Astronomers discovered evidence that there is a third planet near the nearest star to the sun. This confirms the belief that planets exist around all stars in the galaxy.

Although the planet discovered is smaller than Earth, and likely too hot for human habitation, it still has the potential to support life on Proxima Centauri. This galactic neighbor, Earth, could also be found.

“The planet is not within the star’s habitable zone — it’s orbiting too close,” said astronomer João Faria, the lead author of a study published this month in the journal Astronomy & Astrophysics that details the discovery. It is unlikely water could be liquid, and the conditions for life are not right.

In fact, the new planet is so close — about a tenth of the distance between the sun and Mercury — that it takes just five days to complete an orbit around its star.

Also, it’s likely to be “tidallylocked”, as the moon to Earth is. One face points towards Proxima Centauri. Faria stated that this could lead to extreme temperatures and limit the possibility of the planet having a stable atmosphere.

Astronomers, however, are thrilled by this discovery, regardless of the possible hostile environment on the planet.

Faria is a researcher from the Institute of Astrophysics and Space Sciences of the University of Porto, Portugal. He said that it suggested the Proxima System could contain “packed full of planets”.

In an email, he stated that the breakthrough also affects the way astronomers seek out planets near distant stars. He said this could be a step forward in the search, and it may lead to more discovery.

Faria and co-authors will need to confirm the discovery of this new planet with other observations. However, Faria says they saw tiny variations in Proxima starlight. — “wobbles” caused by the planet’s gravity.

Similar methods were employed to find the second and third planets around Proxima, in 2016 as well as the first one in 2019.

The latest search however used light collected by a new spectrograph at the Very Large Telescope on a mountaintop in the Atacama Desert of northern Chile — a more sensitive instrument than used before.

Faria explained that Faria is now able to use instrumental precision to pick up such subtle signals. This opens up the possibility for finding Earth-like planets around stars like the sun, not so distant in the future.

Proxima Centauri (the third star of Alpha Centauri’s system) looks just like one bright star from Earth.

It’s just over four light-years away, or about 25 trillion miles — but despite that vast distance, it’s the closest star system.

The naked eye can only see the light coming from Alpha Centauri A or Alpha Centauri B.

Although they orbit one another, their distances are sufficient to ensure that they don’t interfere with the other’s solar systems.

And because Alpha Centauri A and B are both remarkably like the sun, it’s possible life could have evolved on their planets or moons — so scientists plan to look for them with a dedicated space telescope.

Proxima Centauri on the other side is a very small, dim, red dwarf star found by telescopes in 1915 far from the two main stars of the system.

Technically, Proxima is the closest star to the sun — about a trillion miles closer than the others — until its orbit takes it further away in about 25,000 years (its name comes from the Latin word for “nearest”).

Contrary to Alpha Centauri A & B, which had no confirmed planets, there are now three discovered planets around Proxima.

They are not thought to have any similarities to Earth. However, Proxima, an active “flarestar”, regularly gives its planets intense radiation bursts.

But it’s still possible that life could have evolved on at least one of its planets, said Guillem Anglada-Escudé, an astronomer at the Institute of Space Sciences in Barcelona, Spain.

The team which announced was led by him. Proxima’s first planet in 2016. That planet was found to be about the size of Earth and within Proxima’s narrow habitable or “Goldilocks” zone, where it’s neither too hot nor too cold — “just right” — for oceans of water on its surface.

There may be oceans in the area, according to observations. They could also replenish atmospheric gas that has been effected by Proxima’s flares. The oceans may also serve as barriers to flares and it is possible that marine life has evolved.

Anglada-Escudé expects more planets will be found around Proxima Centauri and other stars as astronomical instruments and techniques improve.

He said, “Within a decade we should be in a position to detect these worlds directly.” The idea is to find life and to determine if chemicals are present on a planet’s spectrum.