One-kilometer asteroid 152637 (1997 NC1) passed Earth safely June 27, observed by NASA radar for first time
A roughly one-kilometer-wide asteroid passed Earth safely on June 27, close enough for scientists to bounce radar off it for the first time. NASA tracked 152637 (1997 NC1) with its Goldstone antennas in California, turning a safe flyby into a rare chance to measure its size, shap
A roughly one-kilometer-wide asteroid swept safely past Earth on June 27, and astronomers used the moment to study it with radar for the very first time. The object, catalogued as 152637 (1997 NC1), was originally found by the Near-Earth Asteroid Tracking system on Haleakala in Hawaii. Until this approach, it had never been observed by radar. NASA planned the campaign around its Goldstone Deep Space Communications Complex in California, using one 34-meter antenna as a transmitter and a second as a receiver to catch the echoes. Radar is one of the only techniques that can measure an asteroid's true size, shape, rotation, and orbit directly from the ground, rather than inferring them from a faint point of light. There was never any risk to Earth from this pass. The value was scientific: a kilometer-scale object is large enough that a precise radar profile meaningfully improves how accurately its orbit can be tracked over the long term, which is exactly the kind of groundwork planetary defense depends on.