Solved cryptogram
Mercury has almost no air, so its surface swings between blazing heat and a deep, bitter cold.
Astronomy Facts, sourced to NASA.
What it means
An atmosphere acts as a blanket and a buffer, moving heat from the sunlit side to the dark one and slowing how fast a surface can cool. Mercury has essentially none, so the day side bakes and the night side dumps its heat straight to space. The swing from one extreme to the other is several hundred degrees, which is wider than on any other planet in the solar system.
The claim comes from NASA, and the page it comes from was read on 2026-08-27 to confirm it still says this.
This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.
Solve it yourself
This fact is a cryptogram here: 75 letters over 21 different ones, graded medium.
- SourceNASA
- CollectionAstronomy Facts
- Difficultymedium
- Length75 letters, 21 of them different
Nearby in the collection
The facts either side of this one.
- Royal Society of Chemistryhard, 72 letters
- NASAhard, 74 letters
- NASAmedium, 76 letters
- NASAmedium, 75 letters
About as hard as this one
Scored closest to it by the model behind our guide to solving cryptograms.