A piece of Mars: This looks like a pair of eyes looking at us. It’s really some small brown hills, two of which (the “eyes”) are surrounded by dark gray sand that has blown into scours as the wind interacts with the topography of the hills. It’s a great way to tell what direction the strongest winds blow here: from the bottom to the top of the frame (the frame is 509×382 m or 1670×1253 ft). (HiRISE ESP_037995_1755, NASA/JPL/Univ. of Arizona)
A Piece of Mars: This field of 2 m wide sand ripples has a dark splotch in the middle (the scene is 300×225 m or 984×738 ft). The splotch is the peak of a low hill that straddles the classification gap between proper dunes and simple drifts of sand. Maybe it was a dune that has been modified down to this bump, or maybe it’s a drift that could grow into a dune, if enough sand blew in and accumulated on it. (HiRISE ESP_038117_1385, NASA/JPL/Univ. of Arizona).
A piece of Mars: These funny shaped dunes were formed by winds blowing from two directions – one from the top of the frame and one from the upper right. Both winds make steep slopes (slip faces) on the downwind (lee) sides of the dunes. With enough sand supply, the “point” between the slip faces will continue to extend toward the lower left as the two winds take turns driving the sand back and forth. (HiRISE ESP_037203_2555, NASA/JPL/Univ. of Arizona)
A piece of Mars: There are two sets of ripples here: tan ones and gray ones, each oriented to a different wind (scene is 300×225 m, or 984×738 ft). The gray ones sit on top of the tan ones, so the gray ones are younger. Now come the fun questions: why the different colors? Are they made out of different material (and if so, why), or are the older tan ones different because the gray sediment has weathered to tan over time? (HiRISE PSP_002387_1985, NASA/JPL/Univ. of Arizona)
A piece of Mars: Wind flow on Mars can be quite dramatic. Here, a single wind-sculpted hill stands 1.5 km (0.93 mi) wide and 600 m (1970 ft) high (color shows elevation). That sounds big, but vastly larger is the volume of material that has been removed to form it. A sandy ridge forming a “bow shock” indicates present-day winds still blow in the same direction. (HiRISE ESP_017173_1715, NASA/JPL/Univ. of Arizona)
This week was the fourth commissioning run for GPI and I was happy to be back at Gemini to help. When we arrived it was a little cloudy, but just as beautiful as I remembered.
This week predicted an unfavorable forecast; the first several nights battled cloud cover and high winds, which meant a lot of engineering tests and fewer opportunities to actually look at the sky. Clouds make for some really fantastic sunsets, though.
With a the storm rolling in last night with high winds we were unable to open the dome. We stayed over night with the hope of bright eyed astronomers that it would not snow and we would have clear skies for Saturday. In the morning we woke up to a winter wonderland.
Every so often our own planet reminds us to take a break from work and build a snow..thing.
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Yesterday the U.S. House of Representatives Subcommittee on Space held a hearing entitled “Exploring Our Solar System: The ASTEROIDS Act as a Key Step Planetary science“. I was curious about this act and expected the hearing to focus on interesting new ways to motivate private companies to design, launch, and operate space missions, and further the study of our Solar System.
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A piece of Mars: The swirly candy stripes in these big dark dunes are layers inside that have been made visible by wind erosion (the scene is 1.5×0.9 km, or 0.93×0.56 mi). It’s rare to see the inside structure of dunes like this, but these are being eroded by wind blowing from the upper right. For similar examples on Earth, check out The Wave. (HiRISE ESP_037200_1765, NASA/JPL/Univ. of Arizona)
A piece of Mars: This scene (509×382 m, or 1670×1253 ft), aside from showing some lovely rippled dunes, has many car-sized boulders in it. Some are surrounded by ditches in the sand, like little moats. Why? The sand is blown away from the ground as wind impacts the rocks. My colleague Mark Bishop has studied these in more detail (read more here) (HiRISE ESP_037201_2450, NASA/JPL/Univ. of Arizona)
SPHERE, the extreme adaptive optics facility, high contrast imager spectrograph and polarimeter of the Very Large Telescope, is now offered to the community for P95 (April-Sept 2015, please look at the Call for Proposals). It has unique capabilities that make it a fantastic high-resolution, high-contrast disk imager with a field of view up to 11″ (much bigger than most of its main competitors). Material is available online to help you write your proposals.
SPHERE can lock its AO on fainter stars than GPI, up to R=11 for service mode and up to R~15 in visitor mode (with degraded AO performances of course). This is interesting for low-mass stars! Nevertheless, and unlike for NACO or SINFONI, the AO star must always be on-axis.
SPHERE can also observe in visible light thanks to its imager/polarimeter ZIMPOL and access resolution of the order of 20 milliarcseconds thanks to its high order (over 1300 actuators deformable mirror) adaptive optics system SAXO.
Let’s congratulate the whole SPHERE consortium and ESO staff involved since many years with such a novel, complex but working instrument!