On Thursday, May 29th, Comet 209P/LINEAR will pass just 5 million miles (8 million km) from Earth, one of the closest comet approaches in history.[caption id="attachment_246599" align="alignright
Comet 209P/LINEAR moves rapidly south through the sky around its closest approach on May 29th.[/caption] Just 5 days earlier, early on the morning of May 24th, Earth is predicted to pass through the debris that lines the comet's orbit, causing a new and possibly spectacular meteor shower. But regardless of whether the meteor shower materializes, the comet itself is an appealing target for backyard astronomers.Comets are notoriously unpredictable. But with any luck, this one will shine at 10th magnitude from May 24th through June 2nd, making it an easy target through an 8-inch scope from a typical suburban backyard — or through a much smaller scope under dark skies. But the comet is moving rapidly southward through the sky, so it will be invisible from the Northern Hemisphere toward the end of that period.
At its closest approach, 209P will be moving almost almost a half degree per hour — the field of view of a telescope at medium-high power. So you need very detailed charts to locate it. Select one or more from the list below depending when you plan to observe. The times are plotted in Universal Time, which runs 4 hours ahead of Eastern Daylight Time and 7 hours ahead of Pacific Daylight Time. For example, 10 p.m. May 26th EDT is 2h May 27th Universal Time, so at that time you should look halfway between the ticks labeled 0h and 4h for May 27th.