Trivia

Hard

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

J
X
H
Y

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

Electronic Resistors Are Commonly Distinguished With What Markings?

Trivia

Hard

In 1981 It Would Take You Two Hours To Download What?

Trivia

Hard

Google Has Leveraged Security Captcha To Successfully Do What?

Trivia

Very Hard

The First High Definition Movie Pirated Was?

Trivia

Hard

Space Sickness Is Measured In What Units?

Trivia

Hard

The Colors Of The Rainbow Were Identified And Set As They Are Now By?

Trivia

Very Hard

The Odd And Rigid Positioning Of The Arms Often Seen After A Concussion Is Called The?

Trivia

Hard

Who Was The Only U.S. President To Hold A Patent?

Trivia

Hard

In An Effort To Cull The Out-Of-Control Rabbit Population, The Australian Government Turned To?

Trivia

Hard

The Water Jets Under The Space Shuttle Launch Pad Aren’t For Cooling, But?