ASU professors speak to Congress on importance of planetary sciences, exploration


September 10, 2014

Two Arizona State University professors from the School of Earth and Space Exploration provided congressional testimony, on Capitol Hill, Sept. 10, in support of NASA’s planetary sciences program.

Professors Jim Bell and Phil Christensen spoke about past successes and the continuing importance of exploring the solar system through NASA missions. They spoke before the Space Subcommittee of the Committee on Science, Space and Technology in the U.S. House of Representatives. ASU professors Phil Christensen and Jim Bell at Congressional committee hearing Download Full Image

The hearing was held to review numerous issues facing NASA’s exploration of the solar system, including the agency’s recent and proposed budget levels for planetary science, low inventories of Plutonium-238 for deep space missions, and possible new directions for future commercial interactions between NASA and space-related companies.

NASA has had an active solar system exploration program dating back to the 1960s. The program has turned in a number of successes in exploring the planets and other bodies in the solar system, helping us to learn more about our own planet and how we got here.

Both Christensen and Bell said recent cuts to the agency’s Planetary Science Division have dramatically slowed the pace of new missions and future discoveries, and have created an air of uncertainty in the program.

“Planetary science has excellent opportunities for continuing the exploration of our solar system into the future,” said Christensen, an ASU Regents' Professor who has 35 years experience in NASA planetary science missions. “These opportunities have been clearly defined in the recent NRC Planetary Science Decadal Survey, ‘Vision and Voyages in the Solar System,’ and they remain the same today.”

However, “significant reductions in the level of funding for NASA’s Planetary Science Division from the previous decade have dramatically slowed the pace of new missions and future discoveries,” he added. “The lack of year-to-year stability in funding is having a serious impact on the ability to develop a long-term plan for planetary exploration.”

“The future of planetary exploration has been severely undermined by disproportionate cuts initiated by the administration in recent years,” added Bell, who is also president of the Planetary Society, the world’s largest public space advocacy organization. “These cuts have dramatically reduced NASA’s ability to explore the solar system, and have forced the United States into a unilateral retreat from (exploration of) both the outer and inner solar system.”

Both Bell and Christensen spoke of the past successes in learning more about Mars, exploring the icy, ocean moons of the outer solar system, and in getting the first close-up glimpses of asteroids as important scientific milestones that should not be ignored.

However, in recent years the program has had to deal with many proposed cuts.

Starting with the FY13 budget request, Bell said, the administration requested a 21 percent cut in NASA’s Planetary Sciences Division, and it continued to target planetary science in its FY14 and FY15 budget requests, with overall funding some $230 million less than the previous decade’s average of approximately $1.5 billion per year.

“It is a worthy investment,” Bell said, adding that it takes less than 9 percent of NASA’s total budget "to maintain a peerless program of exploration that inspires the country, reveals the mysteries of our solar system as well as our home planet, and searches for hidden abodes of life in the worlds around us.”

Because planetary science missions take several years to conceptualize, design, launch and explore, Christensen said funding consistency is of prime importance to the success of the program.

“The uncertainties that exist in the year-to-year levels of support have made long-term planning extremely difficult,” Christensen explained. “Planetary missions require many years, or even decades, to plan, develop, implement and operate. Without stable funding, it is very difficult to implement these long-term missions, with the result that missions are either not begun or their development is extended, with a resultant increase in mission cost.”

For Bell, who will lead development of the camera system on the Mars 2020 rover, the fact that the technology is there and the desire to learn more about our home planetary system is evident. We are at the dawn of a new age in space exploration.

“For the first time in human history, our ambition is no longer bounded by limits in technology, but by self-imposed limitations on resources,” he added.

Director, Media Relations and Strategic Communications

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ASU astrophysicists to probe how early universe made chemical elements


September 10, 2014

In the beginning, all was hydrogen – and helium, plus a bit of lithium. Three elements in all. Today's universe, however, has nearly a hundred naturally occurring elements, with thousands of variants (isotopes), and more likely to come.

Figuring out how the universe got from its starting batch of three elements to the menagerie found today is the focus of a new Physics Frontiers Center research grant to Arizona State University's School of Earth and Space Exploration (SESE). The grant is from the National Science Foundation's Joint Institute for Nuclear Astrophysics – Center for the Evolution of the Elements. Of the full $11.4 million NSF grant, about $1 million will come to ASU over five years. Massive star Eta Carinae ASU astrophysicists have received an important research grant to study how massive stars, such as Eta Carinae depicted here, evolve and eventually seed the universe with heavy elements created by nuclear reactions inside them. Image by Nathan Smith (UC Berkeley)/NASA Download Full Image

SESE astrophysicist Frank Timmes is the lead scientist for ASU's part of the Physics Frontiers Center research project. Timmes, ASU's director of advanced computing, focuses his astrophysical research on supernovae, cosmic chemical evolution, their impacts on astrobiology and high-performance computing. He is also a scientific editor of The Astrophysical Journal.

The evolution of elements project also includes Michigan State University in Lansing (the lead institution), the University of Notre Dame in South Bend, Indiana, and the University of Washington in Seattle.

Joining Timmes on the project will be astrophysicists Patrick Young, Evan Scannapieco and Sumner Starrfield, also from the School of Earth and Space Exploration In addition, the award will fund two postdoctoral researchers to collaborate on the effort.

Take it from the top

Time started 13.7 billion years ago with the Big Bang, which produced the basic three elements. Yet by the time the Bang was a billion years old, essentially all the other chemical elements we know had formed. How did this happen?

"It takes place inside stars," says Timmes. "They're the element-factories of the universe. They take light stuff, such as hydrogen and helium, process it in nuclear reactions, and then crank out carbon, nitrogen, oxygen and all those good things that make you and me."

While the broad outline is clear, details are a lot murkier, he says, and that's where ASU's researchers enter the picture.

"ASU's contribution is to provide the glue between experimental low-energy nuclear astrophysics measurements and astronomical observations of stars," Timmes says.

Ancient stars were fundamentally different from those today, he notes, because they started off with a different collection of initial ingredients – no heavy elements. But those first-generation stars are gone.

As Timmes explains, "The stars that began back then went through their life cycles and died, so we naturally don't directly see them today. But when they died, they exploded and threw out little bits of carbon, oxygen and nitrogen, which ended up in the next generation of stars."

Round and round in cycles

In a process that still continues today, massive stars create more and more complex elements, then explode as supernovas and scatter the newly created elements into space for another generation of stars to use. Cycle after stellar cycle, stars became steadily richer in heavier and more complex elements.

The sun, its planets and moons all formed about 4.5 billion years ago. Most of the elements they contain didn't exist when the universe was young, so what generation does the sun belong to?

Timmes explains, "A typical massive star, in round numbers, lives about a million years. The Big Bang occurred about 7 billion years before the sun formed. I need a thousand generations of massive stars to get us to a billion years, so I need on the order of 10,000 generations of massive stars to get one with the sun's composition.

"We are the product of many, many, many previous generations of stars."

The researchers at the School of Earth and Space Exploration plan to develop computer models of stars of all sizes, masses and chemical compositions, then set them on their life courses. It's building stars in computers and comparing them to observations of stars to see how the universe builds them for real.

"The toughest theoretical problem we have to work on is how stars explode," says Timmes. "In a loose, hand-waving sense, we know that stars explode, of course, but exactly how it happens isn't well-known or understood."

The new research project fits well with the expertise of the school's astrophysicists. And there's another plus as well. With this project, ASU is joining a small group of research centers that deal with "Frontiers Physics." The entire country has only about ten such centers, Timmes explains. Highly competitive and highly sought-after, they cover subjects such as biological physics and theoretical physics.

But there's just one nuclear astrophysics center, he says. "And it's great that ASU is going to play a key role in it."

Robert Burnham

Science writer, School of Earth and Space Exploration

480-458-8207