Our cosmos is awash with radio waves, originating from fierce jets blasting out of distant black holes, blinking dead stars closer to home, and many other exotic objects. To observe radio waves—which possess wavelengths hundreds of thousands of times longer than visible light—astronomers use two types of telescopes: huge single dishes, such as the giant FAST (Five-hundred-meter Aperture Spherical Telescope) in China, and arrays of many dishes, such as the National Radio Astronomy Observatory Very Large Array in New Mexico, whose sprawling 27 dishes were famously featured in the movie Contact.
While the giant single dishes are very sensitive, which means they excel at detecting faint radio waves from across the cosmos, arrays of many dishes can take the sharpest images.
Now, researchers at Caltech are getting ready to build a radio telescope that has both exquisite sensitivity and the ability to take crisp pictures. The Caltech-led Deep Synoptic Array (DSA) recently completed its final design review with Schmidt Sciences, which announced in January that it is funding the project.
The milestone paves the way for construction to begin. Planned for a remote valley in Nevada, the DSA will consist of 1,650 radio dishes, each slightly more than 6 meters in diameter—by far the most dishes to make up a radio array. The array will span an area of about 20 x 16 kilometers. The DSA team plans to build the telescope by 2029, with science operations commencing soon after.