help

What Causes the Light and Dark Areas on Radar Images of Asteroid 2015 TB145?

-- | November 5, 2015

Question: Just saw the stunning images of asteroid 2015 TB145. These are images obtained by illuminating the asteroid with microwaves from a source nearly the same direction as the receiving antenna. Why does the asteroid appear to be illuminated from the side, instead of directly from the front? — Steve

Answer: The light and dark areas on radar images of objects such as the asteroid 2015 TB145 are due to high and low reflectance of the radar signal off of the asteroid’s surface. For example, the brighter areas are places where the radar signal reflectance is higher than it is in the darker areas. This higher or lower reflectance can be due to ridges or other changes in the topography of the asteroid, or can also be due to changes in the roughness of the asteroid’s surface.

Jeff Mangum

Facebook
Pinterest
Twitter
Linkedin

The National Radio Astronomy Observatory is a facility of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
	Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.
	The U.S. National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."
	AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.