Phaethon is just the 11th known asteroid to demonstrate a changing rotational period
The Japan Aerospace Exploration Agency intends to launch its DESTINY+
mission to the near-Earth asteroid Phaethon in 2024, with the aim of
flying by the space rock in 2028, so this “potentially hazardous”
asteroid has been studied intensely in the lead-up to the mission.
Researchers recently made one particularly notable discovery about Phaethon: Its spin is speeding up. The asteroid’s
rotational period is decreasing by 4 milliseconds per year. Even a
small change like this could impact the DESTINY+ observations. Knowing
the specific spin rate allows the team to more accurately predict the
asteroid’s orientation during the spacecraft’s flyby — in turn, that
allows the team to be more specific with their observations.
It’s
rare for an asteroid’s spin to change; Phaethon is just the 11th known
asteroid to show a change in its rotational period, and it’s the largest
of those space rocks, with an average diameter of 3.4 miles (5.4
kilometers). …
