Uploaded July 2026 | Updated September 2026, 2 weeks ago
AD | Go to https://ground.news/drbecky to stay fully informed with the latest Space and Science news. Save 40% off the Vantage plan through my link for unlimited access.
It would take a near miracle for there not to be life on Mars. Mars and Earth have been “swapping spit” for billions of years; anytime either planet is hit by comets or asteroids, some material gets ejected into space, with a tiny fraction of that material eventually landing on the other planet.
If any of Earth’s microbes happen to have been hitch-hiking in that material, then you’ve got potential life on Mars. And we know that life is capable of surviving both the vacuum of space, and a simulated Martian environment in a lab.
And we know that Mars didn’t used to be the dry, arid world it is today. Water once flowed on Mars back before it lost its atmosphere to space.
And yet we still haven’t found any direct evidence for life on Mars. Or have we? Because 50 years ago this month, one of the experiments on NASA’s Viking lander that was designed to search for signs of life returned a positive result. It’s just that other experiments on Viking returned a negative result.
The next few years saw arguments go back and forth in the scientific research papers, could the results be explained by biology or just chemistry, all asking the same question: is there life on Mars? In this video, we are going to dive into this question!
Papers mentioned:
Biemann et al. (1976) - Paywall - science.org/doi/10.1126/science.194.4260.72
Horowitz, Hobby & Hubbard (1977) - Paywall - agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/JS082i028p04659
Klein et al. (1976) - Paywall - science.org/doi/10.1126/science.194.4260.99
Levin & Straat (1976a) - link.springer.com/article/10.1007/BF00926948
Levin & Straat (1976b) - Paywall - science.org/doi/10.1126/science.194.4271.1322
Levin & Straat (1981) - Paywall - ntrs.nasa.gov/citations/19810053555
Levin & Straat (2016) - pmc.ncbi.nlm.nih.gov/articles/PMC6445182
Oyama & Berdaahl (1977) - Paywall - agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/JS082i028p04669
00:00 - Introduction
03:49 - I - What were the Viking landers?
07:06 - II - Did Viking find evidence for life on Mars in the 1970s?
13:34 - III - Why the interpretation of the results was so controversial
15:45 - IV - Have we found any evidence for life on Mars since Viking?
20:02 - Bloopers
Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: martino.freelance@gmail.com
Video produced by Marina Hui & Dr Becky Smethurst
---
📚 My book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): lnk.to/DrBecky
---
👕 My merch, including JWST designs, are available here (with worldwide shipping!): dr-becky.teemill.com
---
🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive
---
🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video!
---
👩🏽💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.
drbecky.uk.com
AD | Go to https://ground.news/drbecky to stay fully informed with the latest Space and Science news. Save 40% off the Vantage plan through my link for unlimited access.
It would take a near miracle for there not to be life on Mars. Mars and Earth have been “swapping spit” for billions of years; anytime either planet is hit by comets or asteroids, some material gets ejected into space, with a tiny fraction of that material eventually landing on the other planet.
If any of Earth’s microbes happen to have been hitch-hiking in that material, then you’ve got potential life on Mars. And we know that life is capable of surviving both the vacuum of space, and a simulated Martian environment in a lab.
And we know that Mars didn’t used to be the dry, arid world it is today. Water once flowed on Mars back before it lost its atmosphere to space.
And yet we still haven’t found any direct evidence for life on Mars. Or have we? Because 50 years ago this month, one of the experiments on NASA’s Viking lander that was designed to search for signs of life returned a positive result. It’s just that other experiments on Viking returned a negative result.
The next few years saw arguments go back and forth in the scientific research papers, could the results be explained by biology or just chemistry, all asking the same question: is there life on Mars? In this video, we are going to dive into this question!
Papers mentioned:
Biemann et al. (1976) - Paywall - science.org/doi/10.1126/science.194.4260.72
Horowitz, Hobby & Hubbard (1977) - Paywall - agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/JS082i028p04659
Klein et al. (1976) - Paywall - science.org/doi/10.1126/science.194.4260.99
Levin & Straat (1976a) - link.springer.com/article/10.1007/BF00926948
Levin & Straat (1976b) - Paywall - science.org/doi/10.1126/science.194.4271.1322
Levin & Straat (1981) - Paywall - ntrs.nasa.gov/citations/19810053555
Levin & Straat (2016) - pmc.ncbi.nlm.nih.gov/articles/PMC6445182
Oyama & Berdaahl (1977) - Paywall - agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/JS082i028p04669
00:00 - Introduction
03:49 - I - What were the Viking landers?
07:06 - II - Did Viking find evidence for life on Mars in the 1970s?
13:34 - III - Why the interpretation of the results was so controversial
15:45 - IV - Have we found any evidence for life on Mars since Viking?
20:02 - Bloopers
Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: martino.freelance@gmail.com
Video produced by Marina Hui & Dr Becky Smethurst
---
📚 My book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): lnk.to/DrBecky
---
👕 My merch, including JWST designs, are available here (with worldwide shipping!): dr-becky.teemill.com
---
🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive
---
🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video!
---
👩🏽💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.
drbecky.uk.com
