When trying to envision life on other worlds, scientists need only look to one planet for inspiration: Earth.
The search for life beyond our world, what might constitute life elsewhere in the universe and whether mankind should colonize other planets were discussed by leading scientists and members of the public in the first of three Saturday meetings offered as part of the Brilliant! Science festival on extraterrestrial life at the California Academy of Sciences.
The informal discussion held Sept 28 featured researchers Carl Pilcher retired head of NASA’s Astrobiology Institute, David DesMarais from NASA’s Ames research facility and academy fellow, former Apollo 10 astronaut Rusty Schweickart, and was moderated by Jill Tarter, Bernard Oliver Chairwoman of the SETI (Search for Extraterrestrial Intelligence) Institute.
Terry Gosliner the academy’s Dean of Science and Senior Curator of Invertebrate Zoology told the group the event was part of the academy’s efforts to better connect people with science.
“One of the ideas we came up with was having conversations rather than just sitting having a lecture,” he said, “Being able to sit down and talk about what is controversial what we don’t know about, what is provocative and how science can answer some of the questions to which we don’t have answers.”
A habitable planet that could support life as we know it was referred to as “Earth 2.0” during the discussion.
Schweikert is the Chairman Emeritus of the B612 Foundation, which hopes to launch a satellite to track the orbits of asteroids that could collide with the earth.
His fundamental loyalty is to life, Schweikert said, specifically the process of evolution which has brought mankind to its current state.
“That’s what is really valuable, “he said. “More than my life, more than your life, collectively this for many of us is the highest ultimate value, preservation of this process called evolution.”
When trying to determine how life would exist on other planets, Astrobiologists like Pilcher examine organisms that live under extreme conditions throughout the world.
Though it was once thought that all life depended on sunlight and biosynthesis, researchers have found thriving ecosystems on hydrothermal vents deep in the ocean where sunlight does not exist, Pilcher said.
A microbial ecosystem found in a South African gold mine survives without photosynthesis and doesn’t even need oxygen, unlike the deep ocean vent system.
Take that system and transplant it to the subsurface of Mars and you could have life on another world, Pilcher said.
“So we learn by studying life on earth that the subsurface of Mars in in principle habitable,” he said.
Perhaps the biggest potential discovery awaiting scientists would be finding a form of life created from biochemistry different from that found in humans and all other earth life forms.
“If we find an earth 2.0 that has life with a separate origin, then we would have made one of the most profound discoveries in all human existence and we will begin to understand the fundamental nature of life and our relationship to the universe,” he said.
DesMarais looks to geology and the history of the earth’s formation to find answers about what life might exist on other worlds.
Plants and other life forms are products of their history on a planet and differences in the geologic processes and other factors can determine the outcome, he said.
“Just the history of (asteroid) impacts can make two planets different,” he said.
The quest for life is fundamental to the work of the academy, Goslinger said. Expeditions to Madagascar and the Philippines help academy scientists learn more from biological hot spots where life is very diverse, though science has identified only 10 percent of the species that inhabit the earth.
“The more we know about how other systems beyond work, it tells us more about how systems here work, how they are different and how they are similar, “he said.
When deciding if humans should colonize other planets, mankind must resist the attitude that energy and other resources on earth can be used up because we have found another place to live, Goslinger said.
“It’s something we need to fundamentally squelch, in our need to disperse, “he said. “We have a moral obligation to preserve life on earth and it’s in our own best interests as well.”
Discovering life on other planets will take technology but will also take a certain amount of luck, Pilcher said.
Oxygen is a significant factor in searching for life, but the Earth did not have an oxygen atmosphere for its first two billion years, he said.
Schweikert is convinced there is life on other planets but Tarter said researchers must have more proof.
“The universe is looking more bio friendly but that doesn’t mean it’s inhabited,” she said.
Asked why humanity care so much about looking for extraterrestrial life, Tarter said the search causes humans to expand their thinking beyond the here and now.
“In asking these questions it sort of holds up a mirror to us all,” she said.
“One of the things it says is ‘you guys, you are all the same when compared with something that could have a separate evolutionary history out there.’”
“And that you-are-all-the-same-message is something that we have to learn and we have to stop fighting each other over perceived trivial differences.”
The next discussion “Cosmic Evolution: A Scientific Creation Myth like No Other,” will be held from 9:00-10:30 a.m. Saturday, October 12 at the academy.
Speakers will be David Morrison, Director of the Carl Sagan Center for the Study of Life in the Universe, at the SETI Institute and Eugenie Scott, Executive Director, National Center for Science Education. Tarter will moderate with a welcome address by Goslinger.
For more information visit: http://www.calacademy.org/brilliantscience
Admission is $35 for adults, and $25 for members and seniors. Coffee, tea and pastry are provided. Ticket does not include museum admission. Reserve a Member or Non-Member ticket online or over the phone at 1-877-227-1831.