So-called “waterworlds” have been found to be surprisingly common in the Solar System – small icy moons which have ice crusts but oceans of liquid water below the surface. These include Jupiter’s moons Europa and Ganymede and Saturn’s moons Enceladus and Titan, and possibly others. These moons are cold and very far from the Sun, but heated inside by the gravitational pull of their giant host planets and/or radioactivity. Now there’s another Solar System body which, even more surprisingly, some scientists think has a subsurface ocean: Pluto.
NASA’s current rovers, Curiosity and Opportunity, are continuing to explore their respective regions of Mars, with new findings that are providing yet more clues as to the geological history and potential past habitability of this fascinating world. They have also both just completed significant steps in their journeys and are now entering new and exciting phases of their missions. Both missions have found yet more evidence that the Mars we see today – cold and dry – was once much wetter and potentially habitable, at least for microorganisms.
Sending human astronauts to Mars is a dream shared by many, but there are still challenges to overcome and the question of just how to accomplish it is a subject of intense debate. Some supporters advocate sending a mission directly to Mars, while others think that returning to the Moon first, for potentially beneficial training, is the way to go. Indeed, former astronaut James Lovell, who flew on two trips to the Moon, has also called for a return to the Moon first. NASA itself has stated its desire to send a crewed mission to a nearby asteroid first, instead of the Moon, going a bit farther into space than the Moon as its idea of preparation for the much longer journey to Mars. A major problem has been that NASA has still not set a firm timetable for such a mission; it wants to go to Mars, but the steps to achieving that goal are still unclear.
The New Horizons mission to Pluto has been nothing less than incredible, giving us our first close-up views of this enigmatic dwarf planet and its moons. But the show isn’t over yet, as the New Horizons team is now planning for its next encounter with another Kuiper Belt Object (KBO) in 2019. But even before then, the spacecraft has been busy observing other smaller objects, and has now collected the first science data on one of them, called 1994 JR1.
For several years now the Kepler Space Telescope, as well as other telescopes, has been discovering an increasing number of exoplanets, with over 2,000 such confirmed worlds found so far (and nearly 5,000 candidates). Today, NASA announced that the Kepler mission has added 1,284 newly confirmed exoplanets to that list, vastly increasing the number of known planets orbiting other stars. This is the largest number of new planets ever announced at one time. The new results were announced during a NASA teleconference briefing.
Mars’ atmosphere is thin and cold, composed primarily of carbon dioxide along with other trace gases and some water vapour. Evidence has continued to mount, however, that the rarified atmosphere we see today once used to be much thicker and possibly warmer, making it potentially more life-friendly early on. Just how thick and how warm is still a subject of much debate, but there is also another interesting aspect to all of this: New evidence from the Curiosity rover has shown that the Martian atmosphere also used to have a lot more oxygen in it than it does now. Today, only very small traces of oxygen can be found, as opposed to Earth’s oxygen-rich atmosphere. So what does this mean? Could there be biological implications?
The New Horizons mission has revolutionized our understanding of Pluto and its moons, after conducting the first-ever flyby last summer. These mysterious worlds were finally seen up close, and this new view created as many, if not more, new questions as it answered old ones. While the flyby may be long over now, the spacecraft itself is still in excellent health and continues to plunge deeper into the Kuiper Belt at the outer fringes of the Solar System. Scientists have been eager for New Horizons to continue exploring this region farther out past Pluto, and now a proposal has been formally submitted to NASA to do just that. This extended mission will conduct a flyby of at least one more Kuiper Belt Object (KBO) and last until 2021.
This image shows the stars Alpha Centauri A and Alpha Centauri B just above the edge of the cloud tops in Saturn’s atmosphere, as seen by the Cassini spacecraft. The two stars are part of the Alpha Centauri triple star system, which is the closest star system to our Solar System, but is still almost 30,000 times farther away from us than Saturn is.
The Cassini spacecraft has been orbiting Saturn for many years now, studying the massive planet and its moons in unprecedented detail. Now, Cassini might be able to help shed light on another Solar System mystery: the possible existence of a ninth planet in the outer Solar System far past Pluto, or “Planet Nine” as it has been dubbed. There is also a new report, based on old data, that the Huygens lander observed methane ground fog as it descended to the surface of Saturn’s moon Titan in 2005.
Almost, but not quite… the Opportunity rover is now driving to another area on the hillside where it is currently located, after attempting to reach a difficult rock target. The rover wasn’t quite able to get close enough to the target to conduct further studies, after driving on the steepest slope ever encountered by any rover so far, on Knudsen Ridge.