Why is NASA’s Lucy space shuttle on an important voyage?

The National Aeronautics and Space Administration (NASA), US, launched a spacecraft called Lucy on October 16, 2021, on a 12-year voyage. Lucy would be flying past hurtling asteroids circling the planet Jupiter. To make it sound scarier, these asteroids are called Trojans in memory of ancient warriors, and no spaceship has ever visited them. But there’s more to this mission than just the adventure of visiting a dangerous corner of the solar system.  

What are Jupiter’s Trojan asteroids? 
The Trojans are a large group of asteroids that share the Jupiter’s orbit around the Sun, hurtling through space like massive rocky missiles. Lucy will fly by 8 asteroids - 7 Trojans and a main-belt asteroid – and this will take over 12 years. The Trojans are trapped near Jupiter’s Lagrange (L) points, which are gravitationally stable locations, i.e. a space where the gravity from the Sun and Jupiter cancel each other out. This means the orbits are stable and the Trojans have remained trapped in this space from the time they have been created. Till 2020, more than 7,000 Jupiter Trojan asteroids had been discovered.  

Why are the Trojan asteroids important?  
Scientists believe the Trojan asteroids around Jupiter are remnants from the creation of the solar system, scattered and later captured in Jupiter’s orbit. This means these asteroids have remained relatively unblemished for more than four billion years, like time capsules. Even after all these years, these asteroids may contain carbon, water and other compounds necessary for life. They may give us a glimpse into the physical environment that existed when the planets formed, and clues on the conditions that nurtured their formation. Astronomers think this may help us learn more about the origins and evolution of the solar system over 4 billion years ago, so they are understandably excited.   

Why the space craft is called Lucy? 
There is a group of ancient fossils called the Lucy hominin fossils. Since scientists look upon the Trojan asteroids as fossils from the era of planet formation, they chose the name Lucy. Another inspiration was the 1967 Beatles song Lucy in the Sky with Diamonds. Besides, the spacecraft carries a disc made of lab-grown diamonds needed to run some of its instruments.