Skip to main content

How researchers use impact craters on Mars to date geological events

While rovers visiting the surface of Mars are invaluable research tools for understanding surface chemistry and other questions, observing Mars from orbit can help us understand the planet’s history — as recent images of a martian impact crater show.

The Mars Express orbiter uses its High Resolution Stereo Camera (HRSC) instrument to take photographs of the Martian surface, including geographical features and locations of water ice. Recently, ESA has shared images created from HRSC data of deep gouges on the surface of the Tantalus Fossae region. These troughs are part of a fault system that stretches nearly 1,500 miles across and are located around the edges of a low-lying volcano called Alba Mons.

This image from ESA’s Mars Express shows part of a large fault system on Mars known as Tantalus Fossae. This image comprises data gathered by Mars Express’ High Resolution Stereo Camera (HRSC) on 19 July 2021. It was created using data from the nadir channel, the field of view aligned perpendicular to the surface of Mars, and the colour channels of the HRSC. It is a ‘true colour’ image, reflecting what would be seen by the human eye if looking at this region of Mars.
This image from ESA’s Mars Express shows part of a large fault system on Mars known as Tantalus Fossae. This image comprises data gathered by Mars Express’ High Resolution Stereo Camera (HRSC) on 19 July 2021. ESA/DLR/FU Berlin

“The fossae were created as the summit of Alba Mons rose in elevation, causing the surrounding surface to become warped, extended, and broken,” ESA explains. “The Tantalus Fossae faults are a great example of a surface feature known as grabens; each trench formed as two parallel faults opened up, causing the rock between to drop down into the resulting void.”

This oblique perspective view of Tantalus Fossae on Mars was generated from the digital terrain model and the nadir and colour channels of the High Resolution Stereo Camera on ESA’s Mars Express.
This oblique perspective view of Tantalus Fossae on Mars was generated from the digital terrain model and the nadir and color channels of the High Resolution Stereo Camera on ESA’s Mars Express. ESA/DLR/FU Berlin

Another image shows the same region but from a different angle, as generated from digital information collected by the HRSC instrument and others. By bringing together information about elevation and surface features from different instruments, digital terrain models can be generated that show what the terrain looks like in three dimensions.

The large crater shown in the images can be helpful in dating the grabens features. The crater would have been caused when a chunk of rock or ice came streaming through the thin atmosphere and hit the planet, throwing up debris and creating a shock wave that forms a circular shape in the surface rock. The force of this impact would obliterate any surface features which existed there previously.

As the grabens can be seen running across the impact crater, they must have been formed after the impact occurred. This is one way that geologists build up a picture of the history of distant bodies like Mars or the moon, by looking at the age of certain geological events relative to particular impact craters. This impact crater is an old one, and it was already present on the surface when the Alba Mons volcano started pushing up to the surface and forming the faults of Tantalus Fossae.

If you look carefully at the top image, you can see another impact crater, much smaller and located at the bottom left of the main crater, which cuts across the fault lines. That suggests it is much younger and was created by an impact that occurred after the fault system formed.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
See a postcard from Mars taken by the Curiosity rover
NASA’s Curiosity Mars rover used its black-and-white navigation cameras to capture panoramas of “Marker Band Valley” at two times of day on April 8. Color was added to a combination of both panoramas for an artistic interpretation of the scene.

Today, you can enjoy a stunning new view of Mars, thanks to a postcard from the Gale Crater taken by the Curiosity rover. The image combines two different views of the same area and is colorized to show off the undulating martian landscape in a region called the Marker Band Valley.

The image, shared by NASA's Jet Propulsion Laboratory (JPL), shows the back of the rover and views of the tire tracks it has left across the martian surface as it has driven. The view on the left side of the image was taken in the morning of April 8, at 9:20 a.m. local Mars time, while the image on the right side was taken on the same day but in the evening, at 3:40 p.m. local Mars time. The two images have been blended together to show how the landscape looks different throughout the day.

Read more
NASA lost contact with Mars Ingenuity helicopter for a week — but it’s OK now
NASA's Ingenuity helicopter.

NASA has announced that it recently lost contact with the Ingenuity helicopter on Mars for a week. Communications with the helicopter have now been restored, and it will continue exploring Mars's Jezero crater along with the Perseverance rover.

The Ingenuity helicopter has outlasted all expectations, originally designed to make just five flights but completing an incredible 51st flight in April. However, this extended lifespan means that the helicopter has run into problems, particularly when the Martian winter set in and it was difficult for its solar panels to generate enough heat to keep its electronics warm. This means that the helicopter must deal with occasional brownouts of power during the nighttime, which can affect the time at which the helicopter wakes up each morning.

Read more
NASA’s June skywatching tips include Mars in the Beehive
how to photograph perseid meteor shower night sky with

What's Up: June 2023 Skywatching Tips from NASA

NASA is back again with its monthly roundup of what to look out for in the sky over the coming weeks.

Read more