Fuzzy dunes
Published 1/2/2018 in Lori Fenton's Blog Author lfenton
A Piece of Mars: The dunes (or maybe they're ripples) in this valley appear to be fuzzy (the view is 625x775 m, 0.39x0.48 mi). They're not really fuzzy, but it's not actually clear what's going on. They seem to have smaller ripples superposed on them, and maybe bright dust has settled into the troughs between ripple peaks, so that they take on a striped, feathered look. It's unlike anything I've seen on Earth. (HiRISE ESP_052776_1785, NASA/JPL/Univ. of Arizona) read more ❯

Buried by ejecta
Published 12/26/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: To see this one well you'll have to click on the image. At the lower right, a 240 m (787 ft) diameter crater formed when a bolide hit the surface, throwing out ejecta on the surrounding terrain. Zooming in, you can see that the ejecta has a distinctive rough surface. Farther from the crater there are smooth patches where ejecta didn't fall. What I like about this is the many small bedforms (ripples), some of which are covered by ejecta and some of which aren't. Closer to the crater, you don't see so many of these bedforms because the ejecta is thick enough to have buried them. The crater itself is fairly "young" for a geologic feature on Mars, but enough time has passed to allow small bedforms to accumulate inside it (ripples like these don't form overnight). (HiRISE ESP_052794_1545, NASA/JPL/Univ. of Arizona) read more ❯

The mysterious bright streaks
Published 12/18/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: Some things just go unexplained (so far, anyway). Here's a mysterious bright streak (scene is 1.2x1.8 km, 0.75x1.12 mi) concentrated between two sets of ripple-like bedforms. It looks sort of like a river, but it's on flat terrain and it's not water. It's part of a larger set of bright streaks that you can see throughout the top of this broader CTX image (the bright streak shown in detail here is visible as a distinct white stripe on the floor of a crater). My guess is that at some point, probably at least several million years ago, a bunch of fine bright silt was blown towards the north-northwest, settling in a few places. I'm guessing it's silt (finer-grained than sand) because it didn't form dunes, and it's not as fine as the clay-sized dust that blows into dust storms because this stuff wasn't completely blown away... read more ❯

Dunes in a row
Published 12/11/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: Look at the alignment of the ~100 m dunes in this 713x750 m (0.44x0.47 mi) scene. How do dunes form in such straight lines? And why don't they always do that? It's likely that these dunes were once long ridges stretching from the lower right to upper left. The shape of the slip faces suggests they're formed from two winds that blow from similar directions, both of which push sand toward the upper left. To stay stable, this sort of dune needs a constant influx of sand from upwind (from the lower right), but if that flow of incoming sand lessened, then a long dune would be forced to break up into a series of smaller dunes. That may be what's happened here. Check out the whole image, and you'll see other long ridges that haven't yet broke up into smaller dunes. (HiRISE ESP_052798_2565, NASA/JPL/Univ. of... read more ❯

Ripples of rock
Published 12/4/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: To the upper right of this 0.85x0.6 km (0.53x0.37 mi) scene is a flat-lying plain strewn with large ripples. To the lower left is a rugged hill with gray rock laced with white veins (this might be part of an impact megabreccia identified nearby in Holden crater). Notice that some of the ripples on the rugged hill are also veined - this is evidence that they are actually eroded into the bedrock, rather than fine-grained deposits like their counterparts on the plain. It's not yet clear how these "Periodic Bedrock Ridges" form, and they may be unique to Mars. (HiRISE ESP_052789_1520, NASA/JPL/Univ. of Arizona) read more ❯

Athena Coustenis, Full Curriculum Vitae
Published 11/27/2017 in Athena Coustenis Author Athena Coustenis read more ❯

The corpse of a dune
Published 11/27/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: The rippled darker patch in this 600x600 m (0.37x0.37 mi) scene is the former site of a sand dune. This is one of a few "dune corpses" found just upwind of a dune field in Holden crater. The dunes are migrating to the south and east - you can see that the arc of this former dune opens to the south, the way a barchan slip face would. This dune is what's left behind after most of its sand has migrated downwind. (HiRISE ESP_052367_1540, NASA/JPL/Univ. of Arizona) read more ❯

List of publications
Published 11/26/2017 in Athena Coustenis Author Athena Coustenis read more ❯

Intriguing pair of satellites caught with the eVscope
Published 11/23/2017 in Franck Marchis Blog Author Franck Marchis
If you often look at the evening dark sky in a clear area far away from the city, you have probably seen a speck of light which moves with respect to the star, that's probably a distant satellite that shines because it reflects the light of the sun at high altitude. According to NASA's Orbital Debris Program office, there are an  about 21,000 large debris (>10 cm) and satellites orbiting around Earth right now, so much more than you can see with your naked eye. The eVscope is designed to pinpoint and image Deep Sky Objects (nebulae, galaxies), but we have already shown its potential to observe dwarf planet like Pluto, as well as asteroid like Florence. Because the telescope can image targets as faint as those astronomical bodies, we thought that it will also be able to image small satellites and debris as well passing serendipitously in the field of view. This is what... read more ❯

1,500th telescope on our Kickstarter. Thank you!
Published 11/21/2017 in Franck Marchis Blog Author Franck Marchis
We have just passed the pledge of our 1,500th telescope on our Kickstarter campaign. With such an amazing number of eVscopes soon to be in operation around the planet, our Campaign Mode and Citizen Science applications will be extraordinary exciting and revolutionary! Your support has brought us to this truly amazing moment, and all we can say is thank you. After so many questions about planets and requests for additional photos, we felt the need to conduct new observations—and despite bad weather in parts of the Northern Hemisphere, we managed to do it! As you check out these pictures, please keep in mind that what you see through the eVscope’s eyepiece is far more beautiful and mind blowing. The image quality and observing experience there are definitely superior to what you see in these photos. The eVscope provides truly amazing astronomical views when pointed at nebulae and galaxies. As you can imagine,... read more ❯

Is it windblown or not (#2)?
Published 11/20/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: This 0.93x1.25 km (0.57x0.78 mi) scene shows what I'm starting to think are windblown features. I posted something similar to this once before, from a location not that far from here. In this one region of Mars there are parallel lines cut into the tops of hills. A geologist would first presume they were exposed, tilted layers. But the regularity of their spacing (especially when you zoom in) is a bit unusual, and suggests some sort of self-organization (like windblown ripples). And then the questions begin: why just in this spot on Mars? what's unusual about the rocks (or the wind) here? I still have no good answers. (HiRISE ESP_052386_1565 NASA/JPL/Univ. of Arizona) read more ❯

Published 11/15/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: There's a fabric of erosion in this 1x1 km (0.62x0.62 mi) scene, with the main wind blowing from lower right to upper left (and if you look carefully you'll see there's a second, subtler fabric a bit clockwise from that one). The result is a landscape strewn with streamlined rock called yardangs. The darkest areas are shadows from rock faces scoured by the wind so deeply that they've been undermined until there's overhang. Normally this would lead to collapse features, like rock piles, but you don't see those here. That's an indication that the rock here is easily eroded and fine-grained, so that as it's eroded, it's simply carried off by the wind. (HiRISE ESP_052384_1800, NASA/JPL/Univ. of Arizona) read more ❯

Unistellar Signs Up More Than 1,200 Early-adopters for its Revolutionary eVscope Confirming the Public Interest for Citizen Science Astronomy
Published 11/9/2017 in Franck Marchis Blog Author Franck Marchis
Unistellar Signs Up More Than 1,200 Early-adopters for its Revolutionary eVscope Confirming the Public Interest for Citizen Science Astronomy San Francisco & Marseille, November 9, 2017. Unistellar, a startup that’s committed to restore the joy of night-sky viewing to people all over the globe, is off to a strong start thanks to the massive success of its recent Kickstarter campaign. The campaign gave supporters the opportunity to order an eVscope, a revolutionary, electronics-based telescope that offers unprecedented views of distant objects in the night sky. The device also allows users to make significant contributions to science by joining observing efforts led by prominent astronomers. “After three years of prototype development, building, and testing, we were proud to bring our compact, intelligent, and powerful telescope to market,” said Arnaud Malvache, President and CTO of Unistellar, located in Marseille. “Our team also demonstrated the prototype at several star parties in Europe and the USA, and... read more ❯

Island in the stream
Published 11/8/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: In the floor of what might have been an old fluvial channel there are a bunch of really neat dunes (or maybe ripples, they're TARs and we don't know yet what they are). One spire pokes up here, ~200 m (656 ft) across and ~90 m (295 ft) tall. The TARs reveal the wind direction here, as wind flowed from top to bottom around the spire, converging on the lee side. (HiRISE ESP_026557_1525, NASA/JPL/Univ. of Arizona) read more ❯

A few more pictures of astronomical targets seen with the eVscope
Published 11/8/2017 in Franck Marchis Blog Author Franck Marchis
We got a lot of requests for additional pictures of astronomical targets taken with the eVscope. Here some of them taken recently. One nebula, one galaxy, one planet in our solar system and our moon.... Enjoy!                 read more ❯

Black and tan
Published 11/6/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: Dunes in the top row in this 0.73x0.47 km (0.46x0.29 mi) scene are dark but those in the lower row are brighter. Why? They're all probably made out of the same kind of sand, which is dark. And they all probably got covered by fine-grained airfall dust, which is bright. At some point after that, a wind blew, probably from top to bottom of the view, and moved enough sand to kick off the fine bright dust. But the relief from those top dunes took energy from the wind, so that by the time it reached the lower row, it wasn't strong enough to move sand anymore. So until the next windstorm, we see two different colors of dunes. (HiRISE ESP_052399_1885, NASA/JPL/Univ. of Arizona) read more ❯

Seeing the long-period Comet C/2017 O1 with the new eVscope
Published 11/3/2017 in Franck Marchis Blog Author Franck Marchis
You’ve probably heard of C/2017 O1, a long-period comet that’s now paying what may well be its first-ever visit to the inner solar system. Earlier this month we decided to check it out using our eVscope prototype. The All Sky Automated Survey for Supernovae (ASAS-SN) system discovered Comet O1 ASAS-SN (now officially named C/2017 O1) on July 19, 2017, when it was in the constellation Cetus and had only a faint 15.3 magnitude. Even at that dim magnitude, however, an eVscope pointed at this area of the sky could have detected it. A few days later, however, as it came closer to the sun and its activity increased, the comet shot up one hundred fold in brightness to magnitude 10. Our prototype eVscope spotted the object from Aubagne, France on October 16 as the comet was moving from the Perseus... read more ❯

Mars' corduory
Published 10/30/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: The wind on Mars likes to make textiles (unfortunately the term geotextiles is already taken for other purposes). This 1x0.6 km (0.62x0.37 mi) scene shows two different sets of ripples. The larger set has straight to wavy crests, and they're ~18 m (~59 ft) apart, which is pretty big for ripples (really they're TARs). Inbetween those (click on the picture so you can see them) are small ~2 m (~6.5 ft) ripples that make Mars look like it's made of kahki corduroy (which is a thing but it's not on trend, so Mars could stand to catch up a little). What does this all add up to? There are at least two different sets of wind directions, and each probably formed on its own timescale. If we learn how to decipher these, then we could better understand weather patterns on Mars, because ripples like these are... read more ❯

It’s Official! The eVscope from Unistellar Gets Kickstarted
Published 10/28/2017 in Franck Marchis Blog Author Franck Marchis
Marseille, France & San Francisco, CA – October 25, 2017 – Imagine being able to see galaxies, nebulae, and asteroids and discovering the sky from your own backyard while participating in scientific investigations. Unistellar has launched a Kickstarter campaign for its eVscope, a powerful telescope that will give the sky back to all of us. The Unistellar eVscope was first presented at the CES in 2017 and recently won the Innovation Award in the Tech For a Better World product category for the CES 2018. During the summer 2017, the Unistellar team has shown the telescope capabilities to thousands of people in Europe and in the United States.  It has since received astonishing reviews and comments. The Unistellar team has worked for 2 years to perfect their idea, building and testing several prototypes to finally create a compact, intelligent and powerful telescope that can be carried everywhere and which is easy to use. Using its... read more ❯

Just do it
Published 10/23/2017 in Lori Fenton's Blog Author lfenton
A Piece of Mars: It's all about wind scour here in this 0.75x0.75 km (0.47x0.47 mi) view. The big "swoop" is an erosional channel dug into the surface by winds (blowing from the lower left) trying to erode the hills in the center. But notice that the hills are all aligned to the upper left/lower right, like a school of fish swimming the same way). That alignment tells us there's a second wind that came along later, blowing (I think) from the lower right. That wind also left behind some ripples (TARs, really) that swirled around the older big "swoop" channel. (HiRISE ESP_016372_1975, NASA/JPL, Univ. of Arizona) read more ❯