Calculating an asteroid's mass remains one of the hardest tasks in planetary science, yet it is critical for assessing impact risk and resource potential. Traditional methods rely on optical sensing and density estimates from spectral profiles, which introduce significant uncertainty.
A newly published paper suggests a novel approach using the Laser Interferometer Space Antenna (LISA), a flagship space mission, to achieve highly accurate mass calculations for nearby asteroids. The proposal requires no changes to LISA's existing hardware, leveraging its precision interferometry to detect subtle gravitational effects.
LISA is designed to observe gravitational waves from space, but its sensitivity to minute disturbances could be repurposed for asteroid mass measurements. The technique would track how an asteroid's gravity subtly alters the paths of LISA's test masses, effectively weighing the object from millions of kilometers away.
This method could revolutionize asteroid characterization without additional mission costs. It offers a pathway to refine impact hazard assessments and better quantify resources on near-Earth objects, though it depends on LISA's successful deployment and operational calibration.
Critics note that LISA's primary mission remains gravitational wave detection, and any secondary use must not interfere with its core science. The proposal also relies on favorable asteroid flybys during the spacecraft's operational lifetime, which may limit its application.