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When the martian surface is eroded, pretty things emerge

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A Piece of Mars: Just like at Earth’s Grand Canyon, erosion on Mars has created some really beautiful landscapes. This 480×270 m (0.3×0.17 mi) scene shows rugged terrain that was once buried in sediment. Does the texture here represent the landscape before it was buried, or was it created in the process of scouring off all that overlying sediment? Probably a mixture of both. And we get a pretty view because of it! (HiRISE ESP_046198_1750, NASA/JPL/Univ. of Arizona)

Where we have been

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A Piece of Mars: This 0.98×0.54 km (0.61×0.34 mi) scene shows ancient windblown bedforms (maybe dunes) that have been partially eroded by the wind. The wind has left behind ghostly stripes: these are remnants of where these things once were, back when they were still actively migrating. Some of the bedforms have been almost entirely erased, except for those remaining bits. Much smaller (2-3 m wavelength) ripples have since formed between some of them, probably made from material scavenged from the larger bedforms. (HiRISE ESP_037700_1710, NASA/JPL/Univ. of Arizona)

Calling for a Better World – Remember to Vote

In English

Another attack this month, this time in Nice in the middle of the 14 July celebrations. First, the obvious: this attack, which targeted people and families watching fireworks, was despicable and inhuman. Of course, I send my thoughts to the victims and their families as well as to my colleagues and friends who live in Nice. But I am tired of being an impotent witness to this outbreak of violence everywhere in the world, and I absolutely refuse to remain silent. Like many people, I feel like I’m living a nightmare, in a polarized world in which a tiny minority of violent sociopaths want us to embrace ideas from another time whatever the cost to us, our loved ones, our values, and our dignity as human beings. I hope that this stops and that we find a solution and learn, once and forever more, to live together in peace. But we are living in a very difficult time and we must prepare for many setbacks and tragedies.

The events in Nice also make it imperative that we learn certain key lessons. We, the citizens of free nations going about our daily business, are paying a huge price for wars launched in the first decade of this century by radical and ignorant politicians who manipulated their nations into engaging in a war without end, a war that accomplishes nothing except awakening extremism and hatred in the minds of the weak, the ignorant, and the alienated. (more…)

Landslides unlike any on Earth

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A Piece of Mars: Click on this 0.96×0.54 km (0.6×0.33 mi) scene to see it in detail. Many thin, narrow landslides have formed on these dust-coated hills. As far as I’m aware, there’s nothing like this on Earth. Inside the landslide scars, there are small dusty ripples about 1.75 m (~6 ft) in wavelength, smaller than the ripples found on dark sandy dunes. These landslides are visible in images at least as far back as 2007, although they clearly formed after the small crater on the slope (which is slowly being filled with the dusty debris). (HiRISE ESP_045605_1715, NASA/JPL/Univ. of Arizona)

GPI at 2016 SPIE Astronomical Telescopes and Instrumentation

GPI is here at the SPIE Astronomical Telescopes and Instrumentation conference in Edinburgh, Scotland to talk exoplanets and engineering with our colleagues around the world. We have had talks and posters by GPIES team members on topics from AO and instruments to computing and pipelines. This week has also been a great opportunity to meet face-to-face and discuss some of the finer points of GPI technical challenges and plans going forward. Here are some pictures from the week:

Edinburgh, Scotland

Bruce gave a great talk on the GPI instrument and GPIES campaign in the instruments session:

Bruce’s talk about the GPI instrument

Vanessa gave a great talk about GPI’s AO performance in the AO session:

Vanessa’s talk about GPI AO


In her talk, I was especially struck by how well the GPI team has continued to monitor and improve the performance of the instrument, throughout the GPIES campaign.

Franck’s poster was about the GPIES project from a systems level:

Franck’s poster about the GPIES project

Marshall’s poster was about the GPIES pipeline and calibration, critical for extracting accurate exoplanet info from the raw data:

Marshall’s poster about the data pipeline and calibrations

Ben’s poster was about an improved algorithm for finding exoplanets particularly close to the star:

Ben’s poster about detecting exoplanets extremely close to their stars

Li-Wei had a poster about using the satellite spots to determine photometry in the polarized mode:

Li-Wei’s poster about calibrating the polarized photometry when using the coronagraph

Max had a poster about polarimetry mode: performance, data reduction, and contrasts:

Max’s poster about calibrating instrumental polarization and GPI’s performance in polarimetric mode

We also took the opportunity to gather 17 of the attending GPIES members for a delicious Indian dinner:

GPIES dinner on Thursday night at the conference

GPIES dinner from Franck’s perspective

I had to add this picture because Dmitry somehow managed to hide in all the dinner pictures

Unfortunately Patrick and Lyra were not able to attend the dinner due to an early bedtime for one or the other, and Stephen was only able to stop by to say hi.

After a conference like this, I always leave full of new ideas and a renewed energy for my work. Thanks GPI and SPIE for a great SPIE!

How to hide geology on Mars

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A Piece of Mars: Three things are trying to hide in this 0.96×0.48 km (0.6×0.3 mi) scene. 1) Craters are slowly being both scoured and buried by migrating sand, 2) the sand itself is hiding in the lee of crater rims and other topographic obstructions to the wind, and 3) small patches of ice (blue in this stretch) are hiding on shady slopes (north is to the right in this southern hemisphere image, taken during southern winter). (HiRISE ESP_045792_1395 NASA/JPL/Univ. of Arizona)

20 years ago, I started my nomadic life, I have no regrets

Something personal today…

Twenty years ago today, without putting too many thoughts and with the bare minimum of preparation, I left France, my native country, for an adventurous travel around the world. I had no idea where I was really going and what to expect. The 23-year old version of myself had no idea that 20 years later I will be still living abroad writing a lengthy post on a social media web site about it.

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The Triple Asteroid (87) Sylvia

Another beautiful simulation of the triple asteroid system (87) Sylvia and its two moons Romulus and Remus made in collaboration with the California Academy of Sciences.

Screen Shot 2016-06-14 at 11.48.50 PM(87) Sylvia was discovered in 1866 by N.R. Pogson, a British astronomer located in Madras, India. This main-belt asteroid is large with a diameter of ~150 km. That’s all we knew until recently.

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New craters and wind

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A Piece of Mars: The two small dark craters (2.25-2.4 m, or 7.4-7.8 ft across) are brand new, having appeared in CTX images sometime between May 2007 and April 2008. They punched through a layer of bright dust and threw up some darker material, which the wind carried downwind (near-surface winds blowing from the southwest, and higher winds blowing from the southeast). Application of an atmospheric model could further constrain the season and time of day when the impact happened, based on the prevailing wind direction. This picture from May 2016 shows the wind streaks are still there, having faded only a little in the 8-9 years since they formed. (HiRISE ESP_045798_1965, NASA/JPL/Univ. of Arizona)

Itty bitty changes: places where the wind barely moves sand

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A Piece of Mars: Not all dunes on Mars are moving at a measurable pace. This 0.96×0.45 km (0.6×0.28 mi) scene looks a lot like one I posted 3 years ago called Martian Sports. This image shows the same dunes 9.5 years apart (that’s 5 Mars Years). There are a few places where patches of sand have appeared or been removed, but it would take some detailed work to figure out whether the bulk of the dunes has shifted much. In the first post I guessed that the upper dune would crash into its topographic hurdle in 20 years, but after nearly 10 years of relative inactivity, I’ll have to revise that estimate upwards to perhaps 100 years. (HiRISE <a href="http://www.uahirise.org/ESP_045785_1995"ESP_045785_1995 NASA/JPL/Univ. of Arizona)