If you’ve ever spent a night in a place away from city lights and gazed at the sky, you may have seen at least one shooting star crossing the sky at full speed. These fast glowing objects are actually chunks of space material that fall to the Earth’s surface , burning when they come into contact with the atmosphere at high speed.
Most of the time, these pieces of matter are so small that they vaporize as they enter the atmosphere and what astronomers call shooting stars or meteors (from the Greek meteoron, “phenomenon in the sky”). Occasionally, one of these pieces of material is large enough not to vaporize during its entry into the atmosphere and reach the ground, at which point it becomes a meteorite.
The vast majority of the 61,000 meteorites that have been recorded are pieces of material that did not become part of any planet during the development of the solar system, but a few are especially curious because they come from other larger celestial bodies.
For example, 134 meteorites have been found that come from the Moon : they are pieces of its surface torn off by some impact energetic enough to remove them from its gravitational field. Impacts on the Moon are not uncommon and hundreds are detected each year, appearing as fleeting points of light on our satellite.
As for the meteorites that come from Mars, so far 132 have reached Earth, almost the same ones that come from the Moon. One of the oldest known Martian meteorites contains 10 times more water than the others , which is further proof that our neighbor had water in the past.
The rest of the planets have it more complicated when it comes to sending us pieces of their surface. Although there is a possible meteorite coming from Mercury, it is to be expected that any chunk of rock ejected from Mercury or Venus will end up heading towards the Sun and not towards us , since our star is much closer and has a more intense gravitational field. The rest of the rocky bodies in the solar system are moons that are found circling around the gas giants that, like the sun, are prone to absorb any piece of rock that is propelled from one of their moons.
