New data suggests that the many meandering canyons on Mars were partly formed by rain.
Although Mars is cold and dry today, channels on its surface look as if running water shaped them, leading researchers to think the planet was warm and wet in the past. But scientists have struggled to determine whether that water fell from the sky as rain or seeped upward from the ground.
To discern the water’s source, Hansjoerg Seybold at the Swiss Federal Institute of Technology (ETH) Zurich and his colleagues analysed the geometry of Martian valley channels. The channels branch off at relatively narrow angles, as do waterways in arid landscapes on Earth, such as the US Southwest. More-humid landscapes with a lot of groundwater — the Amazon rainforest, for example — host river channels that branch at wider angles.
The discovery bolsters the idea that the Martian channels were carved by surface runoff rather than by water percolating from below.
The paper itself is behind a paywall, so it is unclear whether they included in their analysis the consequences of Mars’s lighter gravity. Regardless, this result is intriguing, even if it has a lot of uncertainty.
From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.
Unfortunately, that is exactly where that journey takes him.
The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.
He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.
Available everywhere for $3.99 (before discount) at amazon
, Barnes & Noble
, all ebook vendors, or direct from the ebook publisher, ebookit
And if you buy it from ebookit
you don't support the big tech companies and I get a bigger cut much sooner.