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

NASA spacecraft to collide with asteroid to study planetary defense
DART spacecraft
cosmic crash

NASA spacecraft to collide with asteroid to study planetary defense

NASA's Webb Telescope captures clearest image of Neptune's rings in 30 years
Neptune with rings
Put a ring on it

NASA's Webb Telescope captures clearest image of Neptune's rings in 30 years

WHO chief says COVID's end is 'in sight'
WHO Director-General Tedros Adhanom Ghebreyesus.
cautiously optimistic

WHO chief says COVID's end is 'in sight'

Biden details efforts to end cancer
Biden Cancer Moonshot Address
Cancer Moonshot

Biden details efforts to end cancer

Most Popular

Is Putin's Ukraine 'partial mobilization' the beginning of his end?
Vladimir Putin.
Opinion

Is Putin's Ukraine 'partial mobilization' the beginning of his end?

Hot mic catches South Korean president swearing after talking to Biden
yoon suk yeol photo
potty mouth

Hot mic catches South Korean president swearing after talking to Biden

Mayor of NYC mulls plan to build tent city for influx of migrants
migrant bus photo
Tent City

Mayor of NYC mulls plan to build tent city for influx of migrants