Overview
- A Science Advances study measures a 0.15‑second reduction in the Didymos–Dimorphos system’s 770‑day solar orbit, corresponding to a speed change of about 11.7 micrometers per second.
- Researchers say this is the first confirmed instance of a human‑made spacecraft measurably altering the solar orbit of a natural object.
- The finding relied on exceptionally precise observations, including 22 stellar occultations recorded by volunteer astronomers from October 2022 to March 2025, combined with radar and other ground‑based data.
- Ejecta from the 2022 DART impact roughly doubled the effective impulse (momentum enhancement factor ≈ 2), building on earlier results that Dimorphos’s 12‑hour orbit around Didymos shortened by 33 minutes.
- ESA’s Hera spacecraft is due to arrive later in 2026 for in‑situ measurements, as agencies emphasize the need for earlier detection via NASA’s NEO Surveyor and note there are no DART‑like spacecraft on standby.