CASSINI, 1997 2017: REST IN SPACE
By the time you read this, NASA’S Cassini spacecraft will be but a memory – vaporized into nothingness 1.2 billion kilometres from home. But dry your tears: Scientists will be poring over its nearly 20-year life and 13-year sojourn around Saturn for years
WHY CASSINI MUST DIE: To protect the precious alien life that might lurk on Saturn’s moons — or could one day — Cassini is sacri icing itself for the sake of science. The plucky little probe found water on one of Saturn’s moons and organic soup on another. Left to sputter out on its own, it could crash into one of those worlds and pollute it with Earth germs, introducing the worst invasive species ever. So NASA decided it must let Cassini orbit closer and closer until it gets pulled into Saturn itself. Its last little bit of fuel will keep its antenna pointed at Earth for as long as possible as it transmits data on Saturn’s lowlying clouds. Then it will nosedive, lose contact with Earth, and burn up, becoming part of the gaseous planet it so dutifully studied for 13 years. 2016 Of the millions of dust grains Cassini samples around Saturn, it inds 36 that appear to be from worlds beyond our solar system.
Cassini ilms Saturn’s spinning polar hexagon: a six-sided jet stream churning at the planet’s north pole. As Saturn’s 30-year orbit around the sun progresses, the light changes and the vortex changes colour from blue to golden. 2006 Cassini sees the moon Titan’s hazy atmosphere of methane, the same hydrocarbon gas found in human farts. Titan has a methane cycle like Earth’s water cycle, with methane oceans, clouds and rain. 2005 The Huygens probe parachutes o Cassini onto Saturn’s moon Titan. It beep-boops around for just 90 minutes, snapping pictures of the hazy orange sky and pebbly landscape. 2006 2014 Water vapour and salt are seen spewing from geysers on the moon Encedalus, supplying raw material for one of the rings. Cassini later analyzes the moon’s ice grains and scientists conclude they came from a warm, salty, subsurface ocean of liquid water.
2004 2008 Cassini enters Saturn’s orbit. Its 12 instruments “sni ” the chemical composition of the atmosphere, measure magnetic ields and snap high-res photos. The results are so spectacular the mission is extended to 2017.
1998 99 Cassini swings around Venus twice, taking pictures and picking up speed due to the planet’s gravity.
1997 The Cassini spacecraft and its European hitchhiker, the Huygens probe, blast o from Cape Canaveral, Fla.