Lucy spacecraft launched today to Jupiter’s Trojans

Lucy spacecraft: Yellow arc cuts across night sky, brightening it.
View at EarthSky Community Photos. | Greg Diesel Walck in Ormond Beach, Florida, captured this photo of the launch of the Lucy spacecraft on October 16, 2021. Thank you, Greg!

Lucy spacecraft launched Saturday

The Lucy spacecraft – named for a famous fossilized skeleton found in 1974 in Africa – launched from Cape Canaveral, Florida, on Saturday, October 16, 2021, beginning a 12-year journey. With the help of three gravity assists from Earth, Lucy will travel almost 4 billion miles (6 billion km) in 12 years, exploring one asteroid in the main asteroid belt and seven of Jupiter’s Trojan asteroids. The Trojans move in Jupiter’s orbit around the sun and have never been explored before. And scientists view them as fossils that are left over from the formation of the solar system.

Our fossilized ancestor called Lucy dates to some 3.2 million years ago. The skeleton of the fossil Lucy provided unique insight into human evolution. Likewise, the Lucy space mission will hopefully provide insight into our solar system’s evolution. Astronomer Hal Levison of the Southwest Research Institute (SwRI) in Boulder, Colorado, leads the Lucy mission. He spoke about Lucy’s journey to Jupiter’s Trojans and about how the mission got its name:

The Trojan asteroids are leftovers from the early days of our solar system, effectively fossils of the planet formation process. They hold vital clues to deciphering the history of our solar system. The Lucy spacecraft, like the human ancestor fossil for which it is named, will revolutionize the understanding of our origins.

Lucy’s 4-billion-mile journey will take it out to the orbit of Jupiter and the realm of Trojan asteroids, then back in toward Earth for gravity assists three times. This will be the first time a spacecraft has ever returned to Earth’s vicinity from the outer solar system.

Diagram showing the inner solar system, asteroid belt and Jupiter and its orbit, with locations of Trojan asteroids indicated.
The white “donut” represents the asteroid belt. Astronomers use the name Trojans for all the asteroids collected at Jupiter’s 2 stable Lagrange points. The asteroids move in Jupiter’s orbit, 60 degrees ahead of and behind the giant planet. By convention, asteroids orbiting in front of Jupiter are named for the Greek heroes of the Trojan War. And asteroids trailing behind Jupiter are named for the Trojan heroes. Image via Wikimedia Commons.

Target: Trojan asteroids

Trojan asteroids are a unique group of rocky bodies. Left over from the formation of the solar system, they orbit the sun on either side of Jupiter. No spacecraft has previously explored this collection of solar system fossils. Jupiter’s gravity traps these asteroids in two swarms in its orbit, with some ahead of the planet and some trailing behind.

Deputy principal investigator Cathy Olkin said:

Lucy’s ability to fly by so many targets means that we will not only get the first up-close look at this unexplored population, but we will also be able to study why these asteroids appear so different. The mission will provide an unparalleled glimpse into the formation of our solar system, helping us understand the evolution of the planetary system as a whole.

Bald man with big white beard and woman with short blonde hair, both wearing black.
Hal Levison, principal investigator, and Cathy Olkin, deputy principal investigator, lead the Lucy mission. Image via SwRI.

Launching the Lucy spacecraft

Team members for the Lucy mission have spent weeks at NASA’s Kennedy Space Center prepping and practicing for the launch. Levison said the spacecraft is ready, elaborating:

Launching a spacecraft is almost like sending a child off to college. You’ve done what you can to get them ready for that next big step on their own. Lucy is ready to fly.

Lucy launched on an Atlas V rocket on its first attempt, at 5:34 a.m. EDT (09:34 UTC) on Saturday, October 16, 2021. The team checked in at 1 a.m. (05:00 UTC) to begin their run-through of the full launch countdown procedures.

Lucy spacecraft with two large solar panels in front of large rocky object.
Artist’s concept showing the Lucy spacecraft exploring a Trojan asteroid. Image via SwRI.

Bottom line: The Lucy spacecraft successfully launched early Saturday morning, October 16, 2021 on an Atlas V rocket. It will journey to Jupiter’s Trojan asteroids, fossils of the solar system’s formation that lie along Jupiter’s orbit.

Via Southwest Research Institute

Read more about the Lucy mission

October 16, 2021

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