The innermost planet never wanders far from our sun, which means it is usually lost in the sun’s glare and is a consistently challenging observation. This week, however, the tiny world will reach what is known astronomically as its greatest elongation, when it will sit 27 degrees from our home star, equal to the width of three clenched fists held side by side at arm’s width.

To find Mercury, start by using binoculars to look for the faint, starlike world about a half hour after sunset. It will be only five degrees above the western horizon, equal to the width of your three middle fingers held at arm’s length. Jupiter will help you out in your planetary hunt, as the bright