Is there life on Mars? It's a question that has fascinated scientists, storytellers, and dreamers for generations. With each new mission to the red planet, we get a little closer to the truth.

And now, thanks to high-tech rovers like NASA's Perseverance, we may be on the verge of answering that age-old mystery.

If you're curious about what these machines are really finding up there, let's take a close look at what science is discovering on our planetary neighbor.

Why Mars Is So Interesting

Mars is often called Earth's "sister planet." It's not too far away, and it has seasons, polar ice caps, and even signs of ancient rivers and lakes. Scientists believe that billions of years ago, Mars had liquid water on its surface — and where there's water, there might be life.

Mars also has a day length similar to Earth's and experiences weather, dust storms, and changing temperatures. Although it's cold and dry now, Mars wasn't always like this, which is why researchers think it's a good place to search for signs of past or even present life.

The Role of the Perseverance Rover

NASA's Perseverance rover landed on Mars in February 2021 in a place called Jezero Crater. This area was chosen because it's believed to be the site of an ancient river delta — a perfect location to search for signs of microbial life.

Perseverance is equipped with some of the most advanced instruments ever sent to another planet. It can:

• Analyze rocks and soil for chemical clues

• Drill samples and store them for future return to Earth

• Use high-resolution cameras to search for patterns that might suggest life

So far, Perseverance has found organic molecules, the building blocks of life, in some Martian rocks. This doesn't confirm life existed — but it's an exciting clue.

Looking for Biosignatures

What exactly are scientists hoping to find as evidence of life? They're mainly looking for biosignatures — chemical or structural signs that living organisms once existed.

These might include:

• Patterns of certain minerals formed by bacteria

• Specific molecules like lipids or amino acids

• Changes in carbon isotopes (a marker for biological activity)

In 2023, NASA scientists announced that some rocks collected by Perseverance had unusual ratios of carbon isotopes, which might be explained by microbial activity — though more research is needed.

Can Life Exist on Mars Today?

Mars is currently cold, with an average temperature of about -63°C (-81°F), and its thin atmosphere doesn't provide much protection from radiation. This makes it hard for life as we know it to survive on the surface.

However, underground environments, where there might be trapped water and protection from radiation, could still be promising. Some scientists suggest that microbes might survive in salty underground lakes or briny ice.

In fact, in 2018, researchers using radar from the European Space Agency's Mars Express mission reported signs of liquid water beneath the Martian south pole — although this discovery is still debated.

Returning Samples to Earth

One of the most exciting parts of the Perseverance mission is that it's collecting rock samples to be returned to Earth by a future mission. NASA and the European Space Agency are planning a Mars Sample Return mission for the early 2030s.

Once scientists can study these samples in Earth-based labs, they'll be able to run much more detailed tests than what's possible on a rover. This could be the breakthrough that finally confirms whether Mars ever hosted life.

What the Experts Say

Many scientists believe that if Mars ever supported life, it was likely microbial and lived billions of years ago when the planet had a thicker atmosphere and more water. Astrobiologist Dr. Sarah Stewart Johnson, in her book The Sirens of Mars, writes that finding fossilized microbes — even just one — would be "one of the greatest discoveries in human history."

Dr. Ken Williford, a key scientist on the Perseverance team, has stated:

"We're looking for signs of ancient life in a place that once had water. If life ever took hold on Mars, this is the place we're most likely to find it."

Why It Matters

Understanding whether life ever existed on Mars isn't just about that one planet. It helps us answer a bigger question: Are we alone in the universe? If life formed on Mars — a dry, cold place — then maybe life is more common than we think, even in other solar systems.

It could also teach us about Earth's own past. Early Mars and early Earth had some similarities, so learning about one helps us understand the other.