Mariner 4 was the first successful probe to orbit Mars and provide close-up photographs of its surface, back in 1965. This was the beginning of more attempts at sending out probes and rovers to understand this distant world.

But have these robotic explorers missed something? Did they miss possible signs of life? If they did, do we need to prepare for the invasion of our home? Will this be the end?

Well, no. If there ever was life on Mars, it’s been dead for a long time. However, it is still the goal of the new NASA mission, Mars 2020, to find evidence of this past life, as well as to find levels of oxygen production for future manned missions, according to NASA.

This mission will include a new Mars rover, based on the previous Curiosity rover, in order to lower costs and risk. This rover will be about the size of a small car and will have a drill tool that will allow it to collect cores of Martian rocks and soil. It will store these cores in the hope that a future mission can collect them and bring them back to Earth where much more complex machines can be used to study them.

These cores could potentially contain signs of past microbial life from long ago when the red planet was able to support life.

The mission is planned to launch in August or July of 2020 when Earth and Mars are in good positions relative to each other for landing on Mars.

So what are the chances that Mars used to be the home of life? At this point, no one knows for sure. According to Jennifer Eigenbrode, a biochemist and geologist at NASA Goddard Space Flight Center in Maryland, Mars become a very hostile home to life billions of years ago when the planet lost its magnetic field. “That left Mars with nothing to block the solar wind, which slowly bled off the planet’s atmosphere” and exposed the surface of the planet to large amounts of radiation from the sun. “This complicates the evolution of a biosphere,” said Eigenbrode.

The next big factor for the potential of ancient life on this planet is water. There are strong signs that water has existed on Mars, including “mudstones and sedimentary bands, which form only if there is water present for a long time, on the order of millennia,” according to Scientific American. In fact, according to Eigenbrode, “Curiosity found evidence that water can bubble to the Martian surface and turn to frost. Perhaps that water is bringing organisms to the surface.”

It is definitely possible that life existed on Mars at some point in the past. Even with constant radiation and no atmosphere, life could have survived on this foreign world billions of years ago. Of course, we will not know for sure for many years.