Bernard M. Oliver Chair for SETI Research,
Location: Knight Studio, Newseum, Washington, D.C.
Date: Tuesday, September 16, 2014
Federal News Service
JILL TARTER: Well, it’s really my pleasure to be here this morning to discuss the motivations for space exploration, or at least my own personal reasons. I’ve spent my career trying to answer that very old question: Are we alone? And I explore space to understand the context of humanity. I’m curious about where we came from and where we might go from here. But above all, I think it’s really important that all of us become engaged in this exploration. We need to stretch ourselves and to internalize the deep time and the enormity of space. And in so doing, we can reimagine how we see ourselves and secure our own very long future.
So, in a very real sense, we are all the children of the universe. Our story began billions of years ago. The universe was created about 13.8 billion years ago, and our Milky Way galaxy was born 10 billion years ago. And you and I are intimately connected to those far away times and places. Humans trace their lineage not just back through the centuries of our families, not just back through the millennia of human civilizations with its buildings, its art and its many experiments with governance, not just back the millions of years since we diverged from the apes, not just back the 2.4 billion years over which the atmosphere of Earth has been profused with oxygen, thanks to the prodigious labors of cyanobacteria, not just back to the formation of our solar system and the sun, about 5 billion years ago, but all the way back to a supernova explosion, the death of a massive star about 8 billion years ago.
The iron atoms in the hemoglobin molecules of your blood were fused deep within a massive star that ended its life in a catastrophic convulsion, leaving behind remnants of stardust – remnants like this recent example – that are waiting to be incorporated into new generations of stars and plants and, perhaps, life.
It’s taken us millennia to piece together our story, and there’s so much more to learn. Our pathway to extend our understanding continues, and the exploration leads us to space.
And as we and our robots move off the surface of this planet, we have to avoid a tragedy of the commons in space. Once we thought that our continental territories were inexhaustible. We thought that the oceans were far too vast to be polluted. And we were wrong. And we need to avoid a similar degradation of the space environment. There are now hundreds of thousands of working spacecraft and derelict pieces of debris orbiting the Earth. In the sun-synchronous region of altitudes between 800 and a thousand kilometers, we may have already passed beyond the Kessler threshold, the point where if we don’t ever launch another satellite, the debris-debris collision will exponentiate and producing an impossible situation.
We need to be vigilant with our end-of-life protocols for spacecraft, and we must strive to clean up the trash that we’ve already left there if we don’t wish to lose the opportunity of launching safely off the Earth and onward on our exploratory path.
Now, I think very quickly that exploration could garner precious natural resources. And it could profoundly change the planet. Just imagine the geopolitical revolutions that will transpire as we begin to procure scarce minerals from asteroids rather than from the labors of oppressed miners. Imagine a future world safeguarded from civilization-ending impacts.
Will there be a place for humans in the future exploration of space? Well, yeah, of course there will. Just think about it. A robot took this image. And this image has thrilled and humbled every human who has ever been informed about its scientific meaning. But it took a human with a Hasselblad to compose this image, and this image grips the human psyche without any need for explanation or interpretation at all. This image connects directly with our emotions.
So, yeah, sure, robots can be cute. They can have their own Facebook pages. But they really cannot tell a good story. And actually, they’re a bit slow. So it’s pretty obvious that a human and robot partnership is the ideal mode of exploration, at least for our nearest worlds.
Now, in 2012, we lost a very singular human space explorer. And shortly before his death, Neil Armstrong reflected on the enduring impacts of the Apollo program. And there are his words: But I would say that it will enlighten the human race and help us all to comprehend that we are an important part of a much bigger universe than we can normally see from the front porch.
This is an all-important context for humanity. It’s the context within which my colleagues and I search for life beyond Earth. Most people in this room probably have their own reasons for exploring the solar system. My reason is to search for biomarkers of a second Genesis: another form of biology, extant or extinct, that’s unrelated to us. Another example of what the laws of physics and chemistry can create; an opportunity to tease apart what is necessary and what was contingent in our own origins.
And Mars is an excellent place to search for biomarkers. But so too are the watery oceans beneath the icy outer shells of Europa, Callisto, Ganymede, the large moons of Jupiter. Or even in the ethane lakes on the surface of Saturn’s large moon, Titan. Even, perhaps, on Saturn’s tiny little moon, Enceladus.
So there’s actually, really, no free lunch. But you know, the cryovolcanoes on the south polar regions of both Enceladus and Europa come pretty darn close. Straightforward fly-throughs of these geysers could capture samples of their buried oceans and any biology that they might contain for return to Earth, or Earth orbit, or the moon for detailed laboratory analyses. This would be a relatively easy mission.
And if terrestrial life turns out to be the singular form of .life in our solar system, we can then think about seeking out biosignatures in the atmospheres of distant exoplanets. Now, that ruddy glow away from the bright crescent of the moon, that’s actually earthshine. And the spectrum of earthshine demonstrates how dissimilar the atmosphere of our planet is from any other body that we’ve studied in the solar system. The absorption fingerprints of oxygen and ozone and methane reveal the extraordinarily disequilibrium chemistry that is sustained by methanogens and photosynthesizers that flourish on the surface of our planet.
When we talk about biosignatures, as yet there’s really no smoking gun biosignature. Not one particular thing that unambiguously says biologic rather than abiotic. And life as we don’t yet know it could have different biosignatures altogether. And the dominant biosignature will probably change over the time history of any distant world.
But biosignatures are indeed a worthy goal. The robotic search for biosignatures is not going to be easy or cheap. It’ll require large apertures in space and it won’t be accomplished quickly. But the search for life is one of those motivations for space exploration that can be sustained by the interest and the curiosity of the vast majority of people on this planet. And while we wait for the technology development that will enable the search for biosignatures, we can and we do search for technosignatures, evidence of intelligent technological species that modify their environments in ways that can be remotely sensed across the vast distances between the stars.
SETI searches today are ground-based. For example, there’s the Allen telescope array on the left and the Harvard optical sky survey on the right. And they’ll probably remain ground-based. But without doubt, they should be pursued collaboratively all around the globe. This is not something that we should be doing on our own. Our exploration will grow in power and – as collecting area increases and computational capacity improves. We’ll develop new ways to mine data collected for other purposes, and we’ll deploy new search strategies based on technologies that we haven’t even invented yet.
Phil Morrison, a very famous professor at MIT, called SETI the archaeology of the future. Any information-bearing signal that’s received would tell us about their past, but the fact of a successful reception of that signal tells us that we humans can have a long future.
So even if none of the searches succeed in the near future, SETI, I think, will still be one of the most extraordinary and profound endeavors of humankind. SETI and the process of orchestrating a global exploration of space for signs of life beyond Earth serve as a mirror, a mirror to show us ourselves from a new perspective in a larger context; a mirror that trivializes the differences among us. Helping us to see ourselves in this context of deep time and vast space is why the exploratory science of SETI is important to the long future of humanity.
That’s why I explore. That’s what space exploration has to offer to all of us.
Thank you. (Applause.)