NASAâs Cassini spacecraft met a fiery end in the atmosphere over Saturn Friday. York University astronomy professor Paul Delaney and former Canadian astronaut Chris Hadfield highlighted the probe's five greatest discoveries from its 13 years orbiting the planet.
âIt started to tantalizingly teach us about the universe itself,â Hadfield told ŰÎŰ´ŤĂ˝ Channel Friday.
Here are Delaneyâs and Hadfieldâs top picks from what we learned about Earthâs distant solar neighbour.
1. Geysers on Enceladus
Delaney hailed the probe for revealing the true nature of Saturnâs tiny moon, Enceladus. Little was known about Enceladus until Cassini revealed a global ocean of liquid salt water under its crust, as well as chemical-spewing geysers that hint at the possibility Enceladus might be capable of supporting life.
âWe know thereâs a place, even way out there in the solar system, that has liquid water and a hot central core, [which are] the kind of conditions that life developed on Earth 4 billion years ago,â said Hadfield.
2. Titan
Delaney told ŰÎŰ´ŤĂ˝ Channel Thursday Cassini has helped fill in a lot of the gaps in what scientists know about Titan, Saturnâs largest moon. He said the probe essentially defined Titan as a âreal body in the solar system,â and revealed a vast amount of information about its atmosphere. Among those discoveries was the fact that the atmosphere is over 95 per cent nitrogen, making it very similar to Earthâs atmosphere â although still lacking in oxygen.
3. Lakes of methane
Delaney said one of the biggest surprises of the trip was that the lakes dotting Titanâs surface appear to be rich in methane. The discovery showed that rain falls on Titan, and provided evidence of an underground ocean that might hold water and ammonia.
âIf you glance at it, it could be somewhere on Earth,â said Hadfield. âTo think that that exists out there just opens our minds to the possibilities of environments around the solar system and the universe.â
4. Saturnâs polar hexagon
Cassini offered astronomers their closest look yet at a bizarre hexagonal shape at one of Saturnâs poles, which many are still trying to explain.
5. Saturnâs rings
Delaney and Hadfield both said the single greatest discovery of the mission has been new insights into the intricate nature of Saturnâs rings.
âIts ring structure is far more complex than we had anticipated,â Delaney said. âItâs just a wonderful choreography of interactions for all of the Saturnian system components.â
âNow we understand [the rings] are primarily ice, and water ice, and itâs a temporary thing,â added Hadfield.
To truly reveal the wonders of Saturn, we had to go there. Look back at 's 13 amazing years exploring the planet
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