NASA rover discovers liquid water 'ripples' carved into Mars rock

In $FAVORITE_COUNTRY, they dig and find even older: "we're the best!"

In $OTHER_COUNTRY the dig and find nothing: "we must have been the first to invent Wi-Fi!"

:-P

So I imagine, if there was evidence for life on Mars, before the habitability went sideways, then it would likely be many feet deeper than we ever dug.

I'm not holding my breathe, because the likelihood is pretty small, as all this happened 3.6 billion years ago, but if we did find undisputable evidence of civilization, it would be game changing.

I simply hope it isn't Prothean ruins and a map to the nearest Mass Relay, cause what comes next is a bad time.

That is equivalent to driving from SF to San Jose and recording what you see out the window if your car.

Good question. I would like to spend $10B searching, which amounts to a one time cost of about $30/American.

Historically, investments in NASA have a very good return, since building cutting edge aerospace tends to directly percolate into the economy. Not to mention the technological advancement it will likely spur.

> While life “follows the water” in the desert, it is scattered and its distribution follows the subtle reaches of the fog or that of invisible aquifers, which are dictated by complex geographical and topographical parameters. It can be abundant in a localized patch (millimeters to a few hundreds of meters in size) and then disappear for many kilometers. It can be present on one wall of a small gully and absent from the opposite wall only ten centimeters away. Keys to finding microscopic life are critical at all scales. They are found at the megascale (regional geology, morphology, topography, and climatology); at the mesoscale (a slope, a rock, a type of soil, a specific size of sediment); and at the microscale (a crack in a rock, pore and joint spaces, grain translucence). The success of finding life while exploring the desert on foot depends on integrating all of this information, a task which robotic exploration needs to achieve as well.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/200...

The same happens with the astronauts coming back to Earth, who survive despite the external shield being vaporized by the heat. If a body has low thermal conductivity and high thermal capacity, the inner part will maintain a low enough temperature, even when the outer part is above boiling temperature.

On Earth, one can find bacteria in some rocks that are not completely compact, but which have pores or crevices, through which the water and gases needed by bacteria can pass.

Such events would be unlikely, but not impossible.

In the early Solar System, when big impacts were very frequent, there must have been many cases of rocks traveling between close planets, in all directions.

After the planets had reached their current structure, meteorites coming from either Mars or Moon to Earth have remained frequent, due to the lack of a thick atmosphere on Mars and Moon, combined with their weaker gravity, but meteorites going from Earth to any of them have become extremely unlikely, because most bodies colliding with the Earth do not reach its surface, and for the few that reach the surface the probability that an ejected rock could exit Earth's atmosphere is even lower.