• After spending nearly two decades in space, NASA’s Cassini – an unmanned spacecraft sent to study Saturn – is ready for its final mission. On Tuesday, April 4, NASA will hold a press conference to unveil the beginning of Cassini’s last mission segment, called the Grand Finale. Here’s the lowdown:

When was Cassini launched?

• Cassini was launched on October 15, 1997. After taking on a voyage passing through the flybys of Earth, Venus and Jupited, Cassini began orbiting Saturn since June 2004, studying the planet, its rings and its moons.

What does this final mission entail?

• A final close flyby of Saturn’s moon Titan on April 22 will reshape the Cassini spacecraft’s orbit so that it begins its final series of 22 weekly dives through the unexplored gap between the planet and its rings. The first of these dives is planned for April 26. Following these closer-than-ever encounters with the giant planet, Cassini will make a mission-ending plunge into Saturn’s upper atmosphere on September 15.
• To put it in simpler terms, Cassini will explore areas of Saturn that have been untouched up until this point. It will get the closest look ever at Saturn’s outer rings.

What has Cassini revealed so far?

• Cassini’s most detailed look came after landing on Titan, Saturn’s largest moon, from where it beamed pictures back to earth. It was revealed later that Titan was an earth-like world with rain, rivers, lakes and seas.
• Cassini discovered previously unknown moons in orbit within the planet’s rings. These include Methone, Pallene, Polydeuces, Daphnis, Anthe and Aegaeon.
• One of its most important discovery was Enceladus – a frozen moon that shoots out icy jets as it gets warped by Saturn’s gravity.
• The spacecraft made a series of discoveries relating to Saturn’s rings. Vertical structures in the ring were imaged for the first time.

Source: The Hindu