Rep. John Culberson, the powerful chairman of the House subcommittee that doles out and directs funding each year for NASA, convened a hearing focused on NASA’s quest to discover extraterrestrial life on a set of moons orbiting Jupiter and Saturn known as “ocean worlds.” Culberson is betting on Jupiter’s moon Europa as a likely candidate for a second home for life within our solar system.
“Today, we're here to talk about the search for life beyond earth, the search for earth-like planets,” explained Rep. John Culberson (R-TX), the chairman of the House Appropriations Subcommittee on Commerce, Justice and Science, in his opening statement of a two-hour hearing devoted to the search for extraterrestrial life, especially on the so-called ocean worlds of our solar system. During the March 3 hearing, Culberson revealed a determination to focus NASA on its quest to find evidence for life elsewhere in the universe.
A longtime champion of NASA whose congressional district resides in the Houston metropolitan area, home to Johnson Space Center, Culberson spoke of NASA’s planetary science efforts in glowing terms and expressed palpable excitement for the topic at hand:
We live in an extraordinary time where the scientific community has revealed to the world that there are as many earth-like planets as there are stars in the sky. The amazing discoveries that Kepler [space observatory] has made…and the possibility for life on those other worlds and indeed within our own solar system has become very, very real.
In his opening statement, subcommittee ranking member Mike Honda (D-CA) nearly matched Culberson in his fascination with the scientific questions behind the search for extraterrestrial life:
The extreme diversity and resilience of life on earth has shown us that…wherever there's water, organic compounds, and energy, there is life.
The two witnesses at the hearing were Charles Elachi, director of NASA’s Jet Propulsion Laboratory (JPL), and astrobiology expert Jonathan Lunine, director of the Cornell Center for Astrophysics and the Planetary Society.
Culberson warms up to the icy worlds of the solar system
Culberson expressed confidence that if life is to be found in the solar system, it will most likely be on one of the ocean worlds orbiting Jupiter and Saturn, a category of moons that scientists recently discovered contain large, stable bodies of liquids. Lunine shared that, thanks to recent NASA and European Space Agency missions to Jupiter (the Galileo Orbiter) and Saturn (Cassini & Huygens), planetary scientists are nearly certain that at least three of these worlds contain large salt water oceans: Europa orbiting Jupiter as well asEnceladus & Titan orbiting Saturn.
The growing scientific attention to such ocean worlds led Culberson to call for a new Ocean Worlds Exploration Program in the committee report that accompanied the House subcommittee’s fiscal year 2016 appropriations bill. Culberson said he has leaned on the National Academy of Sciences’ 2013-2022 Planetary Science Decadal Survey in helping him understand and direct mission priorities, and shared that it has influenced his thinking with regards to Europa as his top priority. He added, “the Decadal Survey in my mind has always been the gold standard that NASA should follow.”
The 2013-2022 decadal survey elevates a Jupiter Europa Orbiter as the second highest priority flagship mission of the decade. Culberson touts the moon as pivotally important on his congressional website, asserting his belief that Europa’s “immense” undersurface ocean is where we will first find life on another world.
A focus on Europa, but life may also be waiting on other ocean worlds
As a result of Culberson’s leadership, the joint explanatory statement accompanying the final 2016 appropriations law directs NASA to provide $175 million “for the Jupiter Europa clipper mission… [which] shall include an orbiter with a lander that will include competitively selected instruments…with a target launch date of 2022.” What is not as clear, however, is whether 2022 is feasible as a launch date for both an orbiter and a lander.
In his testimony, Elachi said that getting to a place where NASA can examine Europa’s oceans for the presence of life will require three major steps, each its own mission. The first is to send “an orbiter which will map the surface of Europa at very high resolution and sound so we can determine how thick [the ice] is,” the second is to “put a modest lander on the surface, so we can determine the characteristics of that ice,” and the last is to “create a submarine…to melt our way and go below the surface.” Elachi later warned that the present level of funding is not sufficient to achieve a launch for even the first mission by the early 2020s.
If finding extraterrestrial life is the goal, the scientific community is also not in agreement that Europa offers the best prospect. While Lunine agreed that Europa is a “top candidate” for the discovery of life, he indicated that Titan and Enceladus are also prime candidates and should not be overlooked.
Titan, said Lunine, has large lakes of liquid hydrocarbons and all of the formal requirements for life, albeit methane-based life: abundant organics, liquids, and sources of energy. And, as he continued, Lunine seemed to imply that Enceladus, not Europa, is the most likely candidate for hosting extraterrestrial life in the solar system:
Thanks to the prodigious capability of its instruments, its chemical sniffers, Cassini has found not only water ice, and water vapor, but also organic molecules, salt dissolved in the water, tiny grains of silica, all indicators that inside Enceladus, down in this small, liquid water, salty ocean is a hydrothermal system, a place in which water, organics, and minerals are heated together in the kind of chemical stew that many scientists think was the place where life began on Earth four billion years ago. … And so, if you look at all the requirements for terrestrial-type life – liquid water, organics, minerals, energy, chemical gradients, Enceladus has it all.
Culberson shooting for the stars, Elachi says they are within our grasp
Channeling a pioneering spirit, Culberson is setting his sights on the outer reaches of the human imagination and ambition in space, encouraging NASA to think boldly and generations ahead in its vision.
During the question and answer session, Culberson argued that the discovery of life on another world ought to be one of NASA’s and our nation’s priorities, because it will be a “transformational moment in human history” that will again reconfirm the value of NASA and our scientific enterprise, much like when Neil Armstrong walked on the moon. It will “galvanize the country and the world and certainly encourage the nation to take NASA even further…[and] make sure the American space program is the best in the world.”
To Culberson’s delight, Elachi signaled that NASA very well may be able to deliver on such a bold vision:
For the first time in human history, we have the technology and the capability to explore for life in our solar system and beyond.