The European Space Agency’s Hera spacecraft launched with a SpaceX Falcon rocket on a two-year journey to study the asteroid Dimorphos, which was deliberately struck by NASA’s Dart mission in 2022. This cosmic crash test demonstrated the potential to deflect a dangerous asteroid threatening Earth.
Hera will closely examine the impact, debris, and any changes to Dimorphos’ orbit and shape, providing valuable data for future planetary defence strategies.
The $400 million mission will reach Dimorphos by 2026, after a gravity boost from Mars, and spend six months orbiting and surveying the asteroid. Two small Cubesats will perform close-up inspections, and Hera may attempt a landing on Didymos, Dimorphos’ larger companion. Scientists hope this investigation will refine methods for deflecting hazardous asteroids in the future.
Belgian involvement
Four researchers from UCLouvain are contributing to the calculations of the trajectory for the European Space Agency’s Hera satellite, which will investigate a binary asteroid system. Jérémy Rekier, a geophysicist and planetary scientist, highlights the challenges of navigating between two asteroids, as it requires accounting for the gravitational influences of both bodies simultaneously. This mission is a first of its kind, getting closer to a binary asteroid system than ever before, which could provide crucial insights into Earth’s formation and future asteroid threats. In the event of an asteroid potentially colliding with Earth, timely trajectory adjustments are necessary to avoid impact.
Additionally, the Royal Observatory of Belgium, in collaboration with a Spanish company, developed GRASS (GRAvimeter for Small Solar system objects), the first instrument to measure the surface gravity of an asteroid. Véronique Dehant, a planetary scientist from the Observatory, explains that understanding an asteroid’s density is crucial for calculating how it will react to impact. GRASS will land on Dimorphos in December 2026 to gather data, a project that has been in preparation for six years.
