Trivia

Hard

Which Letter Appears Once a Year on the Moon’s Surface?

X
Y
H
J

Answer: X

The human mind is a pattern seeking one.  We humans are quite good at turning abstract shapes into familiar ones.  One of the most famous astronomical examples of this is the Man in the Moon–from our terrestrial vantage point the craters on the Moon’s surface look like a man’s face looking down on us.

If you look even closer at the Moon, however, you will find a much tinier surface feature just waiting for us to visualize a symbol over it.  For a scarce four hours at the beginning of the first quarter, the horizon of the Moon is illuminated by the Sun in just such a way that the walls of the lunar craters La Caille, Banchinus, and Purbach cast shadows that create the illusion of a giant X on the surface of the Moon. This formation is known as the Purbach Cross (thanks to the related crater) or the Werner X (named so after the Werner crater, a sizable landmark just south of the X formation).

Bonus Trivia: Formations like the Purbach Cross are known as clair-obscur formations, or light-dark formations, created by extreme contrast between natural light (in this case the sun) and darkness (the deep darkness of the dark side of the Moon and the Moon’s craters).

Trivia

Easy

Lewis And Clark Expected To Find What Animal On Their Journey West?

Trivia

Hard

Hidden Within The Brooklyn Bridge Are Vaults Originally Used To Store?

Trivia

Hard

The Opposite Of Hibernation Is Called?

Trivia

Hard

Which U.S. State Has The Longest Official Name?

Trivia

Hard

The Rictus Scale, Not To Be Confused With The Richter Scale, Measures What?

Trivia

Hard

Alfred Nobel Established the Nobel Prize After What?

Trivia

Very Hard

What Did The Inventor Of The Pet Rock Later Try To Sell Americans Bit By Bit?

Trivia

Hard

What Is The Only NASA Asset Named After A Living Person?

Trivia

Hard

Best Known For Lord Of The Rings And Game Of Thrones, Sean Bean’s Biggest Body Of Work Is Focused On?

Trivia

Easy

Which Of The Following Lake Types Is Formed By A Meandering River?