We knew that the liquid water being buried deep in the subsurface was one possible solution to the question of where Mars' ancient liquid surface water went,
There were thoughts that some of the water escaped when Mars lost its atmosphere,
If we do not take action to reduce and eventually eliminate our carbon emissions, they will overwhelm human civilisation as we know it, long before Mars is ready to be colonised by large numbers of people,
So we just need water in some form for human existence as well as making rocket fuel,
In 10-15 years, it might not look like science fiction any more,
Elon Musk is making a Starship which can carry 200 people to Mars in six months. It’s all coming together,
Most likely, those salt deposits formed from shallow ponds of water or brine that evaporated in the sun,
A new instrument on the rover will be the first drill to a depth of up to 6.5 feet (2 meters) deep below the surface to collect ice samples that have been protected from surface radiation and extreme temperatures,
People use a similar method to produce salt for human consumption in saltwater pools on Earth,
It's sequestered 10-20km deep in the crust,
Without liquid water, you don't have life,
Drilling a hole 10km deep on Mars — even for [Elon] Musk — would be difficult,
These are actually the same techniques we use to prospect for water on Earth, or to look for oil and gas,
On Earth, groundwater infiltrated from the surface" to deep underground
I’m inspired and I hope the public is also inspired,
On Earth, we find microbial life deep underground where rocks are saturated with water and there is an energy source,
At these depths, the crust is warm enough for water to exist as a liquid. At more shallow depths, the water would be frozen as ice,
Early Mars had liquid water on its surface in rivers, lakes and possibly oceans. The crust on Mars could also have been full of water from very early in its history, too,
InSight was able to measure the speed of seismic waves and how they change with depth. The speed of seismic waves depends on what the rock is made of, where it has cracks and what fills the cracks,
A mid-crust whose rocks are cracked and filled with liquid water best explains both seismic and gravity data,