A sauropod on Mars
February 24, 2021
This is old news, for those who have been following NASA’s Perseverance rover since before it left Earth, and it’s also not my find–my friend, colleague, and sometime co-author Brian Kraatz send me a heads-up about it this morning.
NASA posted the image above a couple of days ago, in a post called “Mastcam-Z looks at its calibration target“. If you zoom in, you can just make out a tiny silhouette of a sauropod on the ring around the MarsDial (what we call a sundial on Mars).
Here’s a much clearer pre-launch image from the Planetary Society (link), which helped design the calibration targets. Starting at about 7:00 and going around clockwise, there’s an image of the inner Solar System, with the Sun, Mercury, Venus, Earth, and Mars, then DNA, bacteria, a fern, a sauropod, humans (same silhouettes as on the Pioneer probes), a retro-style rocket ship, and finally a motto, “Two worlds, one beginning”, which may be a sly nod to the hypothesis that life in the inner Solar System started on Mars and was later seeded to Earth on meteorites–or possibly vice versa.
What’s with all this bling? It’s all about calibrating the cameras on Perseverance. The MarsDial gives the position and angle of the sun, and the colored dots help calibrate the color output of the cameras. There are other calibration targets for other cameras on board Perseverance, as well as some other technological ‘Easter eggs’ from the folks who designed and built the rover–read more about them here (link).
Perseverance is up there to explore “the potential of Mars as a place for life” (source), both past and future. Its four science objectives are:
- Looking for Habitability: Identify past environments capable of supporting microbial life.
- Seeking Biosignatures: Seek signs of possible past microbial life in those habitable environments, particularly in special rocks known to preserve signs of life over time.
- Caching Samples: Collect core rock and “soil” samples and store them on the Martian surface. [For a future sample-return mission.–MJW]
- Preparing for Humans: Test oxygen production from the Martian atmosphere.
Personally, I have my fingers firmly crossed that Perseverance finds something like this sticking out of a Martian rock:
(That one is actually from Utah, not Mars–see this post.) I don’t see any other way that my particular skill set is going to contribute to the exploration of the Solar System, which I’d really like to do. So I’ll wait, and watch Perseverance send back pictures, and wait some more. Sigh.
Anyway, there’s at least one sauropod on Mars, and that will have to do (for now!).
Bonus: if you haven’t watched the video of the rocket skycrane delivering the car-sized Perseverance to the surface of Mars, you need to. And if you have watched it, who cares, watch it again:
Sauropod Vertebra Picture of the Week 
February 24, 2021 at 9:25 pm
Those are not quite the same silhouettes as on the Pioneer probes, though they are very recognizably derived from them. On Pioneer, the woman’s hands are down by her sides, but in this new bleeding-heart liberal do-gooding woke virtue-signalling probe, the woman is waving, just like the man.
February 24, 2021 at 9:39 pm
OR she’s getting ready to smack him for waving at the neighbors when they’re both naked.
February 25, 2021 at 3:13 am
I seriously don’t get why serious scientists seriously think life had to start on Mars and get wafted here. I mean, it’s been many decades since the electric discharge experiments on assumed primordial earth atmospheric components, showed that all the building blocks were starting to assemble in surprisingly short order. I guess this is no different than Descartes’ “noble savage” – which was a wholly fictional idealization of the wholly fictional “golden past”.
February 25, 2021 at 4:37 am
Oh, I don’t think anyone thinks life had to start on Mars, just that there is so much traffic between Earth and Mars that if life ever was on Mars, it probably had a common origin with life on Earth. And it is slightly easier for life hitchhiking on ejected rocks to move down the gravity well, Sun-wards, than to go in the opposite direction. I think it’s a tantalizing possibility.
February 25, 2021 at 6:10 pm
Yeah, it isn’t that life had to start on Mars, just that Mars probably “stabilized” before the Earth and thus could have had life develop first while our planet was still “recovering” from things like formation of the Moon. Given the amount of impacts going on during that time it isn’t too much of a stretch to suggest that if life originated on Mars before there was any on Earth that said Martian life could have been transported to Earth.
February 26, 2021 at 1:24 pm
I admit I am not an expert in either meteorites or extremophiles, but as far as I know, all the Martian meteorites found here on earth seem to have spent a very long time in space – hundreds of millions to a billion years. And that seems like an extremely long time to survive in a radiation filled vacuum with no water. So I’m very skeptical of a common origin for Earth life and Mars life. (Common origin of complex chemicals that could become building blocks for life is another matter).
February 26, 2021 at 5:52 pm
as far as I know, all the Martian meteorites found here on earth seem to have spent a very long time in space – hundreds of millions to a billion years
Nah, some of them were blasted off Mars less than a million years ago, and the table here doesn’t list any that are over 20 million years old.
And that seems like an extremely long time to survive in a radiation filled vacuum with no water.
Yeah, I agree. But SLIMEs seem pretty improbable, too, so I’ve given up on trying to judge this stuff based on my not-relevant macro-zoological training and personal incredulity.
So I’m very skeptical of a common origin for Earth life and Mars life.
With any luck, we’ll know in the next decade or three.
February 26, 2021 at 8:05 pm
thank you for the correction on the ages of Mars meteorites.
Those figures are a lot better, but even 1 million years is still a long time. (EET 79001 is just 0.73 million, but still …)
The point about SLIMEs is a good one, though it only gets one so far because they do have water (though sometimes very little water), which life on a meteorite might not have in usable form, and sediment with nutrients (though, again, not necessarily very much nutrients), and don’t have to guard against high levels of hard radiation.
SLIMEs also are not (yet) known to survive anything quite like atmospheric re-entry.
Either way, I hope something like SLIMEs are eventually found in a meteor.
Seeing ALH 84001 on the list reminds me of those heady days in 1996 when it seemed microscopic fossils of Martian life had been found in it … but nooo. (I do think fossils of some kind are likely to be eventually be found in Mars rocks though. )
February 26, 2021 at 8:47 pm
The Wikipedia article on panspermia (link) has some cool info (with refs, natch) on the ability of microbes to survive ejection- and reentry-like scenarios. Frankly that sounds like just crazy fun science: “Hey, let’s shoot this rock rilly fast and hard and see if the germs make it!”
February 27, 2021 at 9:15 pm
If Terran and Martian life have a common origin, Venus, pre-Terra, and Theia might also be possibilities. I’m not sure if the faint young sun problem rules out a Martian origin, but it would favor a Venusian origin. pre-Terra, and Theia, wouldn’t have any trouble ejecting material to escape velocity, though t;s unlikely anything would survive on the surface.
February 27, 2021 at 9:17 pm
P.S. But that might not leave enough time for life to evolve before the collision.
March 17, 2021 at 6:29 am
Now that we have proof of bacteria and blue-green algae embedded in solid sea-floor rock surviving for fully 100 million years, revived and (the latter) photosynthesizing(!), any skepticism over survival over a mere million years, even in the harsh environment of space, collapses.
I remember, 30+ years ago, Raul Cano’s reports of bacteria extracted from crops of bees embedded in amber for 25M+ and revived were treated with withering derision, despite their being sequenced and shown to be ancestral to those found in modern bees.