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As Voyager 2 closed in on Enceladus from 440,000 to 268,000 kilometres it took a series of pictures in which the perspective shifts from the anti-Saturn to the trailing hemisphere and north migrates from the upper right to the right, with the north pole on the terminator.

As Voyager 2 closed in on Enceladus from 240,000 to 108,000 kilometres it took a series of pictures in which the perspective shifts from the trailing to the Saturn-facing hemisphere and north migrates from the right to lower right, with the north pole on the terminator in Samarkand Sulcus.

As it closed between 1.5 million and 800,000 kilometres. Voyager 2 took a series of three images of Tethys showing the vast crater xsi

Odysseus whose central peak lies at 130 degrees west. Later, with the crater now beyond the terminator, it recorded the shifting S-

perspective from the anti-Saturn hemisphere at 680,000 kilometres, around the trailing hemisphere onto the Saturn-facing hemisphere 2 at 282,000 kilometres. In each case North is towards the top. The later sequence revealed the global extent of Ithaca Chasma. The prominent crater Penelope on the trailing hemisphere is the strange albedo feature seen by Voyager 1. ยก3

the vast crater, suggested that they were opened by the shock of that impact. Tethys has a bright, heavily cratered terrain and a less intensely cratered, somewhat darker, plain which could be the result of geological activity. Unfortunately, some 30,000 kilometres short of the 120,000-kilometre point of closest approach - at which time the best terminator view would have been afforded - the imaging sequence was preempted by the fault in the scan platform, and the best view was found to be that from 600,000 kilometres.

The scan platform was coaxed back to life on 27 August. However, the departure trajectory was at a fairly steep angle to the system's equatorial plane, so once it was through the ring plane it rapidly left the moons behind. Only distant Phoebe, whose orbit is more or less in the plane of the ecliptic, was favourably presented, and as the 2.2-million-kilometre fly-by on 4 September would not require the scan platform to slew in its high rate this unusual object was investigated. It was found to be more or less spherical and about 220 kilometres in diameter, with a very dark cratered surface showing a few relatively bright patches. Although at that time no main belt asteroids had been inspected by spacecraft to provide a basis for comparison, it seemed likely from spectroscopic considerations that it is similar to the reddish asteroids whose spectra suggest that they are 'primitive' objects made of condensates left over from the solar nebula - either that or a giant cometary nucleus - and hence that it was indeed captured by Saturn.

Three views of Phoebe taken by Voyager 2 on 4 September 1981 as it flew past at a range of 2.2 million kilometres. It is spheroidal and about 220 kilometres in diameter. At 6 per cent, its albedo is darker than the icy moons orbiting closer in. The 'bright' patches may be the sites of impacts. Because it is in an elliptical 550-day retrograde orbit, its rotation has not been captured; the imagery indicated that its period is 9 to 10 hours.

Three views of Phoebe taken by Voyager 2 on 4 September 1981 as it flew past at a range of 2.2 million kilometres. It is spheroidal and about 220 kilometres in diameter. At 6 per cent, its albedo is darker than the icy moons orbiting closer in. The 'bright' patches may be the sites of impacts. Because it is in an elliptical 550-day retrograde orbit, its rotation has not been captured; the imagery indicated that its period is 9 to 10 hours.

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