The fact that Mars was a planet eerily similar to Earth is no surprise any longer.
But just how similar was it to our homeworld? Did the red planet once have oceans, lakes, and rivers? Did it have vegetation? And is it possible that life once existed in the now, barren and dry alien world?
Imagine asking these questions some 30 years ago. Astronomers would have immediately said that the red planet likely never had flowing water on its surface.
That’s because, at that time, we did not have data we have today.
We didn’t have spacecraft with eagle-eyed cameras orbiting the planet, snapping images of its surface.
We also did not have robots exploring the surface looking for traces of past life.
Now we know that Mars had liquid water on its surface. It had oceans, it had rivers and lakes. It also had an atmosphere that protected the planet from hazardous space weather.
Now, all of that is gone.
But evidence of the red planet’s ‘bluer’ past can be found if we look carefully.
New, recently-published images taken by the European Space Agency’s Mars Express Satellite reveal traces of past water flow on Mars.
The new satellite images show a desiccated system of trenches and valleys — signs of ancient water flow across the Martian surface, according to the ESA.
“We see Mars as a cold, dry world, but plenty of evidence suggests that this was not always the case,” the ESA explained in a statement.
Dig out your 3D red-green or red-blue glasses for this spectacular image of dried-up river beds on #Mars! This anaglyph was derived from data obtained by the High Resolution Stereo Camera (HRSC) on the @esascience Mars Express spacecraft.
View full image: https://t.co/hMUDOYUBjz pic.twitter.com/ZbKeVtGa1F
— ESA (@esa) February 23, 2019
“Research in past years instead increasingly indicates that the planet once had a thicker, denser atmosphere that was able to lock in far greater amounts of warmth, and therefore facilitate and support the flow of liquid water on the surface below.”
The traces of past water flow on the red planet were found by the Mars Express satellite as it was flying just above the southern highlands of Mars, located east of a massive and well-known impact crater called Huygens and just north of Hellas, the largest impact basin on the red planet’s surface.
Scientists say that the southern highlands on Mars are some of the oldest and heavily crated parts of Mars, and are between 3.5 to 4 billion years old.
And it is precisely there, an area filled with scars of ancient Mars where the ESA say ancient water flows have been observed.
In fact, as explained by scientists, the topography tells us that water flowed downhill from the north to the south, carving massive valleys up to 1.2 miles across and more than 600 feet deep. The valleys, which formed billions of years ago have since gone through significant and heavy erosion.