The Japan Aerospace Exploration Agency intends to launch its DESTINY+ mission to a asteroid near-Earth, Phaethon, in 2024, with the goal of flying close to the space rock in 2028, so this asteroid “potentially dangerous” has been intensively studied in the run-up to the mission.
as collected space.comresearchers have made a particularly remarkable discovery about Phaethon: its spin is accelerating. The asteroid’s rotation period is decreasing by 4 milliseconds per year.
Even a small change like this could affect 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 Please be more specific with your observations.
It’s rare for an asteroid’s spin to change; Phaethon is only the 11th known asteroid to show a change in its rotation period, and it is the largest of those space rocks, with an average diameter of 5.4 kilometers.
Using data and observations from 1989 to 2021, Sean Marshall, A planetary scientist at the Arecibo Observatory in Puerto Rico, created a model to determine Phaethon’s shape in preparation for the DESTINY+ mission.
“The shape model predictions did not match the data,” Marshall said in a statement. “The times when the model was brightest were clearly out of sync with the times when Phaethon was observed to be brightest. I realized this could be explained because Phaethon’s rotation period changed slightly andsometime before the 2021 observations, perhaps when it was near perihelion (the point of its orbit closest to the sun) in December 2020.”
Marshall determined that the model that best fit the data included a constant rotational acceleration; in other words, the regular decrease of Phaethon’s rotation period from 4 milliseconds per year.
“This is good news for the DESTINY+ team, as a constant change means that Phaethon’s orientation at the time of the spacecraft’s flyby can be accurately predictedso they will know which regions will be illuminated by the sun,” Marshall said.
Scientists are still learning about Phaethon, and the DESTINY+ mission is sure to reveal more. But we know that even though Phaethon is big enough and close enough to Earth to be labeled as a potentially hazardous asteroidscientists have determined that it poses no immediate threat to our planet.