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Ancient ripples?

A Piece of Mars: Potential signs of wind activity are everywhere on Mars. Take this 0.96×0.54 km (0.6×0.34 mi) scene, which is on bedrock dated to be several billion years old. There’s a fabric of ridges trending from the upper right to lower left. The smaller and smoother ones are clearly windblown bedforms. The larger, bright ones are shedding boulders, so if they’re old bedforms then they’ve been lithified. How old are they? Billions of years old? Or did they form sometime in the intervening years? (HiRISE ESP_046389_1695, NASA/JPL/Univ. of Arizona)

Fossil dunes

A Piece of Mars: This 1.92×1.08 km (1.19x 0.67 mi) scene shows eroded ridges that are, in fact, lithified dunes. They are so old that you might not recognize them as dunes without more context. This doesn’t happen much on Earth, where inactive dunes are quickly eroded, buried, and/or destroyed by other geologic processes, so enjoy this uniquely martian wonder! (HiRISE ESP_046597_1670, NASA/JPL/Univ. of Arizona)

Dunes not in the global dune database

A Piece of Mars: Ten years ago I participated in a global survey of martian dunes. But we missed a few dune fields, like these beauties. They’re small, low, and in rugged terrain, which made them difficult to spot in the lower resolution data set we used. I keep a list of dune fields we’ll have to add if we get a chance to update the database. This scene is km (0.6×0.34 mi) wide. (HiRISE ESP_043582_1555, NASA/JPL/Univ. of Arizona)

When the martian surface is eroded, pretty things emerge

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

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

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

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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