New census of inverted channels on Mars strongly suggests the planet once had more water
Click for original image.
A new review of inverted channels on Mars now strongly suggests that the red planet was once far wetter than presently seen, with the channels implying the existence of liquid rivers.
The discovery of more than 15,000 kilometres of ancient riverbeds on Mars suggests that the Red Planet may once have been much wetter than previously thought. Researchers looked at fluvial sinuous ridges, also known as inverted channels, across Noachis Terra – a region in Mars’ southern highlands. These are believed to have formed when sediment deposited by rivers hardened and was later exposed as the surrounding material eroded.
Similar ridges have been found across a range of terrains on Mars. Their presence suggests that flowing water was once widespread in this region of Mars, with precipitation being the most likely source of this water.
The image to the right is a good example of an inverted channel, a previous cool image posted in April 2025. It is located not in Noachis Terra but in the northern lowland plains.
The researchers argue that these channels suggest that about 3.7 billion years ago there were flowing liquid rivers on Mars, fed by precipitation. This conclusion however still does not explain how this could happen on a planet that is too cold with too thin an atmosphere for liquid water to exist. Every model so far proposed to make Mars warmer with a thicker atmosphere in the distant past remains questionable with many holes.
Could the inverted channels have been created by glacial activity, ice instead of liquid water? At present we don’t know enough about the Mars environment and the physics of such things in the planet’s one-third gravity to answer that question. It is however a question that scientists I think should be asking, based on the extensive evidence of glacial activity in the Martian mid-latitudes.
The big takeaway from this study however is that it adds weight to the overall trend seen in the data, that over time the total amount of water on the planet has declined. We can see this in glaciers, for example, with later glacial flows always falling short of previous flows. This research shows that even in the dry tropics there was once ample water, even if we don’t yet know what form it took.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for original image.
A new review of inverted channels on Mars now strongly suggests that the red planet was once far wetter than presently seen, with the channels implying the existence of liquid rivers.
The discovery of more than 15,000 kilometres of ancient riverbeds on Mars suggests that the Red Planet may once have been much wetter than previously thought. Researchers looked at fluvial sinuous ridges, also known as inverted channels, across Noachis Terra – a region in Mars’ southern highlands. These are believed to have formed when sediment deposited by rivers hardened and was later exposed as the surrounding material eroded.
Similar ridges have been found across a range of terrains on Mars. Their presence suggests that flowing water was once widespread in this region of Mars, with precipitation being the most likely source of this water.
The image to the right is a good example of an inverted channel, a previous cool image posted in April 2025. It is located not in Noachis Terra but in the northern lowland plains.
The researchers argue that these channels suggest that about 3.7 billion years ago there were flowing liquid rivers on Mars, fed by precipitation. This conclusion however still does not explain how this could happen on a planet that is too cold with too thin an atmosphere for liquid water to exist. Every model so far proposed to make Mars warmer with a thicker atmosphere in the distant past remains questionable with many holes.
Could the inverted channels have been created by glacial activity, ice instead of liquid water? At present we don’t know enough about the Mars environment and the physics of such things in the planet’s one-third gravity to answer that question. It is however a question that scientists I think should be asking, based on the extensive evidence of glacial activity in the Martian mid-latitudes.
The big takeaway from this study however is that it adds weight to the overall trend seen in the data, that over time the total amount of water on the planet has declined. We can see this in glaciers, for example, with later glacial flows always falling short of previous flows. This research shows that even in the dry tropics there was once ample water, even if we don’t yet know what form it took.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News