It’s business as usual for the Cassini spacecraft until it’s time to say goodbye in September 2017, and some of the latest images it captured tell us more about Saturn’s moons. The spacecraft’s cameras, for one, produced two very different views of Titan’s high northern latitudes. As you can see in the image after the break, one (the black-and-white photo) clearly shows the surface features of Saturn’s largest moon. The other shows a moon whose surface is obscured by bright clouds. These were taken within the same period during the spacecraft’s Titan flybys on June 7th and July 25th.
[Image credit: NASA/JPL-Caltech/SSI/Univ. Arizona/Univ. Idaho]
So if the images were taken within the same period, how come one has clouds while the other has none? According to the Cassini team, the answer lies with Titan’s hazy atmosphere and the spacecraft’s two different cameras: the Imaging Science Subsystem (ISS) and the Visual and Infrared Mapping Spectrometer (VIMS). The clouds are supposed to be there, because computer models show they should be present when the northern summer approaches. However, they’re not visible in the black-and-white image captured by ISS, because they appear thinner than the haze at the shorter, near-infrared wavelength the instrument uses. On the other hand, they look thicker at the longer infrared wavelengths used by VIMS, which took the other photo.
In addition to confirming that clouds hover over the northern part of Titan when summer approaches, Cassini also recently took one of the highest-resolution images of another Saturn moon called Pandora. The spacecraft snapped the photo during its closest ever Pandora flyby on December 18th, 2016.
from Engadget http://ift.tt/2imW6yK