The US-led Cassini probe to Saturn will destroy itself in the coming hours.

The $4bn (£3bn) mission is ending 13 years of discoveries at the ringed planet by ditching itself in the atmosphere.

With an expected entry speed of 120,000km/h (76,000mph), the spacecraft will rapidly be torn to pieces.

Scientists, however, hope to gain new information on the chemical composition of Saturn's gases just before Cassini loses radio contact with Earth.

That is likely to occur just after 04:55 local time here at mission control - the Nasa Jet Propulsion Laboratory (JPL) in Pasadena, California (11:55 GMT; 12:55BST).

Image copyrightNASA/JPL-CALTECH/SSI/JASON MAJOR

It will be a bittersweet moment for the hundreds of mission researchers who have come from all over the world to be in the Los Angeles County town for the occasion.

Former US space agency chief scientist Ellen Stofan is part of the probe's radar instrument group.

"We've done amazing science; it's an amazing team. And I think we can celebrate that we've really eked every little bit of science that we could out of the Cassini spacecraft. But then it's what's next?

"We want to go back to Titan, we want to go back to Enceladus; there's so much we don't know about the interior of Saturn, so people have talked about Saturn probe missions. There's a lot more to be done," she told the BBC.

Cassini: A mission of 'astonishing discovery'

Image copyrightNASA/JPL-CALTECH/SSI

• Meet the people who made Cassini happen
• In Pictures: Cassini probe's greatest shots
• What were the mission's biggest findings?

Cassini has revolutionised our understanding of the sixth planet from the Sun.

It has watched monster storms encircle the globe, and witnessed the delicate interplay of ice particles move through its complex ring system.

And then there are those remarkable moons Titan and Enceladus, which host vast bodies of liquid water beneath their icy shells and where scientists say conditions may be favourable for simple life to exist.

But after taking hundreds of thousands of pictures