With thousands of images taken by various probes sent to Mars, it would seem inevitable that unusual or puzzling objects might be seen in some of them. And of course, there have been, most notably the famous “Face on Mars” first seen in low-resolution Viking orbiter images in the 1970s. Higher-resolution images taken later by other orbiters with better cameras showed it, and nearby interesting formations, to be just natural hills and mesas. Despite that, other curious things are seen in both orbital and ground images from time to time, although they almost always have a simple prosaic explanation. Another such oddity was just recently seen in an image taken by the Mars Reconnaissance Orbiter (MRO), which has attracted some attention. Most likely it is a natural rock formation, but it’s also not, as described by the tabloid Daily Mail, a “spherule” either.
Saturn’s moon Titan is the only other body in the Solar System besides Earth known to have liquids on its surface. In Titan’s case, they are rivers, lakes and seas of liquid hydrocarbons (methane/ethane) instead of water. There is even methane/ethane rain, which further mimics Earth’s hydrological cycle. For the most part, the lakes and seas are fairly smooth, with only small amounts of wave activity. But now, new research suggests that those lakes and seas might be quite fizzy at times – with periodic bursts of nitrogen bubbles.
It’s been a long time coming, but NASA’s new mission to Jupiter’s moon Europa now has a formal name: Europa Clipper. The spacecraft, to be launched in the early 2020s, will conduct multiple close flybys of the moon, with the goal of determining just how habitable it actually is. With a global salty ocean just beneath its icy crust, Europa is thought to be one of the best places in the Solar System to search for possible alien life.
When it comes to places in the Solar System to search for possible alien life, Saturn’s moon Enceladus is now right near the top of the list. Like Jupiter’s moon Europa, it has a subsurface ocean of water, and even plumes/geysers of water vapour which erupt from fissures in the icy surface near the south pole. Those plumes contain organics as discovered by the Cassini probe and there is evidence for hydrothermal activity on the ocean floor, just like on Earth. The fissures are warmed by heat from below, and now there is evidence that some of them are even warmer than expected, meaning that water could be closer to the surface than previously thought.
The seven Earth-sized exoplanets orbiting the star TRAPPIST-1 generated a lot of excitement when their discovery was announced last month. This is the largest collection of Earth-sized worlds in one planetary system found so far, and some of them are well within the star’s “habitable zone” where temperatures could allow liquid water to exist on their surfaces. Little else is known about the actual conditions on these planets so far, but NASA’s Kepler Space Telescope has also been observing TRAPPIST-1 in recent weeks.
Mars is a busy place these days, with multiple rovers and orbiters exploring the planet. Out of the several spacecraft currently in orbit, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) is a fairly recent addition, having been at Mars for just over two years now. Usually, things are pretty routine, but this week the spacecraft had to make an unplanned evasive maneuver – to avoid a collision with one of Mars’ two small moons, Phobos!