“Somewhere above, beyond, far off, was the sun.”

Chapter 17 of The Martian Chronicles by Ray Bradbury

I think Mars wants us off its turf… we awoke once again to the absurdity of snow in a warm, red desert.

Our EVA to Candor Chasma was effectively cancelled, leaving Quentin and Alice, responsible for the photogrammetry experiment, with somewhat of a sinking feeling. Without the perspective of this EVA, it was a bit harder to get ourselves started, but it was quickly decided that we would get ahead and do our morning tasks for Sol 18 in advance. Corentin and Jérémy therefore started an EchoFinder session while Alice took a cognitive test in the Hab.

As the morning advanced and the temperatures rose, the thin layer of snow quickly melted, allowing us to conduct an emergency EVA to save the LOAC, an instrument prone to damage due to humidity, and change the other instruments’ batteries. In less than 30 minutes we were suited up: Alice, Adrien, and I would be guided by Quentin as HabCom, who could also give us technical advice from the Hab. While we managed to change the batteries, retrieve the data and reset the instruments, the field mill could not be rebooted, and the weather station was soaked: the screen stayed blank, no matter how hard I tried… We took the latter back inside the Hab to be inspected, as well as the LOAC. 

Over lunch, we discussed our childhood reading habits, a conversation well suited to a rainy day. We were glad to have brought the LOAC back in before it started raining and snowing again by mid-afternoon: Alexandre took good care of him, letting him dry out and delicately brushing off any Martian dust that could have messed with the electronics. Restless as ever, I could not help but keep looking out the window to witness what I could not act upon. While few things are as frustrating to me as not being able to act on a problem, Alice is affected by the weather more than most, as she is in charge of both the photogrammetry and geology EVAs, and has to constantly change an already very complex schedule. 

On a more positive note, Quentin has written some code to plot the different environmental data as functions of time, to correlate them with our activities within the station. He agreed to explain the graphs included in today’s batch of photos: 

“This is the evolution of 3 environmental parameters (temperature, humidity and light) as a function of time in the five modules of the MDRS. By linking this information with physiological parameters, researchers can deduce how stressful a particular environment is. 

But this information can also simply reflect the activity of the Crew members during the day! In rectangle 1, we can see the evolution of the temperature in the GreenHab, which is heated during the night. The temperature decreases, until the lower limit is attained, the heater is then switched on, and the temperature increases. And every half hour or so, this cycle is repeated! 

In the rectangle 2, we can see the brightness increasing in the Lower Deck (yellow curve): somebody has switched on the light. But even more interesting: the humidity is increasing as well. Indeed, it’s time for our daily workout in the Lower Deck! 

These are just examples of what can be done. Looking at the graphs, try to think like a researcher and guess what is happening in each module during the day!” 

On this very Earth-like rainy day, I think it’s important to mention our very own “Mission Support” back on Earth. Every day, they work hard so that these very reports may reach their destination. Message from Crew 275 to Crew 293: Thank you for being our link to our home planet, and for occasionally sending in soccer and rugby scores…

“They began to plan people’s lives and libraries; they began to instruct and push about the very people who had come to Mars to get away from being instructed and ruled and pushed about.”

Chapter n°16 of The Martian Chronicles by Ray Bradbury

When we awoke and found that the Martian desert was once again covered in snow, and having heard the winds howl in the middle of the night, our first reflex was to reach for the binoculars, conveniently placed on the main windowsill, from which we could see the atmospheric instruments. We breathed: rocks, tensors, and metal rods hammered into the ground had kept everything upright ! There was no need for an emergency EVA.

This morning, we decided to change it up a bit: instead of our usual workout session prepared by Corentin, we relaxed and stretched to the sound of a yoga session brought by Jérémy. Feeling a little bit too relaxed and sleepy afterwards, we put on some music, did some push-ups and just goofed around the Hab. It’s these sparse moments of unbridled fun and laughs that convince me our crew works: no amount of hard work or accumulated stress can prevent us from having a good time all together. In the past few days, the song “Cheerleader” by OMI started coming back more and more often during our morning activities; I think it might end up being Crew 275’s mission song ! 

In the Upper Deck of the Hab, I watched this morning as crewmembers came and went, to and from different parts of the station, for their cognitive tests, experiments, routine activities, in the Science Dome or Observatory, in pairs or alone. We have definitely settled in a routine, one that we will only realize was extraordinary once we return to Earth !

After eating a delicious focaccia prepared with dill and tomatoes from the GreenHab, Adrien, Quentin, and I went to the Science Dome to prepare our second EVA to Candor Chasma. We had one hour to study the 3D map of the canyon and try to visualize the location of all 10 checkpoints, before we go out on EVA tomorrow. I was surprised to see how differently I worked the problem compared to when I only had the 2D map: because we could “navigate” inside the canyon and see different views of rock formations, Adrien and I started sketching the location of the checkpoints in the order we would find them when exploring the canyon.

By late afternoon, the winds were not too strong and the sky was clear enough to open the dome of the solar observatory, and Alexandre was able to observe our Sun for the first time! The telescope is equipped with a Hydrogen-alpha filter, making it possible to look at the Sun’s chromosphere without damaging the eyes. It also allows to see certain phenomena, such as prominences, sunspots, and flares on the solar surface. 

Back at the Hab, I saw Quentin working on solving some issues with the location tracking system. Half the crew is now “tagged”, the other half still pending…

I am also proud to announce that Crew 275 has the best possible Health and Safety Officer: to help me feel less restless in the evenings, he prepared an entire workout session just for me ! 

“The men on the porch listened. Hearing nothing, they extended their thoughts and their imaginations out and into the surrounding meadows.”

Chapter 15 of The Martian Chronicles by Ray Bradbury

It’s back to normal for us today, if anything about this mission can be considered “normal”! Corentin got us up and running to start the day with stretching and leg exercises, and we enjoyed breakfast as a crew in the Upper Deck before Alice, Quentin and Corentin had to get ready for the first EVA of the week. The photogrammetry experiment continues! Today’s destination was Candor Chasma, a canyon not far from the station and a place the previous ISAE-Supaero crew had mentioned to us as the best destination for an exploration EVA. The sinuous paths and harsh landscape gave the three of them the opportunity to choose difficult checkpoints to find, which we hope will amplify the added value of the 3D map, compared to its 2D equivalent. After choosing 10 checkpoints, the EVA crew had time to explore Candor Chasma and enjoy the beautiful Martian sights. Thankfully for them, the strong winds we experienced last night dwindled in the early morning, and got stronger after they returned to the Hab, allowing them to use the Parrot drone to 3D-map the canyon. As they ventured out further and further away from the station, Adrien serving as HabCom gradually lost communication with them, and could only “extend his thoughts and imagination” to Candor Chasma with the help of a few bits of radio chatter caught here and there.

While the crew was out on EVA, I visited Alexandre in the observatory. Because of the weather conditions in the past two weeks, very little use of the two MDRS telescopes observatories was made. As the sky gets clearer, Alexandre will be able to start his astronomy project. His objective is to characterize little known asteroids to contribute to an American database. By analyzing the light curve of an asteroid (meaning its luminosity as a function of time), you can deduce some of its characteristics, such as its rotation period, its size, etc. Alexandre’s first observations focused on asteroid Eos. Nevertheless, he was frustrated by the unrelenting wind, as the conditions prevented him from opening the dome of the Musk Observatory and observing the Sun. The observations he had programmed last night were also not performed by the robotic observatory… 

In the afternoon, Quentin deployed all the location tracking anchors in the different modules. I toured the station with him as I wore my tag, and he measured the distance between me and the different anchors. Back at the Hab, we checked the data recorded by the trackers, and found that our movements were correlated with it! Quentin is glad to announce that the location tracking system is now fully deployed and operational.

Adrien and Corentin also conducted a large-scale harvest in the GreenHab: dill, spinach and other greens will make our dinner a little more earthly…

“The boys would hike far out into the Martian country. They carried odorous paper bags into which from time to time upon the long walk they would insert their noses to inhale the rich smell of the ham and mayonnaised pickles.”

Chapter n°14 of The Martian Chronicles by Ray Bradbury

With the sun shining this bright and taking advantage of our rest day, we could almost have gone out for a picnic EVA! Today, we took a break from our daily routine to clean the station, sleep in a little, and take it slow to recharge our batteries. We took time to tell jokes and play a guessing game after lunch, before everyone returned to their activities. On a sidenote, Alice and I had been waiting for this moment for a few days: halfway through the mission, we washed our hair! We came back to the Upper Deck delightfully light-headed, and with smiles on our faces.

The atmosphere was more studious and quieter than last week: some played chess, finished a jigsaw puzzle, cooked, or started preparing for week 3 of the mission. Quentin and I worked for most of the day on the mid-rotation video, which we are anxious to share tonight!

It’s hard to believe that we are already halfway through our mission. Having spent so much time preparing and seeing it go by so quickly is a bit nerve-racking. We have all had different ways of experiencing the MDRS for the past two weeks, and it’s been very interesting to discuss our outlooks for the next two!

“And in certain houses you heard the hard clatter of a typewriter, the novelist at work; or the scratch 

of a pen, the poet at work; or no sound at all, the former beachcomber at work.”

Chapter 13 of The Martian Chronicles by Ray Bradbury

… or the clatter of a keyboard, the journalist at work! I thought that today, I might take up the beginning of this report to mention what constitutes a significant amount of my time at MDRS. I love that I get to follow and observe each crewmember in their assigned work and experiments, as well as participate in their research and lead my own. I am lucky enough to be able to balance out scientific work with more “artistic” activities: taking and editing photos of my crewmates, and doing what I love most, writing. 

Today there were many opportunities to take great pictures, as I participated in the first geology EVA of the mission! Alice, our EVA leader, took Adrien, Jérémy, and I to Kissing Camel Ridge, just South of the MDRS. After exploring the area for a short while, Alice gave us instructions to draw the area we explored so that we could make note of where we had collected samples. She showed us how to choose rock samples and test them with the MetMet before collecting them. This instrument allows geologists to test the magnetic susceptibility and conductivity of rocks directly in the field; this way, one can determine the value of potential samples before even beginning to collect them.

It felt great to go a bit further away from the Hab than usual and see different landscapes, and also have new EVA objectives! The latter having been achieved, we also had a lot of fun joking with each other over the radio as we were collecting the samples. Weary but happy about our outing, we brushed off our dusty knees and returned to the Hab to a great meal prepared by Corentin. Quentin tried making bread, not quite up to his expectations…

After lunch, Jérémy started taking some time to speak individually with each of us, to check on how everyone is doing now that we have almost reached mid-rotation. Quentin also started implementing the location tracking system in the Hab to test it out before it is deployed in the entire station. In the end, there will be 10 integrated circuit boards we call “anchors” dispatched everywhere in the station, and each crewmember will also wear one at all times (these we call “tags”). Every 10 seconds, the anchors and tags will “communicate” with each other and the distance between them will be saved to a database. This way, we will be able to know how much time crewmembers spend in different types of environments (bright or dark, noisy or calm, crowded or not, etc.) thanks to the environmental sensors. Of course, this data will be anonymized! 

Coupled with the physiological and cognitive data we have been collecting, the researcher with whom we are working at the Swedish Royal Institute of Technology, will be able to analyze how the architecture and environment of the station has affected our work, our health and our mental state. 

We are all looking forward to an evening full of laughs, and most importantly, a restful night. 

“Mars could do nothing to them, for they were bred to plains and prairies as open as the Martian fields. They came and made things a little less empty, so that others would find courage to follow.”

Chapter 12 of The Martian Chronicles by Ray Bradbury

“HabCom, for the record, I have never seen a smile so wide on Alexandre’s face!” 

I was sorting the first photos of the day sitting at the Hab table, when I overheard the radio communication between Alice, our HabCom, and Quentin, out on EVA to deploy the weather station, MegaAres and LOAC once and for all (fingers crossed!). MegaAres is finally fully functional! Up until now, Mars had not brought us much luck: MegaAres had to be retrieved for repairs, we had to remove the LOAC because of the rain, and the weather station was knocked out by the wind. Today, all instruments are fully deployed and operational! Even the field mill, an instrument designed to measure the electric field around the weather station, which was left uninstalled because of cabling issues, is up and running. Alexandre was ecstatic, and did a little dance around the antenna at the end of the EVA.

After lunch, the food and water resupply ships landed not far from the station, and moving between the different modules of the station was temporarily suspended. Corentin and I, stuck in the Science Dome for a little while, talked about how difficult it is to continue communicating with our loved ones, our lives being for the most part disconnected from Earth. 

As my heart rate was being monitored for 30 very long minutes for an experiment, and as I stood there doing nothing, I realized once again how deformed our perception of time can be. Mid-rotation is just around the corner, time has gone by much too quickly for my taste, and here I am, 5 minutes into my ECG, feeling like I have been standing there for hours…

Upon returning to the Hab, I was so relieved to see cupboards and cabinets full of food! Watching Alice and Jérémy play catch with cereal boxes was a very endearing sight. 

I feel like everyone is feeling a bit weary tonight: Corentin and Jérémy are working on solving a data handling issue, while Alice is feverishly preparing the schedule for the next week, and Quentin is trying to implement a location tracking system, essential to our experiment in partnership with the Swedish Royal Institute of Technology. Nevertheless, we maintain our optimist outlook on the mission and are glad that all atmospheric experiments are finally deployed. Hopefully, Alexandre will have both more time and good weather in the next few weeks to focus on his astronomy project! 

To inaugurate our new, freshly off-the counter freeze-dried food stock, Jérémy is preparing a lasagna feast for the whole crew!

As you probably already know, the shooting stars that you sometimes see on beautiful summer nights are not really "stars”: they are simply dust or small rocks that burn up in our atmosphere and leave a trail of light behind. But what happens when a larger object enters our atmosphere and does not have time to burn up completely before reaching the ground? This is what today’s article is about.

A meteorite is a rock fragment that comes from an asteroid, a planet, a comet or even a satellite (like our Moon). It becomes a "meteorite" when it lands on our planet.

Most meteorites come from the asteroid belt located between Mars and Jupiter. Some also come from the Kuiper belt (beyond Pluto), and sometimes from the Oort cloud located at the border of the Solar System. There are also Martian, lunar and dwarf planets meteorites.

Why are there more meteorites coming from asteroids than planets? How is a meteorite born?

First of all, it is necessary to understand how these rock fragments are formed and find themselves on Earth’s trajectory. Although the Solar System is big and made up mostly of empty space, many large-scale impacts occurred during the last few billion years. This is often referred to as the "cosmic billiards". When an asteroid impacts another object, it may fragment. But do these fragments automatically become meteorites? No, because the gravitational forces of the parent body lock them in orbit or make them crash back down. In order to reach Earth, the fragments must be freed from the gravitational field. To free itself, the fragment must gain a speed higher than the speed of liberation, which is proportional to   (with  being the density of the parent body and R its radius). Therefore, it becomes harder for a rock fragment to free itself when the parent body is larger and denser. For example, the liberation speed of Mars is about 5000 km/s. However, Earth is larger, and its liberation speed is 11 000 km/s. This is why meteorites come mostly from asteroids, much smaller bodies.

Once released, a rock fragment can fly around the universe for millions of years, until one day, it gets close enough to another celestial body to be attracted by its gravitational field and fall to its surface. This rock fragment then becomes a meteorite.

We’ve seen meteorites come mainly from asteroids. Let’s learn more about them! What are the different types of asteroids?

Asteroids can be roughly classified in two categories: deformed asteroids and spherical asteroids. A spherical asteroid is massive enough for the heaviest elements to gather in the center under the effect of gravity. The asteroid is then qualified as differentiated. Such an asteroid has an internal structure similar to a telluric planet (like Earth and Mars). It is composed of a metallic core in its center. Spherical asteroids give rise to three main types of meteorites. First, the differentiated achondrites that come from the equivalent of the Earth's crust. Second, iron meteorites that come from the core of the asteroid. And finally, mixed meteorites that are a combination of both previously mentioned types, i.e silicate and metal. Thanks to these meteorites, we have a good understanding of the internal structure of Earth, telluric planets in general and asteroids.

As for the deformed asteroids, they give birth to meteorites called chondrites. A large majority of the meteorites we receive come from these asteroids (more than 80%). As they have not evolved since the birth of the Solar System, these meteorites can therefore teach us a lot about that period.

How do you recognize a meteorite? And above all, where to find them?

On Earth, a meteorite is characterized by its fusion crust. Indeed, the rock fragment burns when it enters the Earth's atmosphere, and therefore has a blackened crust. Moreover, meteorites are very compact and dense objects. They are differentiated from terrestrial rocks by the presence of metal in their composition. It is however not recommended to use a magnet to recognize them: it degrades their magnetic properties and thus, impacts their scientific value. It is also not recommended to put them in water to measure their density. Indeed, they usually contain iron and are therefore very vulnerable to rust.

Meteorites found on Earth are often discovered in places that have not evolved for thousands or even millions of years, such as hot and icy deserts. For example, many meteorites are found in Antarctica or in the Sahara. Sometimes, they can also be picked up after impact, near their craters.

Historical anecdote: the first man-made iron tools were made with iron meteorites!

What about meteorites from other planets of the solar system?

Scientists have already identified with certainty more than a hundred meteorites from Mars. Regarding the other terrestrial planets (Mercury and Venus), there are no referenced meteorites for the moment. It is very unlikely that we will find a meteorite coming from Venus. Indeed, because of its large size (about the same as Earth's) and its very dense atmosphere, Venus has a very high release speed. On the other hand, it has been proven that it is possible for a meteorite to come from Mercury. Its small size and lack of atmosphere would allow fragments to break free from its gravitational attraction. Nevertheless, no meteorite has yet been classified for sure as Mercurial. Moreover, the position of this planet close to the Sun and its mass (99% of the Solar System’s mass), means that possible fragments from Mercury would most likely fall into the Sun.

Finally, Mars is not spared from impacts from outer space objects either! Some rovers have found meteorites on its surface, such as Opportunity in 2005 with Meridiani Planum, an iron-nickel meteorite located in the region of the same name. This meteorite is the size of a rugby ball!

« “How do you like Mars, Pop?” 

“Fine. Always something new. I made up my mind when I came here last year I wouldn’t expect nothing, nor ask nothing, nor be surprised at nothing.” »

Chapter 11 of The Martian Chronicles by Ray Bradbury

This morning, we woke up expecting only to be surprised… and we were! 

The forecast announced slightly less fierce winds, allowing the third photogrammetry EVA at North Ridge to take place. Beforehand, the exploration team was shown a 3D render of the same area, and given indications on where to find the checkpoints. The experiment was a success! Jérémy and Alexandre found all six checkpoints much faster and more efficiently than the team with the classic 2D map, and had time left on their EVA to explore North Ridge further. They even mentioned that having seen the 3D map, they felt like they had already been to North Ridge before even going on EVA.

lice was HabCom for the first time, and had fun jotting down notes for the EVA crew to read upon their return. 

Next week, the same process will be repeated at a different location. Alice and Quentin are aiming higher: more checkpoints to find, a greater search radius, and more complex terrain. 

The conditions in which we have been conducting the EchoFinder experiment have also improved!  Thanks to Quentin and the researchers from MEDES, we have been able to transfer the software to a more powerful tablet, making it easier to detect the QR cubes and use the Augmented Reality interface. After Quentin and I performed a test run, Adrien and Alexandre were able to run a full ultrasound session which was successful. Meanwhile, I went to battle with my computer to start creating a mid-rotation video using footage from a first-person camera I wore during EVAs and from our Parrot drones. I cannot believe we are nearing mid-rotation… time flies! 

The Hab smelled of cake and caramel all day, doing wonders for the crew’s morale: using up the last of our flour and dough mixes, Corentin and Adrien baked a chocolate chip cake and a brioche!