Will Ares finally answer “Are we alone?”

We recently looked at how and why the planet Venus could answer the long-standing question: Are we alone? Despite its harsh surface environment, its atmosphere could be hospitable to life as we know it. Here, we will examine the planet Mars, also known as the Red Planet and the fourth planet in our solar system, which has fascinated sky watchers from ancient times to the present day.

In terms of space exploration, no planetary body has been visited more times than Mars, with NASA’s Mariner 4 becoming the first spacecraft to image the Red Planet in 1965. Today, there are 3 rovers and 1 lander exploring Mars , along with over a dozen orbiters teach us something new about this mysterious world every day. But what makes Mars so fascinating to study?

“Mars fascinates me in many ways,” said Dr. Antonio Paris, who is a principal investigator at the Planetary Science Center and its author Mars: Your Personal 3D Journey to the Red Planet. “From science fiction to science, the Red Planet can serve as a lifelong research interest in unraveling the mysteries of the Solar System, such as how did life begin on Earth and will our planet suffer the same fate as Mars?”

Today, Mars is both a cold and dry world, with average surface temperatures ranging from -140 to 21 degrees Celsius (-220 degrees to 70 degrees Fahrenheit) and not a single drop of liquid water on the surface. This lack of water is explained by the lack of atmospheric pressure, which is a paltry one percent of Earth’s pressure. Like Venus, this does not bode well for life as we know it. So what makes Mars so interesting for astrobiology and finding life beyond Earth?

“Mars was much more like Earth,” said Dr. Mackenzie Day, who is an Assistant Professor in the Department of Earth, Planetary and Space Sciences at UCLA. “It had liquid water flowing all over the surface that carved river valleys and filled craters to form lakes. Lakes in particular are great places to find life on Earth, so Mars is an interesting astrobiological target because it had so many lakes. The Mars 2020 rover, Perseverance, is currently exploring a dry paleolake with a delta deposit in its interior. Deltas on Earth naturally organize sand, mud, and gravel by size, and we know that the best place to find signs of life is in the smallest grains. Taking advantage of what we know about deltas on Earth (such as the Nile River Delta or the Mississippi River Delta) will improve the rover’s chances of making particularly exciting discoveries.”

Evidence suggests that billions of years ago, Mars was a much hotter and wetter place, and current Mars missions are trying to figure out whether life once existed on the surface or even just beneath it. While we’ve learned a lot of science about the Red Planet in just the past few decades, humans can’t study Mars directly because we don’t have samples back on Earth. But that could all change with NASA’s Mars Sample Return mission set to launch in the late 2020s. Meanwhile, NASA’s Perseverance rover is preparing samples that will later be returned to Earth sometime in the next decade. But how could these returned samples help improve our understanding of the habitability of Mars?

“There are so many questions that could be answered with a real piece of Mars, and the suite of samples that the rover collects is carefully selected to get a little bit of everything,” explains Dr. Day. “With real samples we can use many laboratory tools and methods that the rover does not have on board. The samples will give us a much clearer picture of what was happening on ancient Mars and where or how life might have survived.”

Was Mars capable of supporting life, even for a short time? What will current missions to the Red Planet continue to reveal, and what will we learn from the samples returned to Earth? These questions could well be answered within the next few years.

“There is a lot of speculation about whether or not there was life on Mars,” Dr Parris said. “If I could make a bet, I’d pick lava tubes as sites to look for life on Mars. Many of the lava tubes on Mars remain closed, which can serve as important sites for direct observation and study of Martian geology and geomorphology, as well as for revealing any evidence for the development of microbial life early in the natural history of Mars.

And with that, we wonder if Ares will finally answer “Are we alone?”

As always, keep doing science and keep looking up!

Featured Image: True-color image of the Red Planet taken on October 10, 2014, by India’s Mars Orbiter mission from 76,000 kilometers (47,224 miles) away. (Credit: ISRO/ISSDC/Justin Cowart) (This file is licensed under the Creative Commons Attribution 2.0 Generic License.)