Exoplanet Discovered Only 4.3 Light-Years Away In Alpha Centauri, Our Closest Neighbor

Artist’s rendering. Accuracy not guaranteed.

Scientists using the HARPS instrument at the European Southern Observatory’s location in Chile have detected the lightest and the closest exoplanet yet while studying the closest star system to our sun, Alpha Centauri. The exoplanet, Alpha Centauri Bb, orbits one of the three stars in the system. The planet has a mass only 1.13 times that of Earth, and it completes an orbit around Alpha Centauri B every 3.2 days. Located only 3.6 million miles from its star (compared to Earth’s distance of 93 million miles away from the sun) the exoplanet is likely a ball of lava with surface temps exceeding 2,200 °F.

The team found the planet by monitoring small wobbles in Alpha Centauri B’s motion caused the gravitational pull of a planet. In this case, ESO was able to detect variations of only 51 centimeters per second (1.8 km/hour), which they say is the speed of a baby crawling. Since they’re scientists, we assume they arrived at that speed analogy after many trial runs of baby races.

This is the smallest variation in star movement we’ve yet been able to measure. In addition, this is the first exoplanet with a mass similar to Earth’s that we’ve discovered orbiting a Sun-like star. Also, holy crap, this is only 4.3 light-years away.

This is Alpha Centauri! Famed and fabled in a thousand science fiction stories. It’s where the Robinson family was supposed to go in “Lost in Space”. It’s where Zefram Cochrane lived in “Star Trek”. It’s where the Fithp came from in Footfall. Because the system is bright and close, and the stars so close to being like our own Sun, they’re an obvious place to put aliens. Plus, you get the exotic locale of a binary star plus the red dwarf thrown in on top. It’s perfect! So I, and a lot of people like me, grew up hoping against hope we’d find a planet around one of these stars someday. And here we are. [Bad Astronomy]

Even though Alpha Centauri Bb is uninhabitable, small planets like this tend to form in groups, meaning we may find more planets orbiting this star. Dibs. We just called dibs.

We shouldn’t start packing our bags just yet. It will take our Voyager 1 probe another 70,000 years to reach the exoplanet. Even with our best current technologies, Greg Laughlin of UC Santa Cruz estimates it would take us 40,000 years to reach it. But look on the bright side; we’re getting our broadcasts of Breaking Bad 4.3 years sooner than they are.

[Sources: ESO, Bad Astronomy, Ars Technica, IEEE, Blastr]