The Indian spacecraft, which is small at about half the size of a smart car, was found using existing interplanetary radar technology.
"Although the interplanetary radar has been used to observe small asteroids several million miles from Earth, researchers were not certain that an object of this smaller size as far away as the moon could be detected, even with the world's most powerful radars," NASA said in its report. "Chandrayaan-1 proved the perfect target for demonstrating the capability of this technique."
Scientists said the discovery could be pivotal to planning future moon missions.
The large radar antennas at NASA's Goldstone Deep Space Communications Complex in California, the Arecibo Observatory in Puerto Rico and the Green Bank Telescope in West Virginia working in tandem might be used to detect and track "even small spacecraft in lunar orbit," scientists said.
Meanwhile, NASA researchers said, "Ground-based radars could possibly play a part in future robotic and human missions to the moon, both for a collisional hazard assessment tool and as a safety mechanism for spacecraft that encounter navigation or communication issues."