Curiosity is now at Dingo Gap, and the new images show the sand dunes and rocks in great detail. That includes the interesting “rock ring” mentioned earlier, just in front of the largest sand dune. Curiosity will drive right up to the sand dune (and presumably “rock ring”) in the next day or so, so even better images should be available soon!
The Curiosity rover is now getting a lot closer to Dingo Gap, that interesting opening between two rocky ledges just a short ways to the west. Small sand dunes and rocks cover the ground in DG. The image above is a beautiful panorama of DG by Olivier de Goursac assembled from several separate rover images. The image below was taken closer to DG, showing more detail in the rocks and dunes. There is also a curious little oval-shaped ring of rock just in front of the largest dune on the left side of the image; it looks similar to some of the other “bubble” formations seen previously. Is it the same or something different? We should be even closer in the next day or two to see more… See also updates here.
The Curiosity rover is going to take a slight detour to the west to cross through a gap between two rocky ledges, now nicknamed Dingo Gap (also “the chute”). The scenic feature was noticed a few days ago and there is a smooth-looking sand dune spanning the opening. Will be interesting to see up close! Then the journey southward to Mount Sharp continues…
The dwarf planet Ceres, the largest body in the asteroid belt, is releasing water vapour into space, astronomers announced yesterday. The discovery, made by the European Herschel space telescope, is being called the first unambiguous detection of water vapour around any object in the asteroid belt and was published today in the journal Nature.
Mars can seem amazingly Earth-like in many ways, and that includes weather. Bill Dunford recently posted some new images from the Mars Express spacecraft, providing some great views of Martian clouds as they drift over the landscape below. The one above is a beautiful example and all of them can be seen here. While Martian clouds don’t get as big and puffy as they can on Earth, they are still a reminder that Mars is a place, a world with its own unique history while at the same time reminding us of home.
While a lot of attention has been paid the last few days to the odd rock which “appeared” beside the Opportunity rover, the other rover, Curiosity, has found its own interesting little chunk of a Martian puzzle. While not as publicized, it has been the subject of a lot of discussion among mission followers. What are the ribbon-like bands? Could they be feldspar laths? Another type of lath? Something else entirely? Curiosity has taken Mastcam and ChemCam images, but no other information is available yet.
There is another little Martian mystery that has people talking this week – the odd appearance a few days ago of a small rock a few feet away from the Opportunity rover, it was announced yesterday during the Opportunity: 10 Years on Mars event at NASA.
The rock, nicknamed Pinnacle Island, wasn’t in images taken on sol 3528, but was in images taken of the same spot later on sol 3540. How did it get there and where did it come from?
As principal investigator for the mission, Steve Squyres, explained, the rock is whitish in colour, about the size of a doughnut with a darker spot (“jelly”) in the middle area, which has a concave or hollowed-out appearance. The finding sparked questions and theories ranging from a nugget either left there by a nearby meteor impact or deposited somehow by the rover’s wheels. Squyres thinks the wheel idea is much more likely than the random chance of a meteor happening to hit that close to the rover’s location. Are there any other possibilities?
Microscopic Imager (MI) photos have also been taken of the object and analysis so far of the darker “jelly” has shown it to be rich in sulfur, magnesium and manganese (with twice as much manganese as any other rock examined before by the rover). It is thought that the rock has been flipped over, exposing its underside.
A fascinating mystery that is sure to keep the mission scientists busy for a while.
Thanks also to Jason Major and Stuart Atkinson for use of their complementary images.
This article was first published on Examiner.com.
Three more exoplanets have just been found, adding to a long and rapidly growing list, but their location makes them a bit more unique – they orbit three different stars in a star cluster rather than other isolated stars in the galaxy, and one of those stars is a “solar twin” which is almost exactly identical to our own Sun. The results were announced yesterday, January 15, 2014, by the European Southern Observatory (ESO).
The discovery was made using the HARPS planet-finding instrument on ESO’s 3.6-metre telescope at the La Silla Observatory in Chile. The planets are located in the star cluster Messier 67, which is about 2,500 light-years away in the constellation Cancer and contains about 500 known stars.
Although thousands of exoplanets have now been found so far, only a small number of those are orbiting stars in a star cluster. Astronomers had thought that perhaps planets would be less common around stars in more densely packed star clusters, but the new results suggest that planets are probably common around stars in clusters as well, but are more difficult to detect.
According to Luca Pasquini of ESO in Garching, Germany, “These new results show that planets in open star clusters are about as common as they are around isolated stars – but they are not easy to detect. The new results are in contrast to earlier work that failed to find cluster planets, but agrees with some other more recent observations. We are continuing to observe this cluster to find how stars with and without planets differ in mass and chemical makeup.”
Two of the stars, and the one in particular, are similar to our own Sun, while the third is a red giant star. All three of the planets are much larger than Earth, with two of them having a mass about one-third that of Jupiter and the third with a mass larger than Jupiter. The first two orbit their stars in seven and five days respectively, while the third orbits in 122 days. None of them are in the habitable zone of their stars, orbiting close to their stars and therefore much hotter than Earth.
The findings indicate that many more planets may be waiting to be discovered in star clusters as well. As Anna Brucalassi of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany adds, “In the Messier 67 star cluster the stars are all about the same age and composition as the Sun. This makes it a perfect laboratory to study how many planets form in such a crowded environment, and whether they form mostly around more massive or less massive stars.”
Confirming this would be an exciting discovery, since most stars are born in similar clusters. The more they look, the more astronomers are finding planets around all different types of stars, and even free-floating planets with no star at all. To find out that they are probably also abundant in star clusters as well, may have been surprising a few years ago, but now, not so much it seems.
This article was first published on Examiner.com.
With the number of known exoplanets being discovered now numbering in the thousands (and estimated to be in the billions in our galaxy alone), astronomers have already found an amazingly diverse plethora of worlds. Some of the most common are the “super-Earths,” rocky planets which are larger than Earth but smaller than Neptune or Uranus. It has been thought by scientists that such worlds might often be true water worlds, with their surfaces completely covered by water with no land visible at all, causing less stable climates than on our home planet.
But now new studies suggest that these planets might tend to be more Earth-like after all. Two scientists, Nicolas B. Cowan from Northwestern University and Dorian Abbot from the University of Chicago have announced a new model for super-Earths which shows that ones which are tectonically active would probably store most of their water in their mantles, producing both oceans and continents and subsequently a more Earth-like climate. This would likely be true regardless of the mass of the planet(s).
As Cowan explains:
“Are the surfaces of super-Earths totally dry or covered in water? We tackled this question by applying known geophysics to astronomy.
Super-Earths are expected to have deep oceans that will overflow their basins and inundate the entire surface, but we show this logic to be flawed. Terrestrial planets have significant amounts of water in their interior. Super-Earths are likely to have shallow oceans to go along with their shallow ocean basins.”
Plate tectonics allow a water cycle to exist between the oceans above and the mantle below, which helps to stabilize the climate. Even for such rocky planets larger than Earth, this could still create both oceans and continents, due to increased gravity and seafloor pressure.
“We can put 80 times more water on a super-Earth and still have its surface look like Earth,” Cowan said. “These massive planets have enormous seafloor pressure, and this force pushes water into the mantle.”
On Earth, the carbon cycle, essential for life as we know it on our planet, is also regulated by surface temperatures, producing a stabilizing feedback, a sort of thermostat on geological timescales.
As Abbot notes, “Such a feedback probably can’t exist in a waterworld, which means they should have a much smaller habitable zone. By making super-Earths 80 times more likely to have exposed continents, we’ve dramatically improved their odds of having an Earth-like climate.”
The findings suggest that super-Earths are much more likely to have an Earth-like surface than previously thought. The new model depends on these planets have plate tectonics and a similar amount of water, or more, stored in their mantles, which are still two unknowns at this point. But the odds are probably good that at least some of them will, increasing the chances of life of some sort on these worlds.
The findings were presented on Jan. 7 at the 223rd meeting of the American Astronomical Society (AAS) annual meeting in Washington, D.C.
This article was first published on Examiner.com.
Here are a couple of new images taken by the Chinese Chang’e 3 lander and Yutu rover on the Moon. Much better resolution than the first earlier images and nice to finally have some new views from the lunar surface after all these decades! An interesting change from the Mars rovers, which look at a bright, dusty Martian sky, while here there is virtually no atmosphere and perpetual blackness overhead…