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.
- Comments Off
- Tweet This !
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.
- Comments Off
- Tweet This !
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!
A piece of Mars: This scene (3.9×2.5 km or 2.4×1.6 mi) shows a surface carved by two different winds: one blowing from the right and one blowing from the bottom right. They’ve formed overlapping sets of streamlined rocks called yardangs. Can you tell which set of yardangs was formed first? It’s a little more complicated than it may first appear. (HiRISE ESP_037156_1800 NASA/JPL/Univ. of Arizona)
A piece of Mars: The two shadowed hills in the upper part of this frame (497×373 m or 1631×1224 ft across) rest on a flat plain covered in large ripples. On the plain the ripples are aligned north-south, formed perpendicular to a wind blowing from the east (right). But those hills block the wind and turn it, so that the ripples between the hills change direction. This is how windblown landforms can be used as wind vanes in remote places (like on Mars). (HiRISE ESP_037188_1835, NASA/JPL/Univ. of Arizona)
A piece of Mars: Dunes outside the crater are straight but the ones inside the crater look like a spiderweb. Why? This image shows just how much the topography of a crater wall can affect the wind, which produces a much more complex set of dunes inside than out on the plains. (HiRISE ESP_037195_1625 NASA/JPL/Univ. of Arizona)
These two papers by J.T. Wright’s group were posted today on astro-ph
The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. I. Background and Justification
J. T. Wright, B. Mullan, S. Sigurðsson, M. S. Povich
The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result
J. T. Wright, R. Griffith, S. Sigurðsson, M. S. Povich, B. Mullan
Based on the analysis of WISE and Spitzer data, the authors concluded that “Kardashev Type III civilizations (a civilization that extracts fusion energy, information, and raw-materials from multiple solar systems) are very rare in the local universe”.
I remind you that we had a SETI hangout on this topic with this group, including as well Jill Tarter and Freeman Dyson in September 2013.
I look forward to reading about the search for Kardashev Type II civilizations from the same set of data.