Ramses: ESA’s Apophis Asteroid Mission
ESA’s Space Safety program has obtained permission to begin preparatory work for its next planetary defense mission – the Rapid Apophis Mission for Space Safety (Ramses). Ramses will rendezvous with the asteroid 99942 Apophis and accompany it through its exceptionally close flyby of Earth in 2029. This rare event, where an asteroid of this size comes so close to Earth, occurs only once every 5000 to 10,000 years.
Roughly 375 meters across (about the size of a cruise liner), Apophis will pass within 32,000 km of Earth’s surface on April 13, 2029. For a brief period, it will be visible to the naked eye for around two billion people in parts of Europe, Africa, and Asia. While Apophis will safely miss Earth, with no chance of impact for at least the next 100 years, the flyby presents a unique opportunity for science and planetary defense.
Ramses needs to launch in April 2028 to arrive at Apophis in February 2029, two months before the close approach. Using its suite of scientific instruments, the spacecraft will conduct a thorough survey of the asteroid’s characteristics before and after the Earth flyby. By analyzing how Apophis changes during this event, researchers will gain valuable insights into:
- Asteroid composition and interior structure
- Cohesion, mass, density, and porosity
- Responses to external forces like Earth’s gravity
This data very important for assessing how best to deflect a potentially hazardous asteroid on a collision course with Earth. As time capsules from the early Solar System, asteroid observations will also yield new scientific understanding of planetary formation and evolution.
The primary observational objectives of the Ramses mission revolve around studying the effects of Earth’s gravitational forces on the asteroid Apophis during its close flyby in April 2029. By conducting detailed analyses before and after the flyby, researchers aim to gain unprecedented insights into the physical characteristics and behavior of asteroids subjected to such intense tidal forces.
One critical aspect is to monitor the changes in Apophis’ shape and surface features. Earth’s gravity is expected to trigger landslides, quakes, and other disturbances that could reveal fresh material from beneath the asteroid’s surface. Ramses’ instruments will closely observe these surface alterations, providing valuable data on the cohesion and structural integrity of the asteroid’s regolith and internal composition.
Additionally, researchers will meticulously track any shifts in Apophis’ orbit, rotation, and orientation caused by the flyby. These measurements will help refine our understanding of how external forces can alter an asteroid’s trajectory and spin state, which especially important for developing strategies to deflect potentially hazardous objects in the future.
Furthermore, the mission will gather data on the asteroid’s mass, density, and porosity, which are essential parameters for accurately modeling the response of such bodies to various deflection techniques. By combining these observations with the surface and structural analyses, scientists hope to gain a comprehensive picture of the physical properties that govern an asteroid’s behavior under extreme gravitational stresses.
Ultimately, the unique observational opportunities presented by the Apophis flyby will not only enhance our planetary defense capabilities but also shed light on the formation and evolution of asteroids, providing invaluable insights into the early history of our Solar System.
