Places on Mars to look for Microbes, Lichens,... Salty Seeps, Melt Water Under Clear Polar Ice, Ice Fumaroles, Dune Bioreactors,...: Where early Mars lifeforms could survive to the present day

The present day habitability of Mars is an area of research that has exploded hugely in the last decade, to the extent that it's often hard to keep track of everything that's going on. Here you can read in detail about many new ideas in this rapidly expanding field.

From salty seeps (for the warm seasonal flows) to melted layers of water in clear polar ice (for the flow like features). Or, from ice fumaroles on Mars masking the heat of a volcanic vent, to advancing sand dunes bioreactors churning salts to the surface in equatorial regions, or temporary lakes after asteroid impacts. So many ideas are suggested every year for possible habitats on Mars, it is hard to keep track of them all.

I wrote this article for wikipedia originally - but also with the motivation to try to get a good overview of the field myself as background for my posts on the subject. It is an attempt to survey the entire field, and I have gone to the original sources to try to cover it in depth. It has many links to the original papers if you want to follow it up in even more detail. As a wikipedia draft article, it is released under CC by SA

This content is also available for free as a web page on my science blog (see link on title page). I've made it available as a kindle book to help those who prefer to read it in book format.

(Note while preparing the kindle book I've found that there are a couple of short sections I forgot to write so will be adding those soon, you might want to redownload your ebook after that if you get it right now)