Is There Life on Mars?

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Matt O'Dowd (0:48)

Has there ever been life on Mars? No, probably not.

Maybe?

SPEAKER_2 (0:55)

I don't know.

Matt O'Dowd (1:02)

There is no greater hero in our search for life on Mars than a little robot named Opportunity. Fifteen years after its mission began, 57 times longer than it signed up for, Opportunity has gone silent. As we wait and hope while NASA races to reestablish contact, we thought we'd reflect on the greater quest that Opportunity has contributed so much to. The search for life on Mars.

Mars, the red planet, fourth rock from the sun. It's currently just past its closest approach to Earth, making it an angry red eye in the early night sky. This is a planet that, as far as we know, is inhabited. Entirely by robots. But at the end of July, something remarkable was announced that may prove the possibility of life on Mars. There's a giant underground lake of liquid water. Right now, under the South Pole. And in 2020, the rates to find life on Mars will intensify, with both ESA and NASA launching missions. They'll shift the focus from the search for water, because we now know there is water, to the search for life, past or present. NASA's also planning a mission to take a sample of Martian soil and rocket it back to Earth. Applying our best earthbound technologies to an uncontaminated sample may provide the proof of Martian life we've always been hoping for. But as good scientists, we have to suggest some caution, because people have been searching for life on Mars and believing they've found it for over 300 years. So today, we're going to look back at the long history of life on Mars, or at least of our hunt for it. We begin our story at the end of the 17th century, when Dutch polymath, Christian Huygens, made amazing advances on Galileo's Astronomical Telescope. This allowed him to observe a dark patch on the Martian surface and so measure Mars' 24-hour rotation rate, as well as a white spot on its south pole. He guessed that both of these resulted from surface water, clouds, and ice.

Huygens saw this as evidence that Mars was habitable and so perhaps inhabited. In fact, he was the first to postulate that liquid water is necessary for life. A few centuries of extra science has only convinced us further of this, as we've discussed before.

Huygens was a visionary in many ways, but only half right in his interpretation of his observations of Mars. The white spot was indeed a polar ice cap, but the dark spot was probably the volcanic rock of the Certus Major Planum. Nonetheless, the prospect of a watery Mars kicked off centuries of optimism for an inhabited planetary neighborhood. Astronomer Giacomo Maroldi quickly followed Huygens and in the early 18th century discovered ice caps on both poles, correctly inferring their nature. Later that century, William Herschel watched the ice caps grow and shrink annually and thought he saw what he calls a comfortable but modest atmosphere. Herschel generously decreed of Mars that its inhabitants probably enjoy a situation in many respects similar to ours.

Now, Herschel was a fantastic astronomer, but his wrongness about Mars' atmosphere is a nice example that even the smartest of us see what we want to see. As a scientist, it's so important to stay aware of that very human bias because it's led to the erroneous discovery of life on Mars on multiple occasions.

Fast forward to 1877 Giovanni Schiaparelli was studying Mars during its perihelion position. That's the configuration that also just passed.

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Propel Fitness Water. With Gatorade Electrolytes, Zero Sugar and Vitamins. Propel Hydrates Better Than Water. To help you get the most out of your workout and get back to your best self. What propels you? Propel with Gatorade Electrolytes.

SPEAKER_2 (5:01)

When you need to build up your team to handle the growing chaos at work, use Indeed Sponsored Jobs. It gives your job post the boost it needs to be seen and helps reach people with the right skills, certifications and more. Spend less time searching and more time actually interviewing candidates who check all your boxes. Listeners of this show will get a $75 sponsored job credit at indeed.com/podcast. That's indeed.com/podcast. Terms and conditions apply. Need a hiring hero? This is a job for Indeed Sponsored Jobs.