Just north of Mars’ equator lies a 45 km (28 mi) wide impact crater known as Jezero Crater. Scientists believe this location may have once held an ancient lake, making it one of the most promising places in the search for past life on the Red Planet. If microbial life ever existed on Mars, this is one of the places it may still be hidden.In February 2021, NASA’s Perseverance rover began exploring this region, searching for signs that could answer one of humanity’s biggest questions: are we alone in the universe?Could Mars once have supported life? Could microscopic organisms still be hidden beneath its surface? And what would it take to finally confirm that life existed beyond Earth?Many scientists believe Mars and Earth may have exchanged material for billions of years. According to some theories, meteor impacts could have blasted rocks containing microbes from Earth into space, with some eventually landing on Mars. If true, this means life could potentially have traveled between planets naturally.Because of this possibility, some researchers suggest that if life ever started on either planet, it may not be entirely independent. Instead, Earth and Mars could have shared biological material across vast stretches of time, like exchanging ingredients across space.But if life exists on Mars today, it would not resemble anything large or complex. Instead, scientists believe it would most likely be microscopic, adapted to survive extreme conditions such as intense radiation, freezing temperatures, and a thin atmosphere.On Earth, there are organisms known as extremophiles that thrive in conditions once thought impossible for life. One of the most famous examples is the tardigrade, also called the water bear. These microscopic creatures can survive extreme heat, freezing cold, crushing pressure, and even exposure to space.Other bacteria on Earth are capable of forming protective spores when conditions become harsh. In this dormant state, they can survive for long periods without water or nutrients, and even withstand high levels of radiation.These Earth based examples suggest that if life ever developed on Mars, it could potentially survive by hiding underground or within protected rock layers. In fact, some scientists studying Earth’s deep subsurface have discovered microbial life kilometers beneath the surface, thriving without sunlight.Mars shares a similar early history with Earth, which is why drilling beneath its surface is considered one of the most promising ways to search for ancient or even existing microbial life. Protected underground environments could preserve biosignatures for billions of years.NASA’s Perseverance rover plays a key role in this search. It uses advanced tools, including a system called SuperCam, which can analyze Martian rocks from a distance using laser technology. These instruments help scientists determine the chemical composition of the surface and identify areas worth closer inspection.When the rover detects promising targets, it can analyze them further for organic molecules or elements associated with life, such as carbon based compounds, nitrogen, or phosphorus. Because only a limited number of samples can be collected, every decision is critical.If all goes according to plan, future missions will return these Martian samples to Earth. Scientists will then examine them in laboratories using far more powerful instruments than any rover could carry.This sample return mission is one of the most ambitious in space exploration history. If successful, it could provide the first direct evidence of ancient or even existing life beyond Earth.The implications would be enormous. Discovering life on Mars would fundamentally change how we understand biology, evolution, and the uniqueness of Earth. It would be one of the most important scientific discoveries in human history.However, even if no life is found, the mission would still reshape science. It would help researchers understand Mars’ geology, climate history, and whether the planet ever had conditions suitable for life.Previous missions, including the Viking landers in 1976, produced conflicting results when searching for signs of life. Some experiments suggested possible biological activity, while others found no supporting evidence. Decades later, scientists still debate what those results truly mean.More recent discoveries, including traces of methane in the Martian atmosphere, have added new questions. On Earth, methane can be produced by biological processes, raising the possibility that microbial life could exist beneath the surface. However, geological processes can also produce methane, meaning the source is still uncertain.It is also possible that Mars never developed life at all, or that any early organisms were wiped out by catastrophic climate changes or asteroid impacts.Another possibility is that Earth microbes accidentally traveled to Mars aboard spacecraft, meaning any detected life could be the result of contamination rather than native Martian biology.As exploration continues, NASA and international partners remain focused on answering one of the most profound questions ever asked. Whether Mars is lifeless, once lived, or still quietly harboring microscopic organisms beneath its surface, each discovery brings us closer to understanding our place in the universe.