Epress.am News from Armenia
NASA’s Cassini spacecraft successfully completed its second-closest encounter with Saturn’s icy moon Helene on Jun. 18, 2011, beaming down raw images of the small moon. At its closest point, Cassini flew within 4,330 miles (6,968 kms) of Helene’s surface.
It was the second closest approach to Helene during its entire mission. In Mar. 2010, the spacecraft came much closer, at a distance of 1,800 kms; however, the images were not as clear.
According to scientists, the new series of photographs will create a map of the surface of Saturn’s moon. This will allow scientists to better understand the structure and evolution of the 30-km across floating iceberg, as well as, perhaps, clarify the origin of the unusually smooth and streaked terrain that appear along with the craters and hills in the photographs.
Helene, discovered on Mar. 1, 1980, by J. Lecacheux and others, is referred to as a Trojan satellite because it orbits Saturn in the Lagrange point of the larger moon Dione. According to NASA, Helene is unusual because it circles Saturn just ahead of the large moon Dione, making it one of only four known Saturnian moons to occupy a gravitational well known as a stable Lagrange point.
Photo: NASA/JPL-Caltech/Space Science Institute