For billions of years, Mars has been bombarded by numerous asteroids and comets that have left its mark on the red planet's surface. At present, there are 43,000 impact craters recorded that are more than five kilometers, with ancient sites receiving more of a beating than other areas.
In the Martian highlands of the 4-billion-year-old Noachis Terra, the triple craters that are made up of three overlapping basins can be found. Noachis Terra is known as a region that has been heavily impacted by falling meteors.
The triple craters formed a natural Venn diagram formation but it is not as big as the other craters in Noachis Terra, according to ScienceAlert. Some of the region's craters span nearly 87 miles (140 km) across, while the smallest one is 17 miles (28 km).
How Did the Triple Craters Form?
Regarding how the triple craters formed is still a mystery to scientists. One theory suggests that a meteor could have broken down into three parts before hitting the surface of Mars.
Craters such as this are also seen in some parts of the red planet and even here on Earth, although their origins are not the same. For example, astronomers in 2015 noticed a triple crater in Elysium Planitia near Mars' equator. They thought at the time that it could be caused by an asteroid breaking up in the atmosphere or due to a small asteroid that orbits a larger binary pair.
Furthermore, the Mars Reconnaissance Orbiter noticed in 2017 that there was an elongated depression from three merged impact craters which was perhaps caused by three pieces flying in close formation. Others also said that double and triple impact craters are created due to double asteroids that are made up of two or more rocky bodies that orbit each other.
On average, there is only 2% of all asteroids form two or more bodies like this, but that does not mean that it will not bump with a planet and leave a mark.
Another one explanation for the occurrence of triple impact craters is that there were three separate collisions of meteor and Mars which coincidentally fell on almost the same spot as the previous meteors.
A press release from the European Space Agency reads: "at different points in time, three separate impactors could have hit Mars' surface in this location, creating a neat superposition of craters completely by chance."
Tougher Mars Atmosphere Four Billion Years Ago
Scientists believe that if the formation of the triple craters on Mars is not due to three coincidences and that the effect was separated before hitting Mars, then the atmosphere of the red planet must have been too tough four billion years ago, much harder to cross than it is now which is a sign of humidity and warmth.
Also, the triple craters represent the flattened rims and shaggy floors of the crater from the wear and tear in which some of it suggests a glacier-like flow that may have helped soften the earth underneath the melting ice, Sprout Wired reported.
Check out more news and information on Mars in Science Times.
