Panel Urges NASA to Study Dark Energy

A supercomputer-produced cross-section of part of the universe shows galaxies as brighter dots along filaments of matter, with a sea of dark energy filling in between the galactic islands. CREDIT: James Wadsley, McMaster University, Hamilton, Ontario

A proposed NASA mission to study a mysterious force thought to be accelerating the expansion of the universe should be the first in the agency's "Beyond Einstein" program to be developed and launched, the National Research Council recommended today.

Beyond Einstein is NASA's research roadmap for five proposed space missions set to begin in 2009 that will study areas in science that build on and extend the work of physicist Albert Einstein.

The missions include Constellation-X and the laser Interferometer Space Antenna (LISA), which will measure X-rays and look for hypothetical gravity waves, respectively, as well as the Inflation Probe (IP), the Black Hole Finder Probe (BHFP) and the Joint Dark Energy Mission (JDEM).

The National Research Council report recommended that JDEM be the first mission to be deployed since it is already in the prototype phase and will require less development than the other missions.

"All of the mission areas in the Beyond Einstein program have the potential to fundamentally alter our understanding of the universe," said committee co-chair Charles Kennel of the University of California, San Diego. "But JDEM will provide direct insight into a key Beyond Einstein science question, and it is the most technically feasible option for immediate development."

'Lambda'

Dark energy is a mysterious force scientists think is speeding up the expansion of spacetime and constitutes some three-quarters of the density of the universe.

It was initially proposed by Einstein as a counterforce to the gravitational attraction of matter to explain why the universe appeared static, neither growing nor shrinking. But he later dismissed his idea as a mistake when observations by astronomer Edwin Hubble revealed the universe was in fact expanding.

Dark energy, which Einstein called lambda, was revived in the late 1990s when astronomers discovered that the universe was not only expanding, but expanding at an accelerated clip.

Gravity waves

The report also recommended that LISA become the flagship mission of the program and that more money be funneled into the project because it could provide an entirely new way of observing the universe. However, the report committee believes that more testing is required before it launches. Specifically, the mission must await the results of the LISA Pathfinder mission in 2009 that will test some of the critical technologies to be used in the final LISA mission.

The report was sponsored by the U.S. Department of Defense and NASA. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.

• Top 10 Strangest Things in Space
• VIDEO: Black Hole: Warping Time & Space
• Gravitational Waves: Einstein's Elusive Children