Here's How Scientists Determined That Mysterious Meteorites Came From Mars
The answer lies in cosmic gas.
Have you ever wondered what it takes to understand whether a rock that you find on Earth belongs to another planet or not? Our planet carries the occasional visitors from interstellar space as well as our closest neighbors. As of September 2020, 277 meteorites have been categorized as Martian, accounting for fewer than half of the 72,000 meteorites classified. These were formed millions of years ago when asteroids and other space rocks smashed with the surface of Mars, thus ejecting fragments of its crust into orbit. When gravity is just right and draws them in, these drifting rock fragments find themselves drifting into the Earth's atmosphere.
In fact, the first Martian meteorite was discovered in 1983, with scientists linking its materials back to an impact 700,000 years ago on Mars. But how was this possible? We needed materials returned from the Moon to identify lunar meteorites, but we couldn't do that with the Martian meteorites. The answer lays hidden in the gasses trapped within rocks. If you're curious to know how the scientists were able to pull it off, make sure you watch the video by Scott Manley above, and as always, enjoy!