What is a planet orbiting a star other than the Sun called?
AnswerAn exoplanet
Thousands of exoplanets have been confirmed.
Science · Facts & stats
Alien facts & stats
7 fact-checked facts about astrobiology and the search for alien life, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
Which planet have NASA rovers such as Curiosity and Perseverance explored?
AnswerMars
Both rovers search Mars for signs of past habitability.
Going deeper
What is the 'Goldilocks zone' around a star?
AnswerThe region where liquid water could exist on a planet's surface
It is not too hot and not too cold for liquid water.
What is the famous 1977 radio signal detected by Ohio State's Big Ear telescope called?
AnswerThe Wow! signal
An astronomer circled it and wrote 'Wow!' in the margin.
Which moon of Jupiter is thought to hide a salty ocean beneath its icy crust?
AnswerEuropa
Europa's ocean makes it a top target in the search for life.
Expert level
Which tiny 'water bears' interest astrobiologists because they survive extreme conditions?
AnswerTardigrades
Tardigrades have survived exposure to the vacuum of space.
The 1974 Arecibo message was beamed toward which star cluster?
AnswerM13, in Hercules
The globular cluster M13 is about 25,000 light-years away.
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