Hills, boulders, and wind
A piece of Mars: In the lower left of the image, a small hill stands above a plain partly covered by stabilized ripples. Boulders have rolled down the hill as it slowly erodes. If these ripples aren’t ever activated by the wind again, they will one day be completely buried by sediment eroded from this and other surrounding hills. (HiRISE ESP_031215_1830, NASA/JPL/University of Arizona)
- aeolian | burial | erosion | ripples | stabilized
Astronomy is not only about the study of stars, the search for exoplanets, the characteristics of detectors, and the size of telescopes, it is also about human interactions. While digging through my old email for a document, I found this group picture that was taken during our first GPI Science meeting at University of California at Berkeley in 2007.

Group picture from the GPI Kick-off meeting (March 2 2007). back row, from left to right: M. Perrin, XXXXX, C. Marois, R. Doyon, M. Shao, J. Graham, G. Marcy, G. Serabyn, L. Palmer, J. Wright, J. Jensen. On the front row, from left to right: F. Marchis, P. Kalas, B. Macintosh
Blue ribbon
A piece of Mars: In ancient, wind-carved hills, a bluish ribbon of actively moving sand still winds its way. It is a remnant of a long-lived period of wind scour that shaped this landscape. (And it’s been stretched to look more blue than it really is — it’s really more of a dark gray.) (ESP_030932_1750, NASA/JPL/University of Arizona)
The colors of geology
A piece of Mars: Here in the bottom of a crater in Coprates Chasma is the intersection of two sets of ripples: dark, dust-free ripples at the bottom of the crater, and lighter ripples formed from debris that has come down the rim of the crater. (HiRISE ESP_030927_1675, NASA/JPL/University of Arizona)
THE FOLLOWING ITEM WAS ISSUED BY ASTRONOMY MAGAZINE IN WAUKESHA, WISCONSIN, AND IS POSTED ON MY BLOG FOR YOUR INFORMATION.
29 May 2013
This release is based on a story in the June 2013 issue of Astronomy magazine: http://www.astronomy.com/~/media/Files/PDF/Magazine%20articles/ET-with-infrared-light.pdf
Until recently, one of the ultimate mysteries of the universe — how many civilizations may exist on planets orbiting other stars in the Milky Way Galaxy — relied on the possibility of detecting intelligent beings by radio signals. Now a team of astronomers, engineers, and physicists from the University of Hawaii, the University of Freiburg, and elsewhere has proposed a new and powerful technique to search for intelligent life.

Artistic rendering of the Colossus telescope, a 77m wide telescope capable of detecting the near-infrared light resulting from a technologically advanced civilization living on an exoplanet located at 60 light-years. (c) http://www.innovativeoptics.ca/
Where does martian sand come from?
A piece of Mars: The source of dune sand on Mars is normally something of a mystery. But here on the interior wall of a small crater it appears that small gullies have eroded sediment from the wall and carried it down toward the center of the crater (toward the upper right). The bluish and tan regions are the material the gullies have transported, and the bluish sediments have formed into small aeolian ripples. The mystery is solved for this one small region of Mars: is it the same story elsewhere? (HiRISE ESP_030915_1290, NASA/JPL/University of Arizona)
New WISE data release
WISE has released a new dataset. It is a re-processing of the data taken from 1 Oct 2010 to 1 Feb 2011 after all the hydrogen coolant was gone. During this “warm” WISE period only the 3.4 and 4.6 micron channels worked. A preliminary version of this data using the “cold” WISE calibrations and point spread functions was released earlier. This new version uses calibrations and PSFs based on the warm WISE data.
New dust devils swirls
A piece of Mars: Swirly loops form on the martian surface as dust devils pass by, cleaning up dust on the surface and revealing the dark, rippled dune beneath. Every year the swirls get cleaned off and reform — such patterns are known to occur in only a few select places on Earth, but they are common on Mars. (HiRISE ESP_031199_2070, NASA/JPL/University of Arizona)
- aeolian | dunes | dust devil | ripples
Apocalyptic weather on Paranal
As some would say: “the Winter is coming…”
This is unusual to get such dark and threatening clouds above one of the driest place on Earth. But it’s been so for two days and we just hope that no drops of rain will fall down because the Observatory is not made for rain and that’s just more hassle for the staff and of course for the occasional visitors who are not getting their projects done.
Tonight it got worse, the wind is blowing over 20 meters/second (45 miles/hour) and the humidity rose above 50% due to the proximity of the clouds.
In the morning it did look promising though… I really like this metallic light and feeling we get just before sunrise (not much sun today). The horizon was so clear, we could see the snow on the Cordillera a few hundred km away as well as on the 6739m (21,300 ft) Llullaillaco Volcano which is in Argentina.
But the Observatory routine (and life!) does not stop. The cleaning ladies walk towards the residencia…
At night, after a rough day of work taking care of all the instruments and facilities some French engineers play with their “toys for boys”: they fly helicopters in the gym!
At the end of the night, the scenery is impressive. Here’s a long exposure shot above the Residencia at 6:00am. we can see the Southern Cross making its way through the moving clouds and the important airglow. The night isn’t completely lost, at least for me!
You can see more photos about the past 48 hours of cloudy Paranal on this Flickr Photo Set.

Roger shoots
Dunes on crater bones
A piece of Mars. The dark circle (~170 m across) in the middle of the picture is the interior of what used to be a crater. It’s now almost completely eroded away, probably by the wind. Small dunes have formed on these former crater sediments — because the dunes seem to form mostly on this circular plateau, it’s likely that they’re made from sand derived from the former crater sediments (and thus these dunes have not traveled far). (HiRISE ESP_030622_2060, NASA/JPL/University of Arizona)
- aeolian | erosion | Gale crater | ripples





