Just after sunset, look for the moon only a few degrees above the western horizon. Because of the glare from sunset, try using binoculars to pick out the lunar sliver, and then scan 7 degrees to its left for star-like Mercury. Observers at lower latitudes—closer to the equator—will be able to catch the cosmic pair higher in the sky, where they're easier to spot.

The comet is famous, of course, because of the European Space Agency’s Rosetta spacecraft that is currently orbiting it. The icy interloper is racing away from the sun at nearly 74,000 miles per hour (120,000 kilometers per hour) and is about halfway between the orbits of Earth and Mars.

The comet is shining feebly, at only magnitude