No, not the super awesome episode of Doctor Who. And forgive me if I keep this short and only semi-coherent. I’ve spent most of my day staring at thin sections of fossilized sea varmint poop (you heard me right) so… yeah. It’s the glamor. That’s why I chose this educational path.
However, Mars is much more glamorous than peloids. Fortuitously enough, the geological colloquium today featured Bryan Hynek, who researches Mars. He did an interesting talk about Martian river valleys, and also the existence of an early ocean on Mars.
Mostly what struck me about the river valley portion was just how much higher resolution imaging has done for the field. In one example, he showed an area that had an extremely small drainage density when calculated from pictures taken by the Viking (if I remember correctly) mission. With the newer, higher resolution data a lot more tributaries are apparent and the drainage density in that area climbed up to something you’d expect to find in Utah. Which isn’t to say Mars was a watery paradise back in the Noachian, but it had actively flowing water. Looking at the river valley distribution and age, it was mostly concentrated in the early history of the planet, but it’s still interesting to think of Mars as a significantly wet planet.
This lead in to looking at the possibility of a Martian ocean, which isn’t really a new idea. Using climate models, it’s apparently not really possible to create the sort of drainage networks that have been found without an ocean. This is actually not an idea I’d been exposed to before, probably because I don’t read nearly enough about planetary geology. Bryan also looked at river deltas (some of the pictures had the classic bird’s foot shape like the Mississippi delta) that emptied into the probable site of the ocean and used that to estimate the sea level and thus the shoreline. He had a striking picture of Mars with elevations up to the proposed sea level filled in with blue. There’s something jarring about seeing a third of the red planet hidden under and ocean.
There are still a lot of questions to be answered (like the big issue of constructing an atmosphere for the Noachian epoch that would have made this possible and sourcing all of the gases), and doesn’t really do much for the question of if there’s water on Mars today – but it’s a lot of fun to think about if nothing else. And cool. Let’s not forget cool. And it made me remember all sorts of terminology from geomorphology that I’d almost managed to forget.
Oh yes, and evidence of moraines left by retreating glaciers on the volcanoes. Pitterpat goes my heart.
I’ll add it to my list of things to do as soon as time travel is invented, right after (3) Pet a [herbivorous] dinosaur – (4) Go sailing on Mars. Do not forget respirator.
