While NASA is making efforts to test asteroid deflection techniques, another object on the potential danger list has unexpectedly changed its course, leaving scientists uncertain whether this is good or bad.
During preparations for the DESTINY+ mission (scheduled for launch in 2024 to approach the asteroid Phaethon), the Japan Aerospace Exploration Agency (JAXA) made a surprising discovery: their target has.. “fled.”
According to Space, the asteroid Phaethon, discovered by NASA, has been shortening its orbit by 4 milliseconds each year. While this may seem trivial, such changes—especially continuous ones with an inexplicable acceleration—could significantly impact predictions about the object’s trajectory.
The asteroid Phaethon observed through various observations – (Photo: Arecibo/NASA/NSF)
For now, knowing the exact position of the asteroid will help scientists guide the DESTINY+ spacecraft to the correct location, which is expected to occur in 2028.
Additionally, this will be a crucial parameter for predicting the asteroid’s orbit, which must be continuously monitored, as Phaethon is classified as a “potentially hazardous” space object for Earth.
It is very rare for an asteroid’s orbit to change. Phaethon is the 11th recorded asteroid to exhibit this unusual behavior and is the largest of the eleven, with an average diameter of 5.4 km.
Using observational data spanning over three decades—from 1989 to 2021—planetary scientist Sean Marshall from the Arecibo Observatory in Puerto Rico, who collaborates with JAXA, created a model of Phaethon in preparation for the DESTINY+ mission and discovered this anomaly.
“The predictions from the shape model did not match the data. The times when the model was brightest did not synchronize with the times when Phaethon was brightest. I realized this was due to a slight change in Phaethon’s rotation period,” Dr. Marshall stated.
According to him, the changes may have occurred when the asteroid reached its perihelion (the point closest to the Sun), acting like a comet, emitting a brilliant halo and losing quite a bit of material.
This discovery was recently reported at the 54th Annual Meeting of the Planetary Science Division of the American Astronomical Society, coinciding shockingly with a recent successful test by NASA: the DART mission to deflect an asteroid.
While DART was designed to prepare for deflecting an object whose orbit could lead it directly toward Earth, Phaethon is unexpectedly changing its course on its own.
The good news is that despite the changes, calculations indicate that it currently poses no threat to our planet. However, scientists will certainly need to keep a close watch on it in the future.
The asteroid Phaethon, officially designated as 3200 Phaethon, is not unfamiliar to Earth dwellers. Because it behaves like a comet, it produces a trail of dust and debris that inadvertently intersects with Earth’s orbit.
“The ghost” of Phaethon that humans often see is the beautiful Geminids meteor shower – (Photo: INTERNATIONAL METEOR ORGANIZATION)
You cannot see the asteroid itself with the naked eye, but its debris can be observed brightly in mid-December each year: this is the Geminids meteor shower, one of the largest meteor showers of the year, with a peak of up to 150 meteors per hour.
