How 2 billion craters on Mars were created by 1 asteroid

Craters on Mars: Black and white image of large crater with flows of debris surrounding it.
This is the Corinto crater in Elysium Planitia on Mars. A new study using data from Mars Reconnaissance Orbiter (MRO) shows the single asteroid impact that created Corinto also created about 2 billion much smaller secondary craters on Mars, up to 1,200 miles (2,000 km) away. Image via NASA/ JPL/ M. Golombek et al.
  • About 2 million years ago, an asteroid hit Mars and created Corinto crater. A massive amount of smaller debris from the impact formed nearly 2 billion other, smaller craters on Mars.
  • The debris created new, small craters as far as 1,200 miles (2,000 km) from the original asteroid impact site.
  • Scientists determined the number of craters using imaging data from Mars Reconnaissance Orbiter.

1 asteroid = 2 billion craters

Some 2.3 million years ago – relatively recent in geologic time – a space rock careened toward Mars. It smashed into the Red Planet, hurling massive amounts of ejecta out of its newly formed crater. With no plate tectonics and little weathering, Mars still bears the scars of that impact today. Researchers counted the secondary craters formed from flying Martian rocks and dirt. Did they find hundreds? Thousands? Nope, the researchers found nearly two billion smaller craters! These craters are a minimum of 32 feet (10 meters) in size, lying up to 1,200 miles (2,000 km) from the main crater. The researchers presented their findings at the Lunar and Planetary Science Conference (LPSC 2024) in The Woodlands, Texas, in March.

You can read the new paper on the Universities Space Research Association (USRA) website.

Help spread the wonders of astronomy! Please donate now to and ensure that people around the world can learn about the night sky and our universe.

A large impact crater and many smaller ones

The international team of researchers focused on a crater called Corinto, just north of the Martian equator in Elysium Planitia. Corinto is fairly large, about nine miles (14 km) across and 0.6 miles (one km) deep. So, when its parent asteroid hit Mars, it produced a lot of debris called ejecta. Secondary impacts created smaller craters both inside and outside the main crater.

The researchers used imaging data from the HiRISE and Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) to study Corinto. The paper stated:

Orbital thermal and visible imaging datasets are used to describe the crater, ejecta blanket, four facies of rays and secondary craters, and to estimate the age of the impact and the total number of secondary craters.

The researchers examined four different kinds of craters around Corinto. Those five groups are what’s known as facies. Each group is distinct in appearance, largely due to how far away they are from Corinto crater. The craters closest to Corinto are semi-circular and have no ejecta of their own. They also have distinct rims. But some of the craters farther away are long and narrow looking.

Studies of the main crater also showed the ground was likely saturated with water ice. As a result, the superheated ice degassed during the impact.

Brownish terrain with many small craters. One crater has colorful streaks around it.
View larger. | This image from the HiRISE camera on Mars Reconnaissance Orbiter (MRO), taken January 13, 2018, shows a field of small craters just outside of Corinto crater (out of view). They are just some of the 2 billion small craters created by secondary impacts. The crater with the colorful ejecta is actually a much more recent one. Image via NASA/ JPL-Caltech/ UArizona/ HiRISE.

Craters on Mars

Scientists calculated the angle of impact was about 30-45 degrees, with the asteroid coming from the north. Coming in from that northerly angle, most of the debris fell back to the surface to the south of the crater.

Consider the great distance from the main impact to the furthest craters, an incredible 1,200 miles (2,000 km) apart. It would be like an asteroid hitting Los Angeles and the debris reaching halfway across the United States to Dallas. What might it have been like to witness that impact and massive debris shower?

Bottom line: An asteroid created a large Martian crater called Corinto, about 2 million years ago. Debris from the impact also created 2 billion smaller craters on Mars.

Source: Corinto: A Young, Extensively Rayed Crater that Produced a Billion Secondaries on Mars

Via Universe Today

Read more: Giant volcano on Mars hiding in plain sight

Read more: Ancient volcanoes on Mars were diverse

March 28, 2024

Like what you read?
Subscribe and receive daily news delivered to your inbox.

Your email address will only be used for EarthSky content. Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

More from 

Paul Scott Anderson

View All