Venus Express (VEX) was the first Venus exploration mission of the European Space Agency (ESA). Launched in November 2005, it arrived at Venus in April 2006 and began continuously sending back science data from its polar orbit around Venus. Equipped with seven scientific instruments, the main objective of the mission was the long term observation of the Venusian atmosphere. The observation over such long periods of time had never been done in previous missions to Venus, and was key to a better understanding of the atmospheric dynamics. It was hoped that[needs update] such studies can contribute to an understanding of atmospheric dynamics in general, while also contributing to an understanding of climate change on Earth. ESA concluded the mission in December 2014.
With the GRAIL data, the astronomers were able to map the gravity field both in and around over 1,200 craters on the lunar far side. This region--the lunar highlands--is our Moon's most heavily cratered, and therefore oldest, terrain. Heavily cratered surfaces are older than smoother surfaces that are bereft of craters. This is because smooth surfaces indicate that more recent resurfacing has occurred, erasing the older scars of impact craters. Enshrouded in a dense golden hydrocarbon mist, Saturn's largest moon Titan is a mysterious mesmerizing world in its own right. For centuries, Titan's veiled, frigid surface was completely camouflaged by this hazy golden-orange cloud-cover that hid its icy surface from the prying eyes of curious observers on Earth. However, this misty moisty moon-world was finally forced to show its mysterious face, long-hidden behind its obscuring veil of fog, when the Cassini Spacecraft's Huygens Probe landed on its surface in 2004, sending revealing pictures back to astronomers on Earth. In September 2018, astronomers announced that new data obtained from Cassini show what appear to be gigantic, roaring dust storms, raging through the equatorial regions of Titan. The discovery, announced in the September 24, 2018 issue of the journal Nature Geoscience, makes this oddball moon-world the third known object in our Solar System--in addition to Earth and Mars--where ferocious dust storms have been observed. The observations are now shedding new light on the fascinating and dynamic environment of Titan, which is the second largest moon in our Solar System, after Ganymede of Jupiter. The team discovered that the Methone's density would be about 300 kilograms per cubic centimeter. That amounts to less than a third of the density of water, making Methone less dense than any other known moon or asteroid in our Solar System!