Lucy Passes by its First Target: The Dinkinesh Asteroid

As previously announced by NASA on January 25, 2023, well after the launch of Lucy, the spacecraft’s first encounter with an asteroid happened on November 1, 2023, reaching the closest distance of 427 Km at 16:54 UTC. The purpose of this flyby was to test the Terminal Tracking System‘s engineering capabilities, which is the probe’s innovative asteroid-tracking navigation system. The collected information will help to improve the accuracy of the procedures for the next rocky rendezvous.

Hello Lucy! The spacecraft phoned home and is healthy. Now, the engineers will command Lucy to send science data from the Dinkinesh encounter to Earth. This data downlink will take several days. Thanks for following along today and stay tuned!https://t.co/sFLJS7nRJz pic.twitter.com/P7XpcM4Ks8

— NASA Solar System (@NASASolarSystem) November 1, 2023

Important updates were published by NASA the following day.*

152830 Dinkinesh, a small asteroid with a meaningful name

The original mission plan included visits to nine asteroids, one out of the main belt, and eight of Jupiter’s trojans, the principal scientific targets. While looking for potential additional targets, scientists found that a small rocky body, 1999 VD57, would have passed at only 65.000 Km. In addition, Lucy could have shortened the minimum distance to a few hundred kilometers, adding some small maneuvers to the flight plan.

On January 24, 2023, Lucy’s team added a new target to the original tour, giving it the new name 152830 Dinkinesh, the Ethiopian name for the human-ancestor fossil, also known as Lucy.

As a secondary goal, the flyby of Dinkinesh will improve our knowledge of the S-type asteroids of the main belt and their relationship with the Near Earth Asteroids similar in dimension, type, and shape.

Lucy’s mission, the best is yet to come

Launched two years ago, in October 2021, from Cape Canaveral aboard an Atlas V rocket, the vehicle hasn’t had a flawless flight so far. An issue with one of the two solar arrays held the operations team and all mission supporters in suspense.

After several deployment attempts, the solar array is currently 98% unfurled and it is producing the nominal level of energy. Its structural strength was tested one year ago, during last Earth’s flyby.

Next in Lucy’s tour is another Earth gravity assist in 2024, heading then to another main belt asteroid, 52246 Donaldjohanson, in 2025. This second target, named after the discoverer of the Lucy hominin fossil, will allow the spacecraft operations team to make additional tests of the new navigation system.

In 2027, the probe will reach the first of the eight planned Jupiter Trojan asteroids, 3548 Eurybates, finally unleashing the full capabilities of her scientific instruments.

For more details, please refer to Space Voyaging insight dedicated to the mission: NASA’s Lucy: voyage to the Trojan asteroids.

First images, first surprise, first scientific results

*UPDATE November 2: The first images from Lucy arrived just after the publication of the first version of this article. They showed the first new and unpredicted scientific discovery about Dinkinesh: it is not a single rocky body but a binary pair.

This is why we explore. Turns out that asteroid Dinkinesh is… asteroids Dinkinesh? During the #LucyMission’s first asteroid flyby on Nov. 1, we discovered that the main belt asteroid is a party of two, or binary pair! https://t.co/3aYWLvWmOw pic.twitter.com/IX2ZHHtRdK

— NASA Solar System (@NASASolarSystem) November 2, 2023

“The fact that it is two makes it even more exciting. In some ways, these asteroids look similar to the near-Earth asteroid binary Didymos and Dimorphos that DART saw, but there are some really interesting differences that we will be investigating.”

— Keith Noll, Lucy project scientist

Given these premises, the Lucy Mission will surely reveal many more unexpected discoveries during the next nine fly-bys.