[Ruy Dias de Bivar]

A few years back scientists were claiming they had found meteorites from Mars in Antarctica.

[plain talk]

“A few years back scientists were claiming they had found meteorites from Mars in Antarctica.”

Right. They come from a variety of sources including comets, planets and occasionally from another star system. Isotopic and trajectory analysis can help determine where it may have come from.

https://www.astronomy.com/science/ask-astro-how-do-astronomers-know-if-an-object-came-from-another-star/