The continued exploration of the planets and moons in our Solar System have revealed many strange things, including that Earth is not the only place with oceans and seas. Mars once had lakes and possibly oceans in the distant past, some of the icy moons in the outer Solar System such as Europa and Enceladus currently have subsurface oceans and seas, and Titan has seas and lakes of liquid methane/ethane on its surface. That’s weird enough, but now there’s a new twist: Venus may have had oceans of liquid carbon dioxide (CO2) in the past.
This is a great image to start 2015 with: a new panoramic view of a small but very rocky hill in the Pahrump Hills area on Mars, taken by the Curiosity rover. You can see the larger versions here on Flickr. When you zoom in, you can see a lot of small lighter-coloured patches on rocks in the right side of the panorama and even a small “cave” with a flow of sand coming out of it. There’s a lot of geology and history here; as we’ve seen before, the scenery is very reminiscent of the American southwest. Thanks to Hortonheardawho from the Mars Forum for his excellent panorama stitched together from individual Curiosity images.
With so many exoplanets now being discovered on a regular basis by astronomers, the focus has turned to what number of them might be habitable for some kind of life. For life as we know it at least, that depends on a number of factors, including being in the “habitable zone” of stars, where liquid water could exist on the surfaces of smaller, rocky planets like Earth. It has been thought that planets with extreme axial tilts, even horizontal to the plane of their orbits, would be less likely to host life. But now a new study suggests that they could still be quite habitable, if they are covered by oceans.
A beautiful new photo from Cassini showing Saturn’s largest moon Titan below the plane of the giant planet’s rings. What a view!
There is a report which has been getting a lot of attention the past few days (in addition to the methane and organics found), that the Curiosity rover may have found evidence for ancient microbial life itself on Mars. Specifically, microbial mats, which are common on Earth. The report comes from noted geobiologist Nora Noffke, who has been studying images sent back by the rover since it landed in 2012.
After yesterday’s exciting news about the Curiosity rover finding methane and organics on Mars, here is a reminder that the planet is rather Earth-like in other ways too, such as having water clouds and fog. This well-known image is from the Mars Express spacecraft, showing dense fog filling canyons in Valles Marineris, the giant canyon system that dwarfs Earth’s Grand Canyon. Even in Mars’ thin atmosphere, clouds and fog can still often easily form.