February 13, 2013
US Team Begins Work On New Dark Matter Detector
John P. Millis, Ph.D. for redOrbit.com — Your Universe Online
In order to illuminate the darkness we turn to the light. Whether the sun, a lamp, or a candle, we rely on electromagnetic radiation to reveal the world, and indeed the Universe, around us.
Everything that we see - every tree, every planet, and every star - we see because it emits, reflects, bends and focuses light to our eyes. Without the interaction of matter with light, we are blind.
But what about matter that does not interact with light? If such matter exists, we would have to develop new ways of seeing and interpreting the heavens.
The Dark Universe
In the last several decades our understanding of the shape, scale, and evolution of the Universe has been shaken. Galaxies were found to not rotate the way they “should.” While the very expansion of space-time itself seemed to be accelerating, contradicting Einstein´s field equations.
Could our theories of the Universe be wrong? Or could a mysterious dark universe lie beneath the surface of the glowing sky we have known for millennia?
While no consensus has been drawn, the popular opinion is that two forms of energy, foreign to the usual baryonic matter that we experience directly, fill the vast majority of the Universe.
It seems that no more than a few percent of the Universe we can see is light and normal matter — protons, neutrons, and electrons. Nearly 24 percent is, instead, dark matter - interacting with all other matter gravitationally, but not electromagnetically; blinding us to its presence.
The rest, some 73 percent, of the Universe is simply known as dark energy — a gentle breeze that permeates the entire Universe, pressing against the very fabric of the Universe to drive its expansion.
Seeing In The Dark
Neither dark matter nor dark energy can be directly seen, only inferred by monitoring how it interacts with matter and space-time. To accomplish this, a new telescope is being developed in a joint venture between the European Space Agency (ESA) and NASA.
The craft will orbit the Sun on a path a million miles from the Earth — more than 4 times the distance to the Moon. While it will makes its trip around the Sun once a year — just like the Earth — it won´t orbit the Earth the way the Moon or most satellites do.
Here, away from the influence of Earth´s atmosphere and other contaminations, the observatory, known as Euclid, can get a clear glimpse of the dark universe. To do this, Euclid will take two kinds of measurements.
The first involves studying billions of galaxies spread over a third of the entire sky. Looking back over how galaxies have moved over the last 10 billion years researchers can create a detailed map of how dark matter is distributed in galaxy clusters.
This method, known as weak lensing, is accomplished by taking extremely accurate images of the galaxies and studying how the interlaying dark matter creates distortions of their light.
Such clues will reveal details about the nature, and possibly the formation, of dark matter, and hopefully dark energy.
Euclid will also perform a deeper study of the Universe. Selecting some 100 million galaxies upon which to focus its eye. By carefully measuring the tiny “wiggles” in galaxy clusters, researchers can measure how dark energy has influenced their evolution over the course of their existence.
The Work Begins
Planned for launch by 2020, the mission has nearly 1,000 scientists and engineers from around the world working to build this stunning new instrument.
The joint ESA-NASA project recently announced that 53 researchers from the Jet Propulsion Laboratory, Caltech, and NASA´s Goddard Space Flight Center would be working with their foreign collaborators to bring this observatory to life.
The answers to the nature of the Universe are out there, and the work begins now to begin bringing the darkness to light.