A University of Auckland cosmologist says we may have just discovered the first planet we'll travel to.

The European Southern Observatory discovered the potentially earth-like planet which for now, is named Proxima b.

It sits within the Goldilocks temperature zone, meaning liquid water, and life, could exist on its surface.

Professor Richard Easther said the planet is orbiting a star, and it's the closest to Earth making it the most viable possibility.

"Whereas other planets we've found, either they're very very close to the sun, they're like being inside a furnace or they're very very far from the sun in which case everything would be frozen solid so finding a medium size planet that's not too cold or not too hot that's exactly the bowl of porridge that we were looking for."

Professor Easther said Proxima b's proximity to Earth also makes it a unique target for space travel.

He said if we were going to get to any 'goldilocks' planets we're not going to find one closer, and scientists have played with the idea of spacecrafts capable of taking generations of people the distance needed.

But the idea still remains in the realms of dreams at the moment - he said that kind of travel would be reserved for a society that was much wealthier than any on Earth today.

But until scientists know its composition, they won't know if it has water and is worth travelling to in the first place.

If Proxima b's composition is similar to Earth's it would be around 30 percent larger than Earth, and have a slightly stronger gravitational pull.