Alex McColgan

You've likely all seen the news by now.

NASA found a possible sign of life on Mars.

These tiny spots, barely visible to the naked eye, are the biggest space news in over 50 years.

If this really is a sign of life, it would be the most meaningful discovery in the history of humanity.

but we've been burned by false alarms before.

So have we really done it this time?

I'm Alex McColgan and you're watching Astrum.

Join me today as we dig into the details of what Perseverance found, why scientists are excited, and what it will take to prove we're not alone in the universe.

In February of 2021, NASA's Perseverance rover, or Percy to his friends, touched down on an ancient Martian lake bed.

The Jezero crater was once home to a large body of water, with rivers flowing in and out, carving deltas and carrying sediment.

The soil is rich in clay minerals that can only form in the presence of water.

Percy has been sent to hunt for ancient microbial life.

If it's going to find them anywhere, the Jezero crater seems like a good bet.

You see, ancient lakes often contain perchlorate, which can be metabolized by microbes.

Astrobiologists on Earth study microbes like this in extreme environments to understand if life could survive in similar conditions on other planets.

The rover's job is to look for these possible signs of life, identify and store the most interesting samples of Martian rock, and prepare them to be collected by another space mission for an eventual return to Earth.

One day, in July 2024, while exploring the edges of the ancient Neretva Valles river channel, Percy's cameras spotted something unusual.

A rock from the Bright Angel Formation.

two of the rover's instruments – the Planetary Instrument for X-ray Lithochemistry, or PIXEL, and the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals, or SHERLOCK for short – detected sedimentary rocks made of clay and silt.

On Earth, these materials are excellent preservers of microbial life.