There may be an Earth-like planet one solar system away (Updated)
Update 8/24/16: The original story has been confirmed and details have been released. The planet, currently called “Proxima Centauri b,” orbits its sun in 11.2 days. Astronomers believe that it is rocky, and roughly 1.3 times as large as the Earth.
Perhaps most significantly, the planet is tidally locked like our moon, meaning one side always faces its star. Proxima Centauri is .15-percent as bright as the sun, which means the planet wouldn’t necessarily be scorched, but the temperature difference between the two sides may be extreme. It might also make it more difficult to have an atmosphere and water. It is in the sweet spot though – the planet is about as far from its star as the Earth is from the sun.
The planet is currently nicknamed “Pale Red Dot,” referring to what astronomers believe it looks like. The prevailing theory is that it the side facing the sun is dark red. If there is an atmosphere, it would likely make the sky purple and orange, and any vegetation would theoretically be crimson rather than green (assuming vegetation on the planet obeys the same rules as on Earth).
There is also a concern that Proxima Centauri bombarded the planet with radiation during its formation. If so, that radiation may have burned off any atmosphere and water. If the planet formed further away though, it may have survived the radiation unscathed. At the moment, one of the only ways to tell if there is an atmosphere is if the planet passes directly in front of Proxima Centauri in what astronomers refer to as “transit.” The position of the star makes this unlikely though; there is only a 1.5-percent chance of us seeing this.
For now, more research is called for. Sending a probe or another form of spacecraft to the planet would take decades and possibly generations of astronomers. Within the next few decades, there will be more telescopes created with increased power. With luck, within two decades or so we may be able to see the planet with enough clarity that we could see continents (if there are any). At the moment, however, that is still just theoretical.
This planet will receive a lot of attention over the coming years. It’s not just the closest possibly habitable planet discovered to date, it is the closest potentially habitable planet we will ever discover. Proxima Centauri is the closest star to Earth, making this planet the closest to Earth. That also makes it the most likely target for our first interstellar trip, whenever that may be.
Original story 8/16/16: With the Kepler spacecraft constantly sending us back evidence new planets all the time, it can be a little easy to take it for granted when there is news of another one being discovered. There have been hundreds already, but this one isn’t like all the others.
A new, as yet unconfirmed report from the German newspaper Der Spiegel claims that the European Southern Observatory (ESO) has found an Earth-like planet orbiting the star Proxima Centauri within the Goldilocks zone, meaning it could potentially harbor life. That would put it in the company of dozens of other potential planets astronomers have discovered, but what sets this one apart is the proximity to Earth.
Proxima Centauri is the nearest star to our own sun, making it our closest neighbor in the galaxy.
To add fuel to the rumors, the ESO has not denied the planet’s existence. Instead, ESO spokesman Richard Hook said: “We are not making any comment.” It’s always dangerous to make assumptions based on non-statements, but there is a good reason for the ESO to remain tight-lipped. Part of its hesitancy may be due to a previous announcement it made in 2012, when it claimed to have discovered a planet named Alpha Centauri Bb, which would have made it the closest known planet to Earth in another solar system. The findings proved to be false though, and the observatory was forced to retract its claim.
As a result, the ESO may simply be acting cautiously. According to Der Spiegel, its anonymous source claimed the ESO is moving as quickly as it can.
Proxima Centauri is an M-type red dwarf star located 4.2 light years from Earth. It circles Alpha Centauri A and B on a 500,000 year orbit; in 27,000 years it will cede the title of closest star to Earth, then regain it several hundred thousand years later.
In the late 80s, NASA and the US Naval Academy worked on “Project Longshot,” a mission that would, in theory, reach Alpha Centauri in 100 years. To do that though, it would need to travel at 13411 km/s, roughly 4.5-percent the speed of light, or roughly 30 million mph. The plan was to use a fusion reactor to power the engine. The project was eventually scrapped as the technology wasn’t quite there yet and the costs to develop it, plus the risks involved, shelved the mission before it got off the drawing board.
If we hope to reach Proxima Centauri, we still have a long way to go – the New Horizon mission to Pluto hit a top speed of around 36,400 mph – but it is conceivable that within the next few decades we will have the technology to reach our next door neighbor in the galaxy within the course of a lifetime (or maybe two).
If the planet around Proxima Centauri is confirmed to be Earth-like and within the Goldilocks zone, expect a lot of astronomers to turn their attention to the discovery as they attempt to discern its size, possible makeup, and where exactly it is within the zone – if it is too close or too far, even within the zone, the chances of it being Earth-like drop significantly.
So for now, we wait for an official word (or maybe official denial). When/if it comes, expect Proxima Centauri to jump to the top of the “most wanted” destinations list for astronomers.