Welcome to Cosmic Diary

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)

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.

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)

As some would say: “the Winter is coming…”

Threatening clouds over Paranal Observatory

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.

night is over, clouds are there

But the Observatory routine (and life!) does not stop. The cleaning ladies walk towards the residencia…

Usual morning walk from the “village” to the Residencia, under the unusual clouds.

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!

Sebastien Poupar flying his helicoper

Pierre Bourget tuning his big helicopter

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!

Entering a cloudy twilight, back to the Residencia!

You can see more photos about the past 48 hours of cloudy Paranal on this Flickr Photo Set.

Roger shoots

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)

Scientists report on identification of clays and carbonate that formed on early Mars in a liquid water environment near a large impact basin. Coordinated analyses using multiple datasets were used to characterize the composition and stratigraphy of the region. A paper published online in April 2013 in the Journal of Geophysical Research highlights new mineralogic and geologic observations at a site called Libya Montes just south of the Isidis Basin on Mars. “Liquid water is likely to have been present on the surface or subsurface of this region when the clays and carbonates formed” says Janice Bishop, SETI Institute scientist and lead author on the paper.

(more…)

A piece of Mars: Everybody else loves this image because it shows an inverted channel — the remains of a stream that once flowed through this area. But I love it because the little dunes were also formed by a flow. The flow of the wind, that is. Here the wind is deflected by the former streambed, forming dunes that moved in the same direction (lower right to upper left). (HiRISE ESP_030609_1550, NASA/JPL/University of Arizona)

A piece of Mars: Is it modern art? Well maybe it looks like it from a distance. Up close, this is reality on Mars. These are dark dunes in the southern hemisphere, awaking from a long hibernation beneath bright winter frost (a touch of which can still be seen in white patches). The wind has begun to shape the dunes, leaving crayon streaks where dust devils have swept by. Maybe we’ll see those little ripples move this summer. (HiRISE ESP_030602_1080, NASA/JPL/University of Arizona)

Adapted from MESSENGER Mission News (March 26, 2013)

The International Astronomical Union (IAU) — the arbiter of planetary and satellite nomenclature since its inception in 1919 — recently approved a proposal from the MESSENGER Science Team to assign names to nine impact craters on Mercury. In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after famous deceased artists, musicians, or authors or other contributors to the humanities.

Global map of Mercury recently released by the NASA Messenger team. The globe on the left was created from the MDIS monochrome surface morphology base map campaign. The globe on the right was produced from the MDIS color base map campaign. Portraits of the nine artists, musicians and authors honored with the name of a crater on the planet. (adapted from NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington & Wikipedia by F. Marchis)

(more…)

A piece of Mars: There are vast plains on Mars that display criss-crossing streaks like this. These are ~5 m (~16 feet) across, give or take. Did an alien drive a dune buggy all over, leaving behind tracks? Nope. These are the distinctive trails made by the passage of dust devils, which act like huge vacuum cleaners that suck up dust from the ground. The patterns of the tracks change every year as new dust devils churn away at the surface. (HiRISE ESP_030916_1250, NASA/JPL/University of Arizona)