Comet 67P/Churyumov–Gerasimenko, or 67P, has been the focus of intense study by the Rosetta spacecraft since 2014. One of the key mysteries scientists have been trying to figure out is how the comet became the odd “rubber duck” shape that it is, with its two distinct lobes. Now they think they have the answer: Comet 67P was formed by the collision of two other, separate comets which fused together to form its distinctive shape.
In a finding that is sure to fuel the ongoing debate about possible life on Mars, NASA announced yesterday the confirmation that intriguing seasonal dark streaks running down Sun-facing slopes are indeed flows of liquid water. The water is salty (briny), but just the fact that it is current liquid water, albeit transient and in relatively small amounts, is still big news.
NASA released more new images of Pluto last Thursday, and, as has come to be expected, they are spectacular. The “snakeskin” image shows rippling terrain reminiscent of snakeskin or dragon scales, while other images show Pluto’s surface in the highest colour resolution yet. Spectral maps showing the distribution of methane ice on Pluto’s surface were also released today.
Since August 2014, the Rosetta spacecraft has been orbiting Comet 67P/Churyumov-Gerasimenko, providing an unprecedented look at an active comet as it moves closer to the Sun in its orbit. As expected, the level of activity increased the closer the comet was to the Sun, with jets of water vapour, gas, and dust becoming bigger and more prominent. The comet reached perihelion, the closest point to the Sun on its orbit, on Aug. 13, 2015. For the first time ever, a spacecraft is observing this activity close-up, as it happens. But now, scientists have been noticing other dramatic and rapid changes on the comet’s surface as well, which haven’t been explained yet.
New images of Pluto from the New Horizons spacecraft were released last Thursday… and they are spectacular. The views across Pluto’s icy mountains and plains are haunting and almost surreal, yet familiar looking at the same time. What was once only a tiny pinpoint of light in the night sky is now a complex and fascinating world, in some ways similar to our own, seen close-up for the first time ever.
Along with Jupiter’s moon Europa, Saturn’s moon Enceladus is considered to be one of the best places to look for evidence of life elsewhere in the Solar System, since both moons are now known to have liquid water beneath their icy surfaces. Now, new evidence suggests that Enceladus may be an even better candidate than first thought: data from the Cassini orbiter shows that the moon harbors a global ocean of water beneath the ice crust, just like Europa, instead of a smaller sea beneath the south pole as previously believed.
After a lull of several weeks, the downlinking of new data from the New Horizons spacecraft has begun, including stunning new images of Pluto and its largest moon, Charon, as well as a treasure trove of other scientific data. There is so much to come that it will take about one year to downlink everything from the spacecraft and send back to Earth. Those first amazing images of Pluto and its moons were only the beginning.
Wind-eroded rocks on Mars can take many different forms, sometimes resembling common earthly objects. Some good new examples include these long, thin slivers of rock which look like “spoons” and “needles,” seen by the Curiosity rover recently on sols 1089 and 1087. These fragile formations are easier to form in Mars’ weaker gravity and thinner atmosphere and can last much longer than they would on Earth – a unique form of Martian “artwork.”