(NASA's Goddard Space Flight Center https://go.nasa.gov/3pwBwAG)
A group of astronomers from the Southwest Research Institute (SwRI) studied the Trojan asteroid Jupiter, Polymele and found a surprise.
This was one of the targets for NASA’s Lucy mission.
They discovered a satellite with a diameter of 5 kilometers from the asteroid, which is located at a distance of about 200 kilometers from the main body.
Lucy was launched in October last year and its mission is to study several Jupiter Trojan asteroids located near the Lagrange points L4 and L5 in the Sun-Jupiter system
The spacecraft was also going to observe one Main Belt asteroid from a flyby trajectory.
Equipped with two cameras and two spectrometers, the spacecraft will for the first time:
- obtain detailed images of the surface of the Trojan asteroids
- assess their composition
- assess their internal structure
Thus, planetary scientists will be able to learn more about the processes that took place in the early solar system.
THE DISCOVERY
Initially, there were six Trojans among the targets of the station - four single and two forming a pair.
However, in 2020, the Hubble telescope discovered a small satellite near the asteroid (3548) Eurybates, which increased the total number of targets to eight.
Now, a team of astronomers led by Marc Buie from the SwRI announced that they discovered a satellite of the Trojan asteroid (15094) Polymele, with a maximum width of 27 kilometers.
This brings the total number of targets for the station to nine, which is a record.
The discovery was made thanks to an observational campaign conducted on March 27, 2020, in which 26 teams of both professional and amateur astronomers participated.
The observers tracked the occultation of the background star by the asteroid, allowing them to estimate the size and shape of Polymele with great accuracy.
Similar observations were made earlier: in 2017 it was possible to suspect the duality of the Kuiper Belt object Arrokoth, to which the New Horizons station was then heading.
At the time of observation, Polymele was at a distance of 770 million kilometers from Earth.
Analysis of the collected data showed that the Polymele satellite has a diameter of about 5 kilometers and is located at a distance of about 200 kilometers from the main body.
The object will not be able to receive an official designation until its orbit is precisely determined.
However, the satellite is not available to ground or near-Earth telescopes, as it is close to Polymele.
Therefore, scientists will wait for new events of occultation of stars by an asteroid.
Source:
Upvoted! Thank you for supporting witness @jswit.
Downvoting a post can decrease pending rewards and make it less visible. Common reasons:
Submit