Scientists Say: Proxima b

The star closest to our sun isn’t alone

Proxima b

This is an artist’s idea of what it would be like to stand on Proxima b.


Proxima b  (noun, “PROX-ih-mah BEE”)

This is the shortened name for Proxima centauri b. It’s a newly-discovered planet. Scientists found it orbiting the star Proxima centauri, our nearest stellar neighbor. Proxima centauri and Proxima b are only 4.2 light-years away.

Proxima b has its boring name because that’s how the International Astronomical Union (IAU) labels planets. A new planet is first named for its star — in this case, Proxima centauri. Then it gets a lower-case letter. The first planet is always “b,” followed by “c,” “d” and so on. The letters are given in the order the planets are discovered. Planets can also be named after the telescopes that spotted them.

People can ask for popular names to use for planets, in addition to their official names. For example, a group might put together a petition to name the planet after a famous scientist or a mythological figure. But the IAU has special rules for planet names. No one can name a planet after a pet (sorry, Fido). No political, military or religious figures (sorry, Ceasar). No one can name a planet after someone who is alive (sorry, Bill Nye). Commercial products are not allowed — so no planet Coca-Cola. And the name also has to be free for public use — so Captain Kirk is out. With all of those rules, Proxima b will just have to do.

In a sentence

Proxima b is close enough to its star that water could exist there as a liquid — meaning this could be a good place on which to hunt for alien life.

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

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