Over the next few years, there are plans to build 1.4 meter telescopes similar to the instrument being installed this month atop South Baldy Mountain in New Mexico. Despite the billion-dollar telescopes grabbing headlines, these smaller lensed telescopes will surpass any other optical telescope in its eye for detail, writes Adam Mann for Science.
The $200 million Magdalena Ridge Observatory Interferometer (MROI) is set to be completed by 2025, and will have the equivalent resolution of a large telescope 347 meters across. Combining light from the spread-out telescopes will allow the instrument to make out small structures on stellar surfaces, image dust around newborn stars, and view supermassive black holes at the center of some galaxies. It will even be able to spy on spy satellites making out details as small as a centimeter across on satellites 36,000 kilometers above Earth. The U.S. Air Force is funding MROI to take advantage of these capabilities. As Michelle Creech-Eakman, an astronomer at the New Mexico Institute of Mining and Technology, explains it, “they want to know: Did the boom break or did some part of the photovoltaic panels collapse?”
Still, MROI, and optical interferometry in general, has made slow progress. Because the short wavelengths of visible light cannot yet be digitized by any electrical system, the light must be merged in real time, with nanometer precision. “Interferometry is still something of a dirty word around NASA,” says Gerard van Belle, chief scientist at the Navy Precision Optical Interferometer. But, support is still there for this instrument. Once complete, MROI’s telescopes will be more widely separated than any other interferometer, enabling its superior resolution.