The Solar System is full of surprises. Mercury, the planet closest to the Sun, is a baking hot world, as would be expected. It is one of the last places where you would think anything would or could be frozen, but things aren’t always as they seem. There has been tantalizing evidence already for water ice deposits in craters at Mercury’s north pole, and now the MESSENGER spacecraft in orbit around the small planet has visually confirmed it for the first time.
Many different kinds of exoplanets have been found by astronomers, from giant “hot Jupiters” and “super Earths” to smaller rocky worlds like Earth or Mars. Now, another type has been discovered, an “ice giant” similar to Uranus or Neptune in our own Solar System. The planet is about 25,000 light-years away in the constellation Sagittarius and is one of the first found that appears to be similar to the ice giant planets in our Solar System, Uranus and Neptune, which are part gas and part ice in composition. The discovery was made by an international team of astronomers, led by Radek Poleski, a postdoctoral researcher at Ohio State University.
The Rosetta spacecraft has taken another “selfie” photo with the comet 67P/Churyumov-Gerasimenko in the background. Rosetta was only 16 kilometres (10 miles) from the comet at the time.There is even a jet clearly visible, emanating from the “neck” region of the double-lobed comet!
Being able to find exoplanets orbiting distant stars is a major accomplishment in itself, and fine-tuning the data enough to discover details about the characteristics of those planets is quite another. Not an easy task. Astronomers have had some initial success, but now they have been able to create the most detailed weather map for any exoplanet so far.
A new image from the Rosetta spacecraft, using the high-resolution OSIRIS camera, of a huge boulder on the surface of the comet. The boulder is about 45 metres (147 feet) across and named Cheops, after the largest pyramid at Giza in Egypt. In the wider view image below, it is the largest boulder near the centre of the photo.
A great image from the Lunar Reconnaissance Orbiter, showing the Earth, and, far in the distance, Mars, which looks like a very tiny speck where the label is near the top of the image. Click on image to zoom in. Mars is much farther away than the Moon! A significantly larger version of the photo is available here.
Titan is the only moon in the solar system known to have a dense atmosphere, and while similar to Earth’s atmosphere in some ways, such as being rich in nitrogen, it also holds surprises for planetary scientists. Analysis of data from Cassini of a huge cloud which hovers over the moon’s south pole shows that it is both toxic and colder than expected.
A beautiful new image of Mars taken from orbit by India’s Mars Orbiter spacecraft. Clouds, dust storms and the mottled surface of the planet itself can all be seen in this view. Thanks to Ted Stryk for colour enhancement of original ISRO image. More information about the Mars Orbiter mission is available here.
As the Curiosity rover was approaching the flat rock outcrop called Pahrump Hills, where it is currently drilling again, it spotted a few more interesting features. These include the “ball,” a small round spherical stone, about a cm or two across, which resembles the “blueberry” concretions seen by the Opportunity rover in Meridiani (like the ones in the image at the top of the blog sidebar). The Meridiani ones were all over the place though, while this one seems to be all by itself.