sensor, which was used for the last time today to inspect the shuttle's thermal protection system after it undocked for its final journey home. The robotic arm made its first flight into space on the 1983 shuttle Challenger.