Life on Mars?

1. Life on Mars? 19 February 2019

2. Are we alone? • Life arose quickly on Earth, around 4 billion years ago • Star formation makes planets, too: they should be common • Impacts can frustrate life, but it recovers • Extreme life forms ‘like it hot’ and may have arisen first on ocean bottoms • Moons also have heat sources

7. Urey-Miller Experiment

12. The Drake Equation

13. From the Wall Street Journal:

14. The Drake equation applied to finding a girlfriend in Philadelphia: Also, in this case, probabilities are too uncertain! Get empirical evidence.

19. Still operating!

21. Photos From the Opportunity Rover’s Mission on Mars Today’s New York Times Tuesday Science Section Scenes from a long drive on Mars. Clockwise from top left: a raised section of the western rim of Endeavour Crater; tracks along a sand ripple; a view of the plain after a drive in 2011; and the edge of Santa Maria crater.

22. The panorama was taken on Opportunity's first day on Mars. The small depression was named Eagle Crater. The rim of the crater is about 30 feet from the rover. CreditNASA/JPL/Cornell

23. Blueberries everywhere In Eagle Crater, the small crater that Opportunity landed in, the rover found this cluster of spheres nicknamed blueberries embedded in the rock, like blueberries in a muffin.

24. Greater craters This cliff of layered rocks, part of a promontory named Cape Verde, was about 165 feet from the rover and about 20 feet tall. CreditNASA/JPL/Cornell

25. Opportunity’s last stop Opportunity took this panoramic picture overlooking Perseverance Valley in June 2017. A year later, partway down the valley, it was engulfed by a global dust storm that ended the rover's mission.CreditNASA/JPL-Caltech

26. NASA’s Mars Rover Opportunity Concludes a 15-Year MissionSilent since a giant dust storm last summer, the rover was the longest-lasting robot on another planet ever The shadow of NASA’s Opportunity rover on the Martian surface in 2004. The rover was designed for 90 days of exploration, but remained functional for more than 5,000 Martian days

27. A Large Body of Water on Mars Is Detected, Raising the Potential for Alien Life • Italian scientists working on the European Space Agency’s Mars Express mission announced on Wednesday that a 12-mile-wide underground liquid pool — not just the — had been detected by radar measurements near the Martian south pole. • The discovery suggests that the liquid conditions beneath the icy southern polar cap may have provided one of the critical building blocks for life on the red planet.

30. MSL Objectives Mars Science Laboratory is a rover that will assess whether Mars ever was, or is still today, an environment able to support microbial life. In other words, its mission is to determine the planet's "habitability."

32. NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill. "This temporary increase in methane -- sharply up and then back down -- tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, a member of the Curiosity rover science team. "There are many possible sources, biological or non-biological, such as interaction of water and rock."

33. Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites. Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

34. Cumberland' Target Drilled by Curiosity NASA's Mars rover Curiosity drilled into this rock target, "Cumberland," during the 279th Martian day, or sol, of the rover's work on Mars (May 19, 2013) and collected a powdered sample of material from the rock's interior.

35. Summary: Life • Life is a chemical process that includes metabolism, growth and reproduction. • All life on earth evolves • The 3 requirements for life: biogenic elements (SPONCH), water and energy • Earth life is based on carbon and requires liquid water • The range of distance where a planet can have liquid water on its surface is the ‘habitable zone’

36. More Summary: Life • Large impacts can destroy life forms or even sterilize the planet. Jupiter protects Earth from asteroid impacts. Life changes the planet • All Earth life is related, sharing the same DNA. It likely arose from a single ancestor • If other planets are like Earth, life could be common. Meteorites can transfer life. • The Drake equation calculates the number of technical civilizations we might communicate with

37. Life on Mars? • Details of life’s origin on Earth are lost • Mars had liquid water, biogenic elements, energy when the first life arose on Earth • Life from Earth? Ejected material can reach Mars (opposite of Mars meteorites) • Life on Mars could still survive in some locations: hot springs or underground. ‘Follow the water’ • Vikings searched for life similar to Earth, but did not find it

38. Where to search for life • Lake beds • Hydrothermal sites • Recent floods • Underground • Earlier life? If now extinct, look for fossils… • Enough energy? Yes, for 1-2 ft of life! • Conclusion: No conclusion… Look harder, follow the water, Mars still most Earth-like