SPACE scientists at Aberystwyth University are following the progress of the Cassini spacecraft as it nears the end of its 20-year mission to Saturn.

Prof Manuel Grande is co-investigator on three scientific instruments on board the craft which is due to plunge into the Saturn atmosphere today.

Launched from Cape Canaveral in October 1987, Cassini and the European Space Agency probe Huygens took seven years to reach the ringed planet.

Huygens landed successfully on one of Saturn’s moons, Titan in 2005.

Named after the Italian-French astronomer Giovanni Domenico Cassini, who discovered Saturn’s rings, one of the Cassini space probe’s objectives was to determine the three-dimensional structure and dynamic behaviour of the rings.

In April this year, Cassini embarked on a final programme of 22 orbits of Saturn, each taking about six and half days to complete.

Travelling at between 75,000 and 78,000 miles per hour, the probe has been flying through a hitherto unexplored region of the Saturnian system in an attempts to solve the mysteries of the mass of Saturn’s rings and determine the length of Saturn’s day.

Prof Grande, head of solar systems physics at Aberystwyth University, has been involved with the Cassini mission from an early stage.

He contributed to building Cassini’s Plasma Spectrometer, known as CAPS, and its Cosmic Dust Analyser - CDA.

Prof Grande said: “The data gathered during the Cassini mission has changed our understanding of the universe.

“Another important instrument on the lander has been the camera on the Huygens probe as it descended towards the surface and complemented with the radar on the Cassini orbiter.

“That has given us a picture of the surface of Titan, which has been very surprising.

“It turns out that Titan has got big lakes, sand dunes and rivers which from space look pretty much like rivers on earth.

“It’s also got seasons. In many ways it’s the place in the solar system that if you just look at it, looks most like the earth.

“The difference is that it is much much colder, and the liquid is liquid methane similar to that in camping gas cylinders, and the rocks are ice.

“That is completely surprising because before we went to Titan, we had never seen under the atmosphere.

“So it tells us there is great argument for going to new places, and when we do, we find out new and unexpected things.”