Science File / An exploration of issues and trends affecting science, medicine and the environment.

The space station Mir, with shuttle Atlantis attached, will be visible as a very bright “star” tonight (9:27 p.m.). Saturday (9:12) and Sunday as it passes 250 miles above the Earth. On Sunday it moves between the Moon and Mars at 9:56 p.m. and two minutes later disappears into the Earth’s shadow. White crosses show the spacecraft’s path at 30- second intervals. Source: John Mosley, Griffith Observatory