Astronomers have found two new planets that could potentially support life
Astronomers have pinpointed two planets orbiting a nearby star that meet pretty much every requirement for supporting life.
They’re almost exactly the same mass as the Earth, they are billions of years old (which means life could have had time to evolve), and they’re orbiting their star at a distance that would support things like water flow and habitable temperatures.
The two planets orbit Teegarden’s star, an ancient star that is only 12-light-years away from the Earth. (“Only” is relative — 12 light-years is equal to 70,540,000,000,000 miles.)
Research on the planets and their sun, published in the journal Astronomy and Astrophysics, reveals Teegarden’s star seems to be stable, without large solar flares or other violent activity that could threaten the potential for life on the two promising candidates.
If the estimated orbit and rotation speeds are accurate, and there are no unexpected factors in the solar system to disrupt astronomers’ other calculations, Teegarden’s two planets could host rocky environments and flowing, puddling water. However, all of these assumptions are estimates, and not actually firsthand observations — for now.
The Teegarden planet discoveries are part of a larger effort by astronomers to locate potentially life-supporting planets in order to refine observation and research technology, like high-powered telescopes, to learn even more about them.
Planets: Teegarden’s Star b and c
Discovered by: An international team of astronomers using the CARMENES spectrographic instrument at the Calar Alto Observatory in Spain.
Date: June 12, 2019
Key facts: Two new planets were detected orbiting Teegarden’s Star, an ultracool, red dwarf less than 13 light-years away. At a minimum, the new planets both weigh in at about 1.1 times the mass of Earth.
Details: These planets, among the “lightest”, found so far in orbit around other stars, were detected using the wobble method – watching for subtle motions in the star as orbiting planets tug them one way, then another.
The star itself could be 8 to 10 billion years old, or roughly twice the age of our Sun.
Although the heft of the two planets is comparable to Earth’s, their other characteristics are unknown. Planet b, which completes one orbit around the star (a “year”) in just under five days, might be habitable despite its close proximity to its star. But Planet c, with an orbit of about 11-1/2 days, falls “comfortably” within the star’s habitable zone, or the distance from the star that could allow liquid water on the planet’s surface.
What’s next: These planets might be prime targets for future follow-up with the next generation of large, ground-based telescopes, which could reveal more of their properties.
The news: Researchers at the University of Göttingen have been studying a star known as “Teegarden’s star” for the last three years. They found two planets orbiting it that seem to bear some similarities to Earth, orbiting in a region where it’s possible there could be liquid water. Their findings are published in the journal Astronomy & Astrophysics this week.
The star: It’s so faint it wasn’t spotted until 2003. It’s one of our closest stars (a mere 12.5 light-years away) and it’s an “M dwarf,” about half as warm as the sun and a tenth as big. That means potentially habitable planets would have to be closer to it than those in our own solar system and thus orbit more quickly. The two new planets were spotted using the CARMENES instrument on a telescope in Spain. It looks for how an exoplanet’s gravitational pull periodically affects a star’s light.
Could they host alien life? The fact the planets bear similarities to our own lump of rock is obviously fascinating. However, there’s no way to know what their atmosphere is like—and so if there could be any life there—until we have more powerful telescopes. “Both Teegarden’s planets are potentially habitable,“ Ignasi Ribas of the Institute of Space Studies of Catalonia told National Geographic. “We will eventually see if they are actually habitable and, perhaps, even inhabited.”