We may have finally found Earth’s replacement.
In an announcement made this week in the journal Astronomy and Astrophysics, scientists hailed Ross 128 as a planet that’s a little bigger and heavier than Earth, orbiting a star that’s smaller and dimmer than our own. That means it likely basks in solar radiation that’s only a little stronger than what we’re used to here on Earth. More importantly, it lies in that rare stretch of space known as the "Goldilocks zone" — where it’s just warm enough for water to exist. It may even have an atmosphere.
The best part? It's just hop, skip and an 11 light-year jump away. While hurtling through space for 11 years at the speed of light may sound like a daunting proposition, when you look at other top candidates for replacing Earth, that’s pretty much right next door. In fact, it’s the second closest exoplanet, a term used to describe any world outside our solar system.
And the closest exoplanet, Proxima b, doesn’t exactly instill us with confidence about supporting any kind of life. While Proxima b may lie in the so-called habitable zone of its host star — a red dwarf called Proxima Centauri — the planet gets scorched regularly by solar flares from that ornery sun.
In fact, a year after Proxima b’s discovery, scientists still can’t figure out if it might be a nice place to raise the kids — or a burning slag of radioactive hell.
Ross 128 b also orbits a red dwarf, but one considerably less prone to fiery outbursts.
"Just because Proxima Centauri blasts its planet with strong flares and high energy radiation, yes, I think Ross 128 is much more comfortable for the development of life," co-discoverer Nicola Astudillo-Defru from the Geneva Observatory in Switzerland, tells BBC News.
Kepler-10b, another recently discovered planet, may be a stellar example of what happens when you get too much sun. In this rendering from a NASA artist, it's burnt to a molten crisp. (Photo: Dana Berry/NASA)
Certainly not being a lake of fire is a step in the right direction. But Ross 128 b will need more than that to sustain life as we know it.
"We still need to know what the atmosphere of Ross 128 b is like," Astudillo-Defru adds. "Depending on its composition and the reflectivity of its clouds, the exoplanet may be life friendly with liquid water as the Earth, or sterile like Venus."
Puzzling out the planet’s characteristics will be slow going, as a much-needed ultra-powerful telescope won't be online until 2024. In fact, it took the research team more than a decade of scanning the region just to catch a hint of its existence. For that, they relied on an instrument called the High Accuracy Radial Velocity Planet Searcher (Harps) in the Chilean desert. And technically, it wasn't so much a glimpse of the planet that caught their attention, but a wobble.
The five-nation scientific team focused on the red dwarf, looking for the telltale profile of an orbiting planet: essentially, a faint wobble caused by the star's gravitational yank.
If it took more than 10 years to detect Ross 128's mere existence, you might imagine how far we are from actually getting space boots on the ground — 11-light-year hike or not.
In other words, there’s no need to hail a cab to your local space station just yet. Our time might be better spent working on the light-speed engine that could take us there in a brisk 11 years or so.
Or, even better, we could spend that time making our own planet the kind of place that doesn't require a backup.