The first close-up images of Saturn's moon Tethys have been sent to Earth from the Cassini spacecraft, which flew past the moon on Saturday. As well as the expected craters and chasms, one image reveals a peculiar, spear-shaped feature.
Tethys is one of Saturn's inner moons, orbiting about 300,000 kilometres from the planet - closer than our Moon is to Earth. Scientists already knew that the 500-kilometre moon bears one huge crater, Odysseus, and a unique giant canyon system called Ithaca Chasma.
They are now hoping to find out how Ithaca Chasma formed - whether, perhaps, it is related to the impact that created Odysseus. They also hope to discover what processes have resurfaced some areas of Tethys, smoothing out the old, heavily cratered terrain.
Cassini's highly detailed pictures should help. Although the spacecraft was not originally supposed to come closer than 30,000 kilometres, the navigation team worked out a way to skim within 1500 kilometres of Tethys without upsetting the rest of Cassini's complex schedule. From this close, some of the images reveal details smaller than 20 metres across.
Mission scientists have only just begun looking at the new data, but they should release their initial conclusions in the coming days. They will want to get as much as possible out of this visit, because Cassini may never return to Tethys.
, it looks just like a rock with a tail behind it, maybe a very small meteorite that came in at a very slow speed and glided rather than crashed?
Your head is humming and it won't go, in case you don't know, the piper's calling you to join him
