NASA and the Department of Energy are working together to build the first space-based observatory designed to understand the nature of dark energy.One of the most significant scientific findings in the last decade was that the expansion of the universe is accelerating. The acceleration is caused by a previously unknown dark energy that makes up approximately 70 percent of the total mass energy content of the universe.
The discovery of dark energy showed that empty space is filled with a mysterious energy that increases as the universe expands. While Einstein initially proposed a cosmological constant that could explain the dark energy, it is the amount of dark energy that is difficult to understand.
Now, a new collaborative research project between NASA and the DOE called the Joint Dark Energy Mission (JDEM) will hopefully clarify some of the properties of dark energy, advancing foundational elements of physics and astronomy.
“Understanding the nature of dark energy is the biggest challenge in physics and astronomy today,” said Jon Morse, director of astrophysics at NASA in a statement. “JDEM will be a unique and major contributor in our quest to understand dark energy and how it has shaped the universe in which we live.”
Both DOE and NASA will develop scientific instrumentation for the observatory and will participate in the science operations and data analysis phase of the mission. NASA will provide the telescope, spacecraft bus, and launch services.
Scientists hope that the JDEM, along with future measurements of supernovae, gravitational lensing and clusters of galaxies from a Large Synoptic Survey Telescope will reveal definitively whether dark energy behaves like Einstein’s cosmological constant or like some new substance that changes with time as the universe evolves. There are nearly 30 experiments proposed or under way.
With launch costs, NASA hopes the total budget for JDEM will fall under $1 billion. In a sign that physicists and astronomers have longer planning horizons than most, launch is planned for the middle of next decade. But if JDEM looks to be more expensive, the project may have to be postponed.