Goldilocks planet

A team of astronomers from Germany and Britain have discovered a new planet, which has the potential to be habitable.

The planet dubbed "HD 40307 g" is located about 44 light years away in the Goldilocks Zone of a sun - an area around a sun or star, where water can exist without evaporating due to heat, according to University of Göttingen astrophysics researcher Guillem Anglada-Escudé.

Scientists call the Goldilocks Zone the liquid water habitable zone. It is neither too hot nor cold, just like the porridge in "Goldilocks and the three bears."

"What we know is that the temperature on the surface would be like the temperature we have on Earth because it's the right distance from the star," says Anglada-Escudé.

More research to come

From Earth, the researchers were able to determine the possible temperature of the planet based on the brightness of the sun it orbits.

"The estimated mean temperature of HD 40307 g is around nine degrees (Celsius), which means that you can have up to 30 or down to -10 degrees, as on Earth," Anglada-Escudé says.

The recently discovered HD 40307 g is now ranked fourth in a list of potentially habitable planets by the Planetary Habitability Laboratory at the University of Puerto Rico.

But its ranking could change depending on further data that Anglada-Escudé and his fellow researchers collect.

At this time, more research needs to be done on the planet's atmosphere to see whether it contains biomarkers - gases like oxygen, carbon dioxide and methane, which would prove there is life on the planet.

Light years away

Planet HD 40307 g is 42.36 light years away from Earth - it would take an object traveling at the speed of light 42.36 years to reach the planet.

Currently, we can break the sound barrier, but even super sonic speed doesn't cut it. It's impossible for us to gather any conclusive data on the ground.

"This discovery is useful," says Ulrich Köhler at Germany's Institute of Planetary Research (DLR). "But it's too soon to talk about a second Earth. The planet is in a habitable zone, but based on the data we have now, talking about life there is speculation."

The search for exoplanets (planets outside our solar system) became more significant in the late 90s - the first exoplanet was discovered in 1996.

Since then, around 800 exoplanets have been discovered.

And most of them are similar to gas planets like Jupiter, making them inhabitable.

The Planetary Habitability Laboratory lists up to 27 potentially habitable planets on which life remains unconfirmed.

The question is whether such knowledge is of any benefit to us down on Earth.

"The issue is very touchy because you can awaken expectations in the public," says Köhler, suggesting such expectations are unrealistic.

But the University of Göttingen's Anglada-Escudé is more optimistic.

"Who knows what technology will give us by the end of the century?" he asks.

So, we may well be able to travel to HD 40307 g in about a hundred years.