AstroTalk Episode April 13, 2017

Enceladus and Images of Mars from MRO and HIRISE and MAVEN

3:05pm - 3:29pm

Cassini is showing off: well, just a little. NASA is revealing details of information gleamed from a Cassini dive through plumes of vapor as it flies through Enceladus' atmosphere. Enceladus is the icy moon of Saturn. A sub-surface ocean is thought to exist on Enceladus, hightening the possibility that life could exist on the moon. For life to exist (as we know it) 3 ingredients are necessary: liquid water, the right chemical ingredients, and a source of energy for metabloism. Enceladus is thought to have all of these. The article describing this research can be found on, in "NASA Missions Provide New Insights into 'Ocean Worlds' in Our Solar System", dated April 13, 2017.
Also, in another region of our Solar System, the Mars Reconnaissance Orbiter (MRO) is exploring a region called, "Noctis Labyrinthus". MRO has captured a striking image of a mesa, just one of several in the region known as Valles Marineris. The mesa is ~ 0.4 km wide, probably composed of sedimentary deposits that are also eroding. The image is magnificent, and can be found on Another image from MRO shows a hill on Mars, on the South Pole layered deposits. The hill protects the icy layers from erosion, so the image shows the hill with beautiful spiral patterns. In another finding from MRO, over 500 new impact events have been exposed from before and after images of the Southern Middle Latitudes. The new images show shallow sheets of ice that have interested scientists, because ice has not been previously detected on Mars at these latitudes. The scientists hope to better map the ice distribution on Mars, with help from this new data. Staying with Mars, NASA is using the MAVEN spacecraft (Mars Atmosphere and Volatile Evolution) to examine the charged metal atoms that exist high in Mars' whismy upper atmosphere, or ionosphere. This is the first direct detection of atoms like these in a planet other than Earth. Metallic ions have long lifetimes, so studying these ions can help scientists infer the motion of Mars' ionosphere. With this information, it is hoped scientists can better understand how Mars lost most of its atmosphere, making it the dry, dusty world it is today. Scientists believe that ions exist in the atmospheres of other planets in our Solar System. When other spacecraft have tried to send signals to Earth from locations on other planets, such as Jupiter or Saturn, parts of these signals have sometimes been blocked. Scientists have inferred that the presence of metal ions in the ionospheres of these other planets have been responsible for the signal blockage, but no direct proof of this has been offered. Another curious find on Mars was that the metal ions in Mars' ionosphere behave differently than the ions in Earth's ionoshpere. This could be due to the presence of a magnetosphere on Earth, and a lack of one on Mars. Scientists with MAVEN are also trying to learn about the formation of high altitude clouds on Earth and Mars, and what role the ions in the ionospheres have on this phenomenon.