Instant Guide

NASA's search for another Earth narrows: Meet our closest twin yet

Meet KOI 172.02 — a potentially wet exoplanet just a tiny bit bigger than our own

Seventeen billion. That's how many Earth-sized planets exist in our Milky Way galaxy, according to new estimates from NASA. That's enough for every man, woman, and child alive to have at least two planets to call his or her own.

The revelation is why scientists who are part of NASA's Kepler mission — charged with scouting new alien worlds — are suddenly so enthusiastic about the odds of finding Earth's twin. At the meeting of the American Astronomical Society earlier this week, the Kepler team named 461 new candidates to add to its ongoing tally of 2,740 potential "New Earths" inside what's called the Habitable Zone, a just-right distance from a planet's respective star. In theory, planets within this "Goldilocks zone" could have similar surface temperatures and climate conditions conducive to liquid water, and perhaps — a big perhaps — even support life.

Scientists have now zeroed in on the most Earth-like of Earth-like exoplanets to date. KOI 172.02 (Kepler Object of Interest — yeah, it's a mouthful) is just a tiny bit larger than our own "Blue Marble," with a diameter 1.5 times our planet's. Its orbit is really close to Earth's own calendar year, as it takes just 242 days to circle its star. Space.com has a neat infographic comparing the two.

KOI 172.02 leapfrogs to the front of the pack of potential Earth twinsies, which includes one-time frontrunner Gliese 581g (20 light-years away) and Gliese 667Cc (which lives in a triple-star solar system).

Recommended

YouTuber on wilderness expedition discovers new species of tarantula
A bamboo forest.
that's no panda

YouTuber on wilderness expedition discovers new species of tarantula

Webb telescope in position beyond the moon
James Webb Space Telescope
floating in the most peculiar way

Webb telescope in position beyond the moon

Our war with natural selection
A COVID patient.
Picture of William FalkWilliam Falk

Our war with natural selection

Boosters provide robust protection against Omicron, per studies
COVID-19 vaccine.
booster boost

Boosters provide robust protection against Omicron, per studies

Most Popular

Senate candidate J.D. Vance says 'our country's kind of a joke'
J.D. Vance
ba dum tssss

Senate candidate J.D. Vance says 'our country's kind of a joke'

Stephen Colbert's Late Show ropes Peppa Pig into Peloton's dead TV character mess
Peppa Pig
'Daddy Pig Gets a Peloton'

Stephen Colbert's Late Show ropes Peppa Pig into Peloton's dead TV character mess

Florida advances ban on making white people feel 'discomfort' over past racism
Ron DeSantis
Fragility

Florida advances ban on making white people feel 'discomfort' over past racism