Nasa are set to reveal an "amazing" discovery on Thursday, according to one of the space agency's senior scientists.

Dr Alan Stern, a planetary scientist and Principal Investigator on Nasa's New Horizons Pluto mission, made the exciting announcement whilst speaking at the University of Alberta in Canada.

Whilst speaking about the latest images of Pluto captured by the New Horizons probe, Stern said: "Nasa won't let me tell you what we're going to tell you on Thursday. It's amazing."

Last week, Nasa unveiled new images of the surfce of Pluto, which show a landscape of mountains, craters and gorges.

New images of Pluto's surface

As reported by The Guardian, Stern said: "This world is alive."

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

There is no word yet on what the announcement could be, with Nasa taking the same line of secrecy as they did at their last big event - the announcement of the discovery of water on Mars.

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

However, a number of unknowns remain. Pluto has vast mountainous dune fields, a multicoloured surface, and a number of other mysterious features that have not been explained by science.

Thursday's announcement could relate to any one of these.

Nasa has had a year of big discoveries. From the discovery of flowing water on Mars, to the identification of 'Earth 2.0' - Kepler 452b, the most Earth-like planet every discovered - the leading space agency has been holding momentous announcements fairly regularly over the last few months.