The NASA and DOE Dark Energy Mission
Dark energy was discovered in 1998 by Department of Energy- and NASA-funded scientists working at the Lawrence Berkeley National Laboratory and other institutions. It was named by Science magazine that year as the scientific breakthrough of the year. Dark energy is the name given to the cause of the accelerating expansion of our Universe and comprises more than 70% of the total mass and energy of the Universe. Yet, what it is and how it behaves is a complete scientific mystery.
The goal of the Joint Dark Energy Mission is to explore the properties of dark energy and measure how cosmic expansion has changed over time. The JDEM observatory is comprised of a large-aperture optical/near-infrared wide-field telescope operating in space, allowing scientists to study the cosmic acceleration using multiple techniques. Dark energy was first discovered by observing explosions called Type 1a supernovae. By observing Type Ia supernovae both near and far, scientists can map out their distances and the cosmic expansion. Other methods, such as gravitational weak lensing and baryon acoustic oscillations, measure the shapes and clustering pattern of distant galaxies and search for the imprint of the cosmic acceleration in their distribution and evolution.
JDEM is a partnership between NASA and the DOE. The two agencies will work together to develop the science and the instrumentation to carry out the space-based dark energy investigation. Both NASA and DOE will participate in data analysis and science operations. LBNL has lead responsibility for the DOE work. The Mission will be managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Because understanding dark energy is a high scientific priority for both agencies, JDEM has been formulated as a joint strategic mission. The project is now in the conceptual design phase and has a target launch date of 2016.