Hundreds of meteorites originating from only 5 craters on Mars hit Earth

Meteorites entering Earth is a known occurrence. While some of them come from deep space, others originatenear our home planet. Scientists have found that Mars has been the origin point of several of those meteors that hit our planet. Severe impact events on the red planet release debris which gets flung into space, with some of them reaching us as well.

At least 10 such meteorite-forming events have happened in the recent past. The debris breaks free of Mars' gravitational pull and enters the orbit around the sun, and some of them eventually fall to Earth.

“Now, we can group these meteorites by their shared history and then their location on the surface prior to coming to Earth,” Chris Herd, a study co-author, professor of earth and atmospheric sciences, and curator of UA’s Meteorite Collection said.

Hundreds of such rocks have been discovered in the last few years. Scientists now claim that around 200 of those meteorites came from five specific impact craters on the Red Planet. Researchers from the University of Alberta have traced their origin to Tharsis and Elysium, the two volcanic regions on our neighbouring planet.

An estimated 48.5 tonnes of meteorite material enters Earth each day, according to NASA. But it is not always possible to study them since they are mere specks of dust by the time they hit the surface.

Meteorites from Mars

In the 1980s, scientists discovered a group of meteorites that likely had volcanic origins with ages of 1.3 billion years.

A celestial body with volcanic activity had to be its origin point, and Mars fit the bill. This was confirmed when NASA's Viking landers compared the composition of Mars' atmosphere with trapped gases found in these rocks.

However, the study noted that it wasn't possible to trace the origins earlier because a technique called spectral matching was being used. The technique is used to identify and compare the composition of materials by analyzing the patterns of light they absorb or emit. However, factors like terrain variability and extensive dust cover inhibit work using this technique.

Herd says that this “major advance” can help revise previous, limited calculations.

"I call that the missing link — to be able to say, for example, the conditions under which this meteorite was ejected were met by an impact event that produced craters between 10 and 30 kilometres across," he said.

The latest finding can help scientists understand more about the planet's geological past.