Jansky Very Large Array in New Mexico that consists of 28 dishes each 82-foot-wide (25 meters), are the technological standard today. Vast arrays of radio-antennas, such as the Karl G. (Image credit: SKAO) Famous radio telescopesĪs radio waves are the type of electromagnetic radiation with the longest wavelengths, radio telescopes have to be rather large. The Square Kilometer Array's site in Australia will rely on 130,000 Christmas-tree like dipole antennas to listen to radio waves emitted by objects in the most distant universe. Highly magnetized bodies, such as fast-spinning stellar remnants called pulsars are prime targets for radio astronomy as they send out powerful flashes of radio waves as they spin like superfast cosmic lighthouses. They could determine areas with high concentrations of hot young stars, but also study objects obscured by dust, such as black holes that hide in galactic centers. "But ionized gas can emit radio waves as well."īy tracing the structure of radio wave-emitting clouds, astronomers were able to map out the entire structure of our galaxy, the Milky Way, as well as other nearby galaxies. "Typically, when you detect radio waves, you're looking at electrons moving through a magnetic field," Wibisono said. Systematic exploration of the radio universe began soon thereafter.Īstronomers have discovered since that radio waves are emitted by spinning electrons and emanate from all sorts of environments that have the ability to make those electrons spin, Affelia Wibisono, an astronomer at the Royal Observatory Greenwich in the U.K., told.
Jansky found that while some of this noise was coming from sources on Earth, such as nearby thunderstorms, there was a type of signal, constantly picked up by his experimental antennas, that appeared to be coming from what we know today is the center of our Milky Way galaxy, the region where the black hole Sagittarius A* resides. In 1933, a young American radio engineer Karl Jansky, an employee of the famous telephone company Bell Laboratories, was tasked to search for sources of unexplained hiss that sometimes interfered with transmissions of radio messages across the Atlantic Ocean. The discovery that radio waves from bodies in the universe lash our planet was made completely by accident. Radio astronomy studies cosmic radiation with the longest wavelengths (from less than 0.4 inches to several miles, or 1 centimeter to several kilometers) and was the first kind of astronomy developed that relies on wavelengths other than optical light. (Image credit: NASA) What do radio waves teach us about the universe?
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