How We Decided


The day after tomorrow- that is, February 18, 2021- the Perseverance rover will attempt to land on the surface of Mars.  It will enter the planetary atmosphere at an acute angle, giving it as much time as possible to experience drag and slow down from orbital velocities.  Because Mars’ air is so thin, and the rover is so heavy, this will fail- in the best case, Perseverance would still be going almost a thousand miles an hour when it impacts the surface.  To help save itself, the craft will deploy a parachute of advanced design, seventy feet across and able to withstand supersonic velocities.  This, too, will fail.  Even with a parachute, there is simply not enough air between Perseverance and the Martian surface to slow it down all the way.  So this is where the rockets kick in.  Once air resistance slows the rover to a bit less than two hundred miles per hour, the heavy heat shield will be jettisoned, and a system of secondary rockets will fire against the direction of motion until it slows to near-hovering.  In a final flourish, the rover will descend from the rocket-boosted frame on coiled springs, until it touches down in the western part of Jezero crater in the northern hemisphere of Mars.


As it happens, Perseverance’s destination was one of the very last things we decided about it- not until the craft itself was fairly thoroughly engineered and designed.  Formally, the decision was made by the mission directorate.  In practice, they follow the consensus of the scientific community, which in turn hashes things out at a series of open-invitation workshops.  Things began with a call for white papers- an open suggestion box, basically.  In 2015, the first workshop narrowed things down from thirty serious proposals to eight candidates.  In 2017, the second workshop further winnowed the list down to three.  And in October of 2018, after three days of presentation, debate, and discussion, the final workshop selected Jezero Crater from these final three candidates using a simple vote of all attendees, and passed on the recommendation to the mission leads.

I haven’t been in the business for very long, so the final workshop was the only one of these where I actually participated.  It wasn’t a close vote as such, and I didn’t break any ties, and technically we were just making a strongly worded suggestion.  Nonetheless, my vote is one of the reasons why the Rover will be going to Jezero Crater instead of Syrtis Major or Gusev, and I think I’m entitled to feel ownership of this mission choice, just a little bit.

(This is, of course, terrifying.)

Having gone through the experience, there were a few surprises worth noting.  The first was how small some of the numbers are here.  The conference was not very large: only thirty proposals, debated by just a few hundred attendees.  I’ve seen book review contests with more entries, and that are read by a wider audience.  Which is to say, this is a situation that was, and is, extremely responsive to individual effort.  In that small a room, populated by people that are philosophically committed to changing their minds when they see good evidence or a good argument, one person can stand up and change the future in a very real way.

The second surprise was the attendance requirements.  Or rather, the lack thereof.  The project is public, paid for by American taxpayers, to whom I am profoundly grateful.  And one way the process reflected that public-spiritedness is that this is not a walled garden.  A small attendance fee (iirc, $40?), and you’re in.  You get a vote, if you want to use it.  A few non-scientists even took us up on this; there’s one retiree (a former schoolteacher, I think) that’s attended every major conference I’ve been to in the last few years, and sets up a small table in the back with his home mineral collection just for fun.  In practice this open-door policy is limited by the obscurity of the event itself; if you don’t move in research circles, you have to be something of a space exploration superfan to hear about it.  Still, as symbols go, you could do worse.

And now that we’re coming up on the day itself, the same kind of public-facing mindset is making me think about why I was persuaded to vote for Jezero Crater, what it means to explore there, and how I’d justify that choice to those of you that made the ongoing discovery of Mars possible in the first place.

Keep reading


#space #Mars #Perseverance #the power of science #the more you know #apocalypse cw



Not that anyone’s really keeping track, but I do think that this particular crater in the southern ice cap is the most beautiful (recent) impact on Mars.  HiRISE Image ID ESP_057152_0985, -81.485 latitude, 41.358 longitude, impact event in the late summer of 2018.  I keep coming back to it- the beautiful contrast against the ice, the way that the dark sediments of the ejecta blanket in the center almost form wings, the secondary ring of brighter ice all around it where the whoosh of air and dust cleaned the surface, the speckling of secondary impacts throughout.

One of my privileges as a student of Mars is that my object of study is not inhumanly large, or inhumanly small, or really very abstract at all.  The underlying theories can be, sure; geology isn’t stamp collecting.  But fundamentally, Mars is a place.  You can point to it, it’s over there, and sometimes we go to it.  The smaller dark speckles here are a meter or two across, the larger dark zone is maybe a couple football fields.  Roughly the size of a decent-sized mall parking lot, to walk across it.  Uneven going, since the rubble can range from dust to boulders, and especially towards the center you might clamber across using your hands as much as your feet at times.  You’d be cautious, since the exposed surfaces are so fresh- newly fractured rocks will surprise you with unexpected jagged edges, and even in the low gravity, stones are constantly shifting underfoot because nothing’s settled yet.  Ice pokes through here and there as you get near the outer perimeter, and when you look up from your study area it dominates the landscape, rows of small hillocks receding in to the distance.  It’s a crisp mix of water and carbon dioxide, rather pitted, with mottled patterns of red-black dust tracing across the surface.  Where it’s clean, it’s more of a matte white than you’re used to from snow on Earth, just enough to throw you a bit.  Especially as it picks up color tones from the alien sky above you: blue at the top of the sky’s arch near the sun, but phasing through soft purples to a dull red at the horizon.  The breeze is brisk, but gossamer; in the thin atmosphere, it can barely move the hairs on your arm, and the familiar sound of wind whistling over the rocks seems to come from far away.

Not really going anywhere with this post.  I just think about it sometimes, is all.


#space #Mars



Mars over Toronto. It won’t be this close to Earth again until 2035. (great photo by friend Andrew Yee!) (at Sunnyside, Toronto)


#Mars #juxtaposition #our home and cherished land #this picture is a lot more emotional in its temporal context huh #Toronto looks so beautiful and so ordinary from this distance #you can’t see the pain or fear #the impotent anger at reckless neighbours #”two point two percent” whispers an all-too-fresh memory #(a memory of reading a news release from Public Health Ontario) #(they’re taking blood draws that were done for other reasons and additionally testing them for COVID-19 antibodies) #(that’s the figure for Toronto) #((it’s about one percent averaged over the province)) #I was just talking about Mars being a safe distance #tag rambles #covid19 #illness tw

The Opportunity to Rove on Mars! 🔴


Today, we’re expressing gratitude for the opportunity to rove on Mars (#ThanksOppy) as we mark the completion of a successful mission that exceeded our expectations.  

Our Opportunity Rover’s last communication with Earth was received on June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover’s location on the western rim of Perseverance Valley, eventually blocking out so much sunlight that the rover could no longer charge its batteries. Although the skies over Perseverance cleared, the rover did not respond to a final communication attempt on Feb. 12, 2019.

As the rover’s mission comes to an end, here are a few things to know about its opportunity to explore the Red Planet.

90 days turned into 15 years!

Opportunity launched on July 7, 2003 and landed on Mars on Jan. 24, 2004 for a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days. While we did not expect the golf-cart-sized rover to survive through a Martian winter, Opportunity defied all odds as a 90-day mission turned into 15 years!


The Opportunity caught its own silhouette in this late-afternoon image taken in March 2014 by the rover’s rear hazard avoidance camera. This camera is mounted low on the rover and has a wide-angle lens.

Opportunity Set  Out-Of-This-World Records

Opportunity’s achievements, including confirmation water once flowed on Mars. Opportunity was, by far, the longest-lasting lander on Mars. Besides endurance, the six-wheeled rover set a roaming record of 28 miles.


This chart illustrates comparisons among the distances driven by various wheeled vehicles on the surface of Earth’s moon and Mars. Opportunity holds the off-Earth roving distance record after accruing 28.06 miles (45.16 kilometers) of driving on Mars.

It’s Just Like Having a Geologist on Mars

Opportunity was created to be the mechanical equivalent of a geologist walking from place to place on the Red Planet. Its mast-mounted cameras are 5 feet high and provided 360-degree two-eyed, human-like views of the terrain. The robotic arm moved like a human arm with an elbow and wrist, and can place instruments directly up against rock and soil targets of interest. The mechanical “hand” of the arm holds a microscopic camera that served the same purpose as a geologist’s handheld magnifying lens.


There’s Lots to See on Mars

After an airbag-protected landing craft settled onto the Red Planet’s surface and opened, Opportunity rolled out to take panoramic images. These images gave scientists the information they need to select promising geological targets that tell part of the story of water in Mars’ past. Since landing in 2004, Opportunity has captured more than 200,000 images. Take a look in this photo gallery.


From its perch high on a ridge, the Opportunity rover recorded this image on March 31, 2016 of a Martian dust devil twisting through the valley below. The view looks back at the rover’s tracks leading up the north-facing slope of “Knudsen Ridge,” which forms part of the southern edge of “Marathon Valley

There Was Once Water on Mars?!

Among the mission’s scientific goals was to search for and characterize a wide range of rocks and soils for clues to past water activity on Mars. In its time on the Red Planet, Opportunity discovered small spheres of the mineral hematite, which typically forms in water. In addition to these spheres that a scientist nicknamed “blueberries,” the rover also found signs of liquid water flowing across the surface in the past: brightly colored veins of the mineral gypsum in rocks, for instance, which indicated water flowing through underground fractures.


The small spheres on the Martian surface in this close-up image are near Fram Crater, visited by the Opportunity rover in April 2004.

For more about Opportunity’s adventures and discoveries, see:

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#Mars #Opportunity #space #the power of science #death tw?






dude seeing these Mega high quality images of the surface of mars that we now have has me fucked up. Like. Mars is a place. mars is a real actual place where one could hypothetically stand. It is a physical place in the universe. ITS JUST OUT THERE LOOKING LIKE UH IDK A REGULAR OLD DESERT WITH LOTS OF ROCKS BUT ITS A WHOLE OTHER PLANET? 


i hate to be rude and intrude on this post but we have decent pictures of the surface Venus too! 

#venus has a low render distance

See also below Saturn’s moon, Titan. Mars has a blue horizon at sunset so it looks even more Earth-like in this image:


Also: Comet 67P/Churyumov–Gerasimenko

Here’s a bit more on the Titan one.


#space #the power of science #the more you know #Venus #Mars #Titan #Rosetta #flashing gif

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Send me to Mars with party supplies before next august 5th

No guys you don’t understand.

The soil testing equipment on Curiosity makes a buzzing noise and the pitch of the noise changes depending on what part of an experiment Curiosity is performing, this is the way Curiosity sings to itself.

So some of the finest minds currently alive decided to take incredibly expensive important scientific equipment and mess with it until they worked out how to move in just the right way to sing Happy Birthday, then someone made a cake on Curiosity’s birthday and took it into Mission control so that a room full of brilliant scientists and engineers could throw a birthday party for a non-autonomous robot 225 million kilometres away and listen to it sing the first ever song sung on Mars*, which was Happy Birthday.

This isn’t a sad story, this a happy story about the ridiculousness of humans and the way we love things. We built a little robot and called it Curiosity and flung it into the star to go and explore places we can’t get to because it’s name is in our nature and then just because we could, we taught it how to sing.

That’s not sad, that’s awesome.

*this is different from the first song ever played on mars (Reach For The Stars by Will.I.Am) which happened the year before, singing is different from playing

Human Beings: These Are My People

(You can hear what the song would have sounded like here.)

@agapi42​, thank you for reminding me it’s Curiosity’s birthday today! Here are some more details.

The link I included last time has since rotted, so here’s a replacement.


#birthday #Curiosity #Mars #the power of science #music #space