Mercury is the smallest planet in the Solar System, and the first planet from the Sun. Its tenuous atmosphere can’t trap the Sun’s heat, so days are fiery at over 400°C, and icy nights drop to nearly -200°C. If you were to stand on the line of shadow separating day and night, you would simultaneously burn and freeze to death.
From our perspective, Mercury is void of any interesting surface details.It’s a tough planet to spot with binoculars, but once you locate it, it’s quite unmistakable.
The shadow line separating day and night makes itself visible as a phase – just like the Moon, Mercury can be seen as a crescent, a semicircle, or a gibbous planet. The phases are notoriously difficult to see with binoculars (and even telescopes), so stock up on patience before you attempt it!
Unfortunately Mercury’s cratered surface can’t be picked up by binoculars. It is far too small, and our atmosphere blurs the details out.
The best time to spot Mercury is roughly half an hour after sunset or before sunrise. Point your binoculars just above and to the left of where the Sun is, and try to make out a bright speck. Make sure the Sun is below the horizon when you look for Mercury, and do NOT look for it during the day. UV rays from the Sun are extremely damaging to eyes, and binocular lenses focus these rays onto your eyeballs. You will burn your retinas.
To find Mercury’s exact rising times, visit timeanddate.com/astronomy/night/. You’ll also find tips on how best to observe it.
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