source : www.sci.news
On November 1, NASA’s Lucy spacecraft flew past not only its first asteroid – the small main-belt asteroid (152830) Dinkinesh – but also the first two. The first images returned by Lucy show that Dinkinesh is actually a binary asteroid.
Dinkinesh, also known as VD57 from 1999, is a stony asteroid in the main asteroid belt between Mars and Jupiter.
It was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on November 4, 1999.
It rotates with a period of 52.67 hours and varies in brightness with a light curve amplitude of 0.39 magnitudes.
“Dinkinesh really lived up to his name; this is great,” said lead researcher Dr. Hal Levison of Lucy, a researcher at the Southwest Research Institute, referring to the meaning of Dinkinesh (“you are wonderful”) in Amharic.
“When Lucy was originally selected to fly, we planned to fly past seven asteroids. With the addition of Dinkinesh, two Trojan moons and now this satellite, we have increased the number to eleven.”
Based on a preliminary analysis of the first available images, Dr. Levison and colleagues that the larger body is about 790 m (0.5 mi) at its widest, while the smaller one is about 220 m (0.15 mi) in size.
This flight past Dinkinesh served primarily as an in-flight test of the spacecraft, with a specific focus on testing the systems that allow Lucy to autonomously track an asteroid as it flies past at a speed of 16,000 km per hour (10,000 mph), also called terminal tracking. system.
“We have seen many asteroids up close, and you might think there is little left to discover and surprise us. Well, that’s clearly wrong,” said Lucy deputy chief investigator Dr. Simone Marchi, also from the Southwest Research Institute.
“Dinkinesh and its enigmatic moon differ in some interesting ways from the similarly large near-Earth asteroids observed by spacecraft such as OSIRIS-REx and DART.”
“This is an amazing set of images,” said Tom Kennedy, Lucy’s guidance and navigation engineer at Lockheed Martin.
“They indicate that the terminal tracking system worked as intended, even when the universe presented us with a more difficult target than we expected.”
“It’s one thing to simulate, test and practice. It’s another thing to actually see it happen.”
Although this encounter was conducted as a technical test, the Lucy scientists are excitedly studying the data to understand the nature of small asteroids.
“It was incredibly exciting to share the anticipation of viewing the first images with the team, as well as the lively discussion about the geology of these two remarkably small but fascinatingly intriguing targets,” said Dr. Silvia Protopa, researcher at Southwest Research Institute. .
“I am eagerly looking forward to unraveling the color variations in this binary system.”
“We knew this would be the smallest main belt asteroid ever seen up close,” said Lucy project scientist Dr. Keith Noll, researcher at NASA’s Goddard Space Flight Center.
“The fact that there are two makes it even more exciting. In some ways these asteroids are similar to the near-Earth asteroid binaries Didymos and Dimorphos that DART saw, but there are some really interesting differences that we will explore.”
The Lucy researchers will continue to downlink the remainder of the spacecraft’s encounter data over the next week.
They will use the data to evaluate Lucy’s behavior during the encounter and prepare for the next close-up of an asteroid, the main belt asteroid Donaldjohanson, in 2025.
Lucy will then be well prepared to observe the mission’s main targets, the Jupiter Trojan asteroids, from 2027 onwards.
source : www.sci.news