New telescope data boosts asteroid mission

Astronomers have used observatories around the world to study asteroid 1998 KY26, revealing it to be almost three times smaller and spinning much faster than previously thought.

Asteroid 1998 KY26

An international team of researchers used observatories around the world to study asteroid 1998 KY26 to support the preparation of the future Hayabusa2 mission. Because the asteroid is very small and, hence, very faint, studying it required waiting for a close encounter with Earth and using large telescopes, like the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile’s Atacama Desert. 

Researchers from the Institute for Astronomy were involved in determining the size of the asteroid using ESO’s VLT observations, models gathered from the international team, and by reprocessing archival radar data. The Edinburgh contribution was crucial because, while other techniques could constrain how fast the object rotates and what its composition is, adding the radar data allowed the team to determine the size with meter-level precision.

Hayabusa2 spacecraft mission

Asteroid 1998 KY26 is set to be the final target asteroid for the Japanese Aerospace eXploration Agency (JAXA)'s Hayabusa2 spacecraft.

In its original mission, Hayabusa2 explored the 900-metre-diameter asteroid 162173 Ryugu in 2018, returning asteroid samples to Earth in 2020.

With fuel remaining, the spacecraft was sent on an extended mission until 2031, when it’s set to encounter 1998 KY26 which measures just 11 metres in diameter - the first time a space mission encounters such a tiny asteroid.

Outcomes

With the ability to characterise such small objects, astronomers can identify further such objects in the future. The team believes this could have impact on future near-Earth asteroid exploration or even asteroid mining.