Scientists have discovered a planet that appears to be similar to Earth circling the star closest to the sun, potentially a major step in the quest to find out if life exists elsewhere in the universe, revealed a research published on Wednesday.
The relative proximity of the planet, known as Proxima b, gives scientists a better chance to eventually capture an image of it, to help them establish whether it has an atmosphere and water, which is believed to be necessary for life.
Around 14 percent the size of the sun and about half the temperature, host star of Proxima b, Proxima Centauri is the closest star to our solar system at 4.24 light years or 40 trillion km away.
Future studies may reveal if any atmosphere contains tell-tale chemicals of biological life, such as methane, according to a paper published in this week’s issue of the journal Nature.
How was This “Suitably Positioned” Planet Discovered?
An international team of 31 scientists found the planet after careful and repeated measurements of slight shifts in the color of the light coming from Proxima Centauri, which is a small, dim star in the Alpha Centauri system.
The shifts, which astronomers call “wobbles,” are caused by the gravitational tugging of a planet roughly 1.3 times the size of Earth on the parent star. Based on the timing of wobbles, scientists determined that the planet circles its host star in just 11 days, compared to Earth’s 365-day orbit around the sun.
That puts the planet far closer to its parent star than Earth orbits the sun. However, Proxima Centauri is so much smaller and dimmer than the sun that its planet’s orbit is suitably positioned for liquid water despite being just 4.4 million miles away.
What are the Chances Proxima B is Habitable?
Chances are good that it’s a viable, Earth-like planet today.Pedro Amado, Spanish Astronomer
But scientists are unsure if red dwarf stars like Proxima Centauri are good hosts for life. Planets orbiting close enough to keep water liquid would be blasted with 100 times more high-energy radiation than Earth receives from the sun, though what impact that would have on life is a matter of scientific debate.
Magnetic fields and an atmosphere offer a planet some protection. It is unknown if Proxima b has either. Before the discovery of Proxima b, the nearest Earth-like planet to the sun was circling a star known as Wolf 1061, located about 14 light-years away.
Proxima b may not be flying solo. However, more research is needed to determine if there are multiple planets circling Proxima Centauri.
$100 Million Project Deploying Thousands of Tiny Spacecrafts
The discovery announced on Wednesday is expected to bolster a $100 million project unveiled in April and backed by Russian billionaire Yuri Milner to develop a miniature laser-powered spacecraft that can make the trip to the Alpha Centauri system in about 20 years.
Worden, the executive director of Breakthrough Starshot, an initiative that aims to deploy thousands of tiny spacecraft to travel to our nearest neighboring star system and send back pictures said:
We hope to build a whole system that will send nanocraft to Proxima Centauri and Alpha Centauri within a generation.
(With inputs from Reuters and Nature journal.)
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