Ammon News - It's one of the biggest unanswered questions in science: are there aliens out there, and if so, where are they hiding?

Now, a discovery by NASA has raised the tantalising possibility that we're not alone after all.

The US space agency has discovered an exoplanet 146 light-years away that is 'remarkably similar to Earth'.

Dubbed HD 137010 b, the planet might fall just within the outer edges of its star's 'habitable zone', meaning there could be liquid water on its surface and a suitable atmosphere for life.

However, any potential aliens living on this planet would need to be well adapted for cold weather.

'Although of a stellar type similar to our Sun, the star, HD 137010, is cooler and dimmer,' NASA explained.

'That could mean a planetary surface temperature no higher than -90°F (-68°C).

'By comparison, the average surface temperature on Mars runs about -85°F (-65°C).'

NASA's scientists discovered the rocky exoplanet using data gathered by the Kepler Space Telescope.

This discovery comes from a single 'transit' – the planet crossing its star's face – which was detected during Kepler's second mission, K2.

While one transit doesn't sound like much, this was enough for the scientists to estimate the exoplanet's orbital period.

By tracking the time it took for the planet's shadow to move across its sun's face, the team estimated that the planet has an orbital period of 10 hours, compared to Earth's 13 hours.

Their calculations also suggest it's probably freezing, although there is a chance HD 137010 b could turn out to be a temperate or even a watery world, according to NASA.

'It would just need an atmosphere richer in carbon dioxide than our own,' the team explained.

Based on modelling of the planet's possible atmospheres, NASA says there is a 40 per cent chance that the planet falls within the 'conservative' habitable zone around the star, and a 51 per cent chance that it falls within the broader 'optimistic' habitable zone.

'The planet has about a 50–50 chance of falling beyond the habitable zone entirely,' the experts cautioned.

Daily Mail