NASA has released a mosaic of images of Saturn’s moon Titan seen by the Cassini spacecraft before it was sent plunging to its death.
The images were taken on September 11, 2017, just four days before Cassini was purposefully destroyed in the atmosphere of Saturn. They show some of the lakes and seas near Titan’s north pole – with Titan being the only world other than Earth known to have bodies of liquid on its surface.
Cassini took the images from a distance of about 140,000 kilometers (87,000 miles) from Titan, as it made its way towards the atmosphere of Saturn. This was a few months after it had done its last close flyby of Titan.
In the image we can see Kraken Mare, which is the largest body of liquid on the surface of Titan at 400,000 square kilometers (150,000 square miles). Of course on Titan these aren’t bodies of water, but rather liquid hydrocarbons, with similar ingredients to those found in jet fuel.
Elsewhere we can also see Ligeia Mare, which at 126,000 square kilometers (49,000 square miles) is the second largest body of liquid on Titan. It’s thought its liquid may be connected in some way to Kraken Mare.
We can also see clouds in the image, something that’s super exciting to scientists. They have been difficult to spot on the moon before, but they are fascinating to study as they tell us more about Titan’s weather. Cassini had seen clouds before at the south pole, but scientists had predicted they would have appeared earlier in the north as it turned from spring to summer.
“[A]tmospheric models predicted summer clouds over the northern latitudes several years ago,” Dr Elizabeth Turtle from the Cassini Imaging Science Subsystem (ISS) said in a statement.
“So, the fact that they still hadn't appeared before the end of the mission is telling us something interesting about Titan's methane cycle and weather."
With Cassini now gone, a lot of questions about Titan remain unanswered, and will remain so for the foreseeable future. For example, we aren’t exactly sure how these lakes formed. And there’s so much more we want to learn about its climate.
Titan can seem strangely Earth-like at times, with rain, clouds, a methane cycle similar to our water cycle, and more. Sadly we won’t get any new views of it until another spacecraft visits the system. But Cassini did a wonderful job of telling us more about it.
"Titan is a fascinating place that really teases us with some of its mysteries," Dr Turtle added in the statement.