Flyby of Earth: Japan to take part in ESA asteroid mission to Apophis
In four years, the 400-metre asteroid Apophis will come exceptionally close to Earth. The ESA wants to accompany it with a probe, and Japan is interested.
Artist's impression of the asteroid Apophis with the Ramses probe
(Image: ESA-Science Office)
The Japanese space agency wants to participate in a European space mission in which a probe is to accompany the asteroid Apophis on its extraordinarily close flyby of Earth. ESA has now made this public and explained that JAXA wants to provide the solar collectors, an infrared camera and the launch facility for the mission called Ramses (Rapid Apophis Mission for Space Safety). A corresponding request has been made to the Japanese government. However, it has still not been decided whether Ramses will actually be realized; the ESA Council of Ministers is not due to make a decision until November. However, due to the time pressure, preparatory work has already begun.
A unique opportunity for science
Apophis was discovered in 2004 and named after one of the most important antagonists in the then current television series Stargate SG-1. Because the probability of an impact on Earth in 2029 was initially determined to be as high as 2.7 percent, the celestial body attracted a lot of attention. Thanks to additional data, this impact was ruled out, which was later also confirmed for the flybys in 2036 and 2069. The predictions were made more difficult by the fact that it was not possible to determine precisely enough to what extent Apophis would be deflected by its approaches to Earth. The asteroid has a diameter of 375 meters, so a collision would have catastrophic consequences.
Now that a nearby danger to Earth has been ruled out, scientific interest in Apophis has continued to grow. In view of the extraordinarily close flyby in just four years' time, this is an opportunity that research only gets once every millennium, writes the ESA. That is why Ramses is to be sent to accompany it as it speeds past the Earth's surface at a distance of just 32,000 km. As the probe must be launched by 2028 at the latest, preparations have already begun, even if final approval for the mission is still pending. Before, during and after its approach to Earth, Ramses will observe how the asteroid changes under Earth's gravitational pull.
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However, if Ramses is approved, it would not be the only space probe to study Apophis directly. With Osiris-Apex, a rededicated NASA probe is also on its way to Apophis. As Osiris-Rex, it visited the asteroid Bennu and brought a rock sample from there to Earth. It then set course for Apophis and, after approaching the sun, worked even better than before. Due to its orbit, however, it will only arrive there about a month after Apophis has passed Earth, so it can only explore it retrospectively. Ramses is intended to close the gap and the ESA is pleased that Japan is interested in participating.
(mho)
