Astronomers say they've measured dark matter for first time

William Atkins
Friday, 08 January 2010 21:07

Science - Space

U.S. astronomers have announced that they have made the first definitive measurement of dark matter. They describe the shape indirectly observed as similar to a "squashed … cosmic beach ball."


Dr. David R. Law, of the University of California, Los Angeles (UCLA), announced the team’s finding on Wednesday, January 6, 2010, at the 215th meeting of the American Astronomical Society (AAS215), which was held from January 3-7, 2010, in Washington, D.C.

Law’s two other collaborators in this important measurement are Dr. Steven Majewski (of the University of Virginia, Charlottesville, Virginia) and Dr. Kathryn Johnston (of Columbia University, New York City).

This discovery by these three researchers is being called the “first definitive measure” of dark matter.

Dark matter is a type of matter that makes up possibly one-fourth of all mass of the observable universe--who knows, maybe the majority of mass in the universe is made up of dark matter and dark energy).

However, it is not directly detectable because it does not interact with electromagnetic (EM) radiation (such as visible light, x-rays, gamma rays, and other such types of EM radiation).

That is, we can’t detect it from the EM radiation that it emits.

Fortunately, astronomers can indirectly “see” dark matter through the gravitational effects it has on visible matter (that is, it has mass so its gravity can affect other massive bodies around it).

Page two continues.