Nasa is about to make an “amazing” announcement about Pluto, according to a senior scientist, who described the planet as “alive”.

Dr Alan Stern, who leads the New Horizons mission to Pluto, said during a university speech that the agency was about to reveal new information today.

"Nasa won't let me tell you what we're going to tell you on Thursday,” he said during the speech. “It's amazing."

That was the only thing that Stern said, and the agency has otherwise remained tight-lipped about its announcement. Usually, Nasa trails its big announcements and hosts them live on its Nasa TV channel.

But Stern said that “the world is alive”, leading many to hope that the discovery will be aliens. But it almost certainly won't be.

“It has weather, it has hazes in the atmosphere, active geology... Every week I am floored."

It’s unlikely that the craft will be able to reveal life on the dwarf planet — as with Mars, any life there is almost certainly microbial, and so would need something to actually be on the planet to be sure.

But it may still be a huge announcement about the nature of the planet and perhaps how well it would support life: Nasa has already said that discoveries from the New Horizons mission have completely changed its understanding of the dwarf planet, and it’s only got a tiny amount of the information back.

And some scientists have suggested that Pluto could support alien life.

In pictures: Nasa mission to Pluto Show all 5 1 /5 In pictures: Nasa mission to Pluto In pictures: Nasa mission to Pluto Mission to Pluto The 3 billion miles journey to Pluto began nine and a half years ago NASA In pictures: Nasa mission to Pluto Mission to Pluto A close-up image of a region near Pluto's equator reveals a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body NASA In pictures: Nasa mission to Pluto Mission to Pluto Hydra, one of Pluto's moons, in an image obtained by the New Horizons spacecraft In pictures: Nasa mission to Pluto Mission to Pluto Charon, Pluto's largest moon, in a image taken from a distance of 289,000 miles (466,000 kilometers) NASA In pictures: Nasa mission to Pluto Mission to Pluto A NASA graphic of a spectra obtained by the Ralph instrument on the New Horizons spacecraft revealing methane ice on the frozen surface of Pluto NASA

Soon after New Horizons made its flypast, Brian Cox said that the probe “showed you that there may well be a subsurface ocean on Pluto, which means — if our understanding of life on Earth is even slightly correct — that you could have living things there".

There are a range of new findings that could increase the likelihood of Pluto being able to support life, even if they don't show that there is life already there. The discovery of water, for instance, would hugely increase the chance of alien life as it has on Mars — especially if it is warm.

Explainer: Water on Mars

Only 10 per cent of the data from the New Horizons spacecraft has been downloaded so far, Dr Stern said. That means that much more is likely to be revealed as more images are sent back.