Space · Mercury
The closest planet to the Sun — temperatures, craters, and wild day lengths.
Space / Mercury
Closest planet to the Sun — heat, ice craters, and super-long days.
88 days
Year length
800°F
Daytime high
-290°F
Nighttime low
1st
Planet from the Sun
The basics
Mercury is the smallest planet and the closest to the Sun — a cratered world with almost no atmosphere and wild temperature swings.
Extremes
With almost no air to trap heat, Mercury’s day side can roast near 800°F while the night side plunges toward -290°F.
Ice?
Yes — in permanently shadowed polar craters, water ice can survive despite Mercury’s reputation as a furnace.
No — Venus is hotter overall because of its thick atmosphere. Mercury has the wildest day/night swings.
Keep exploring
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