[ Music ]
Titan is a moon of Saturn.
It’s the second largest moon in the Solar System and it is about two times larger
than Earth’s Moon and actually bigger than the planet Mercury.
Titan is also interesting – it’s the only moon in our Solar System with an atmosphere.
It’s surrounded by sort of an envelope of gaseous nitrogen
just like our own Earth is.
Titan was first discovered by telescope observations back in the mid-1600's.
The first spacecraft observations were made of Titan during flybys through
the outer Solar System – that was in the late seventies and in the eighties.
But we really were able to explore Titan in-depth with the Cassini-Huygens mission.
The Huygens probe was dropped into the atmosphere of Titan,
and it made measurements of chemistry, and it took images as it fell to the surface,
and that was back in 2005.
And since then, the Cassini Orbiter made over a hundred close flybys of Titan.
Cassini in its design with the different instruments – we purposely were picking
instruments that could go into longer wavelengths into the infrared
so we could really understand the moon.
We were able to basically peel back the layers of Titan
to really see what was below, and it was remarkable – very Earthlike.
The landscape is similar to Earth’s in many, many ways, but with a little bit of a twist.
So on Titan, you can find dunes, you find lakes, there are river channels,
the atmosphere is very dense and you can get clouds and smog and you even get rain.
We saw winds, we saw seasons, and one really important thing we saw was liquids
pooling in the polar regions on the surface – a lot of it.
But because Titan is so cold, those features are all made of very exotic materials
compared to what we would find on Earth.
So the lakes and the rain are made of liquid methane, the crust that forms
the surface of Titan is actually water ice, but it’s so cold that it's as hard as rock,
and in the atmosphere we get this organic chemistry that forms large
organic molecules and particulates – they fall down to the surface
and then behave like dust or like sand does.
So it makes us want to go back to really understand the complex,
organic environment of that surface and what it means
for either past life or maybe future life.
[ Music ]