Joint Dark Energy Mission

One way to hide something is to throw a blanket over it. Nature hides much of the universe behind a blanket of air — Earth’s atmosphere. The atmosphere blurs the view of astronomical objects, and it prevents most forms of energy from reaching the surface. The only unfettered view of the universe comes from space, high above Earth’s protective blanket of air. And that’s the reason for the Joint Dark Energy Mission (JDEM), a project that will place a dark energy-searching telescope in space.

Artists’ concepts of Destiny (top), SNAP-L.

NASA and the Department of Energy are collaborating on the satellite project, which will launch no earlier than 2017. The agencies will consider missions proposed by several research groups. At least four groups, including the two that discovered dark energy, are developing mission concepts.

Some of the missions would probe dark energy by studying the exploding stars known as Type 1a supernovae. Each mission also will use a second technique to test dark energy, either gravitational lensing or baryon acoustic oscillations. Both techniques look at the way galaxies are distributed through the cosmos as probes of the effects of dark energy.

Each mission will use large CCDs, like the chips in digital cameras and cell phones, to examine large areas of the sky. And their cameras will be sensitive to infrared light, which is absorbed by water vapor in the atmosphere. The expansion of the universe has stretched the light of many early galaxies to infrared wavelengths, so the space-based telescopes will be able to detect many galaxies that are hidden from ground-based instruments.

Proposed JDEM Missions

Advanced Dark Energy Physics Telescope (ADEPT)

Cosmic Inflation Probe (CIP) or Cosmic Expansion Probe (CEP)

Dark Energy Space Telescope (Destiny)

SuperNova Acceleration Probe-Lensing (SNAP-L)

Additional Resources

JDEM website