NASA’s Lucy mission to Jupiter’s fossil asteroids: Everything to know

Lucy flies over a Trojan asteroid in this NASA animation.

NASA’s Goddard Space Flight Center

NASA is embarking on a space archeological mission through the ages. Out in Jupiter’s orbit is a collection of rocks known as the Trojan asteroids – fossils from the earliest era in our solar system. These time capsules are locked in a dance around the sun and may contain the key to unlocking the origin of the giant planets.

Next week, NASA sends the spacecraft Lucy against these ancient raw materials in an ambitious and daring decade-long mission to access the well-preserved history of our solar system.

Perfectly named after the fossil that taught us about the origin of humanity, Lucy’s 12-year journey promises to reveal a cosmic evolutionary record. The spacecraft will have close-ups of a diverse range of Trojan asteroids to help scientists decipher how and why the planets of our solar system came into being.

Right now, we know almost nothing about the properties of these primitive rocks. But we have gathered everything we can to help you prepare for the big launch.

Cue “Lucy in the sky with diamonds.”

How to watch NASA launch the Lucy mission

You can see the lift-off that is currently scheduled for October 16 at 2:34 PT (5:34 ET), online on NASA TV.

Be sure to check back closer to the big day for a livestream on CNET Highlights and at all times across the globe.

And while you wait, let’s dive into why this mission may change the world for astronomers.

What are the Trojan asteroids?

Long before planets came into being, the solar system overflowed with trillions of rocky and icy bodies orbiting a faint sun. Some of these fragments slowly fused together to form larger planets, such as Earth and Mars. But along the way, there was a bunch of liquid rock left over.

Many were swept into the infinite depths of the universe – taking their secrets with them – but there is still a smash in the far reaches of our solar system.

Caught between the gravity of the sun and Jupiter are these primitive pieces of stone that have existed for billions of years. They are known as Jupiter’s Trojan asteroids. NASA aptly refers to them as “time capsules from the birth of our solar system”, and they form two clusters that share an orbit with the gas giant. Over 7,000 have been discovered so far.

“The things that went into growing Jupiter and Saturn are now trapped in these places,” NASA’s planetary scientist and chief scientist at the Lucy mission, Hal Levison, said in the mission statement.

Where does Lucy come in?

Lucy will be the first spacecraft to jump asteroid-jump among seven of the Trojan asteroids, but before going to both the leading and rear swarms, it visits a main-belt asteroid between Mars and Jupiter.

In green you see the leading and rear swarms of Jupiter Trojans. That’s where Lucy’s going.


“We are going to eight never before seen asteroids in 12 years with a single spacecraft,” said Tom Statler, Lucy project scientist at NASA’s headquarters in Washington in a statement. “This is a great opportunity for discovery as we explore the distant past of our solar system.”

NASA notes that “no other space mission in history has been launched to so many different destinations in independent orbits around our sun,” and that “for the first time, Lucy will show us the diversity of the original bodies that built the planets.”

The spacecraft will use traditional chemical propulsion technology that helps maneuver, but to save fuel, it flies past points of interest instead of stepping slowly. However, this is not much of an obstacle because Lucy can still take pictures and collect spectroscopic information while whizzing by.

Mission goals

Armed with a high gain antenna for communication with Earth; high-tech cameras (color as well as black and white); an infrared spectrometer and thermometer, the spacecraft will check several key functions of these asteroids by capturing their physical properties:

Surface geology: This includes things like shape, crater size, crust structure and layering.

Surface color and composition: Tones and colors on the rocks, mineral makeup and regolith properties, such as loose soil composition, are some of these features.

Interiors and bulk properties: Masses, densities, powder carpets around craters and other petty details include this section.

Satellites and rings: A few of the asteroids may have mini-asteroids orbiting them as if they are the center of their own solar system. Some may even have Saturn-like rings made up of super-small rocks or icy bodies.


NASA’s Lucy will explore eight asteroids over a dozen years.

Lockheed Martin

Preparation for start

It’s not easy to be a NASA probe.

Because Lucy will rely on solar energy for the mission, its arrays — large enough to cover a five-story building — had to undergo intense testing to ensure they would not function during space travel. They are so huge because of how far the probe will travel from the sun.


A scientist working on Lucy’s solar panels.

Lockheed Martin

According to NASA, it will take a total of 20 minutes before these crucial solar panels are extended after launch. “Those 20 minutes will determine whether the rest of the 12-year mission will be a success,” Levison said in a statement.

Mars rovers, such as endurance, have shorter ranges of anxious moments during their EDL phase or entry, descent, and landing sequence.

“Mars landers have their seven minute terror, we have this,” Levison remarked.

After several iterations of testing, Donya Douglas-Bradshaw, Lucy project manager from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement that the execution on Earth was “flawless”.

Although the space is a very different arena.

On October 16, Lucy will be transported to the Vehicle Integration Facility at Cape Canaveral Space Force Station and “paired” with the United Launch Alliance Atlas V rocket. That rocket will help Lucy leave Earth’s atmosphere.

Then Lucy will drive away from our home planet to begin the 12-year journey and swing around the solar system, using Earth’s gravity as leverage three times during the journey.

“Launching a spacecraft is almost like sending a kid off to college – you’ve done what they can to get them ready for the next big step on their own,” Levison said.


Lucy stands 4 feet, almost completely assembled in this photo.

Lockheed Martin

What happens when the mission is completed?

After a dozen years, Lucy will stabilize near Earth and then crusade again to the Trojan asteroid belt. It will be the first spacecraft ever to travel all the way to Jupiter and home.

Future humans will face two possibilities: Collect Lucy as an artifact and bring it down to Earth, or let Jupiter eventually throw it into the sun or out of the solar system.

Not to fear. Lucy’s job will be done by then. And maybe our astronomy books will be changed with the unprecedented information it delivers home.

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