The good news: Proxima Centauri is so close that it should be relatively easier to start probing these questions.
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It is now the primary target for Russian billionaire Yuri Milner’s ambitious 100 million dollar (£75m) plan to send a fleet of miniature interstellar probes fitted with cameras on a 20-year mission to search for alien life.
More imaginative methods will have to be developed before even a one-way trip to Proxima b lasting less than a human lifetime is possible.
Proxima Centauri is a low-mass red dwarf star, known as an M-class dwarf, that happens to be close to the bright binary star Alpha Centauri AB, which outshines its cool stepbrother, so to speak.
An worldwide team of scientists say changes in the color of the light coming from the planet’s host star suggests Proxima b is a little bigger than Earth – and much closer to its star than we are to the Sun. This planet also provides hope of finding life beyond Earth, as it possibly contains the essentials for life. It’s likely that it formed further out from the star before migrating in, and may have picked up a lot of icy material.
If life were on this planet, it probably survived either underground or deep within its hypothetical oceans, Kaltenegger said.
Proxima b is a rocky, terrestrial planet with a surface – unlike a gas giant, such as Jupiter – that is 1.3 times the size of Earth and orbits its star every 11.2 days.
“We shouldn’t over-play the radiation too much”, he said.
That puts the planet far closer to its parent star than Earth orbits the sun. When the star is pulled slightly away from us, the light is stretched, making it redder.
“The radiation is not going to preclude the existence of life”.
For life as we know it, liquid water is an essential ingredient.
He added that the planet appeared to have a “normal” orbit – not a highly eccentric one, like that of a comet, which would not be conducive to life.
Observers discovered the planet by watching the star wobble.
It’s obviously not possible with current tech to load up an astronaut crew and shoot ’em off for Proxima b, but that doesn’t mean we have no options when it comes to exploration. Hugh Jones, another of the report’s coauthors, said that initial observations of Proxima b were made more than 15 years ago. “This will be the most accessible, closest planet in the habitable zone to our solar system”. And it’s just the right distance from its star that it would be warm enough for liquid water to pool on the surface, assuming the planet has an atmosphere. So we’re probably still around 50 years from getting a probe to Proxima b.
It took years to find the planet.
Magnetic fields and an atmosphere offer a planet some protection.
“We will celebrate this important discovery within the Starshot team”. A paper published by a team of 31 global researchers in Nature says that the planet, Proxima b, is located approximately 4.2 light-years (40 trillion kilometres) from the Earth and has “some characteristics similar” to it.
There are 9 trillion kilometres in a light year.
The aim was to launch the “nanocraft” towards Proxima Centauri within the next two to three decades.
How long would it take to get to Proxima Centauri?
And Proxima b looks a lot like Earth.
“The lifetime of Proxima is several trillion years, nearly a thousand times longer than the remaining lifetime of the Sun”, he said.
Explaining the importance of the discovery, Avi Loeb of the Harvard-Smithsonian Center for Astrophysics, said: “A habitable, rocky planet around Proxima would be the most natural location to where our civilization could aspire to move after the sun will die, five billion years from now”.
“It would open the way to absolutely fabulous new work”, said Prof Nelson.
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If the planet can be spotted crossing or “transiting” the face of its star, astronomers may be able to look for chemical signatures of life by studying the light filtering through its atmosphere.
