The near-Earth asteroidResponsible for the extraordinary annual Geminids meteor showerAstonished to be caught doing something totally unexpected.
Scientists study the changing light of 3200 PhaethonThe rocky body appears to be spinning faster on its axis than previously thought, with a reduction of around 4 milliseconds each year. Although it might seem like a lot to you, asteroid spins rarely change.
Figuring out why Phaethon is behaving this way could give us new insight into a class of asteroids considered “potentially hazardous” – skimming past Earth as they orbit the Sun.
Phaethon poses no threat to Earth at the moment, but its size of 5.8 kilometers (3.6 miles) would be enough to cause significant pain if it did hit. Asteroid’s trajectory brings it within striking distance of Earth, but enough change in its orbit over 524 days could lead to us reconsidering our concerns.
It is also a strangeball. The orbit of the asteroid is very similar to that of a comet. It also has a dusty trail and it is one of two asteroids that produces this material. Meteor showersThese come mostly from comets.
It appears to be free of ice, which is a characteristic that makes it different from a comet. Scientists call it a “”Rock comet“.
It’s amazing! blue. Most asteroids have a reddish or gray color.
Phaethon’s unique characteristics make it the ideal target for a future lander mission. DESTINY+The Japanese Space Agency led the Demonstration and Experiment of Space Technology to INterplanetary VoYage with Phaethon FLyby and Data Science. Scientists have been studying the rock in order to better plan how they can rendezvous.
Phaethon’s brightness changes with its rotation, so we have been able characterize its time of rotation over time, narrowing down it to 3.6 hours. We need exact data to land a probe on the thing. So planetary scientist Sean Marshall from Arecibo Observatory in Puerto Rico was trying to refine Phaethon’s size, shape and rotation when he noticed something wrong.
He presented The findings of his teamLast week, at the American Astronomical Society’s 54th Annual Meeting of Division for Planetary Sciences.
“The predictions of the shape model were not consistent with the data.” Marshall.
“The times that the model was shining brightest were clearly not in sync with those when Phaethon was actually visible to be the brightest. I realized that Phaethon could have its rotation period change slightly in the time prior to 2021 observations. This may be due to comet-like activity at December 2020, when it was very close to perihelion.
The full dataset covering the period 1989-2021 revealed that there was a steady, gradual acceleration. This means that 4 milliseconds per year of rotation time is being lost. Although the difference isn’t significant year-on-year it has become more noticeable over the years.
Researchers noticed a discrepancy between the rotational periods. Returned in 2016When they discovered that their 1989 data was out-of-sync, the researchers were shocked. The researchers didn’t have enough information at the time to explain the difference. This discrepancy seems to have been resolved.
This makes Phaethon, one of only 11 asteroids that have accelerated rotations out of thousands of asteroids that have been characterized. This could be the result of mass-loss. OutgassingComets produce a spin-up effectA study done last year by Phaethon suggested that Phaethon could be a potential candidate. Outgas sodium.
It’s also possible that a small Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect Exceptions may apply. This happens when the heat from a star affects the spin rate of small bodies, such as an asteroid.
There will be more work to determine what is happening with Phaethon. However, knowing that the spin rate and rate at which it is changing is an amazing finding.
“This is great news for the DESTINY+ group.” Marshall.
“A steady change means Phaethon can predict accurately its orientation at the time the spacecraft passes by, so they’ll know which regions will receive illumination from the Sun.”
The team Their findings were presentedat the American Astronomical Society’s 54th Anniversary Meeting of the Division for Planetary Sciences.
