The following is a guest post by Brett Zongker, chief of media relations at the Library of Congress.
In the moments before NASA’s Europa Clipper was set to launch Oct. 14 from the legendary Kennedy Space Center, everything got quiet. All eyes were fixed on a towering SpaceX Falcon Heavy rocket that would carry NASA’s largest spacecraft ever designed for a planetary mission on a 1.8-billion-mile journey.
The mission to explore Jupiter’s moon Europa was in the making for decades and imagined for far longer. Galileo first discovered Europa through a homemade telescope in 1610. Now, scientists believe Europa is another water world covered with an icy crust and may hold the ingredients for life.
The launch had been delayed four days due to Hurricane Milton, whose eye passed directly over the Kennedy Space Center near Cape Canaveral, Florida—a reminder that we, too, are on a planet. Many wondered: Would something go wrong at the last moment? Were all systems still go for launch?
As the countdown clock kept ticking, a crowd of scientists, mission planners, family, friends—and the poet laureate of the United States—gathered outside under a clear blue sky to watch. Then, they started counting down together.

Fire and billowing smoke were visible first. A few seconds passed before the rocket’s roar could be heard. As it lifted higher in the sky and turned out over the ocean, vibrations from the boosters rushed back toward land, rumbling through one’s entire body, drawing tears and then cheers. US Poet Laureate Ada Limón, who wrote an original poem for the mission, wiped a tear from her eye and kept watching as she saw it disappear into the sky.
“I kept thinking, is all of this ok?” she said. “I don’t know. Then everyone started clapping.”


Exactly two years ago, on Oct. 14, 2022, an invitation arrived from NASA’s Jet Propulsion Laboratory for Limón to write a poem—to serve as a message from Earth and help convey the mission’s quest for knowledge. Limón agreed almost immediately and then got to the hard work of composing a poem within three short months.
On early drafts, Limón said she felt as if she was failing. She was trying to write about Europa and to educate people about the mission details she’d received from NASA. But it wasn’t working.
“You need to stop writing a NASA poem and start writing a poem you would actually write,” Limón’s husband, Lucas Marquardt, told her. So, Limón started drafting a poem about Earth, our most beloved planet and one of her best inspirations for poetry. “That’s when my poem took off,” she said.
She wrote of the mysteries of Earth, “the whale song, the songbird singing”—and how it is “the offering of water” that unites us.
“O second moon, we, too, are made of water, of vast and beckoning seas,” Limón wrote.
“In Praise of Mystery: A Poem for Europa,” was engraved on the vault plate of Europa Clipper along with a chip containing the names of 2.6 million people who signed on to her poem as a message from Earth. The poem was also just published by Norton Young Readers in October as a picture book with illustrations by Peter Sís.
On the eve before the poem was launched into space, Limón told mission scientists, engineers and family members who gathered for a “star party” that even though the poem is set to travel billions of miles on Europa Clipper, “every word is written in praise of this planet”—because every NASA scientist knows Earth is “the best planet,” she said.

“It has been the honor of my life to work on this project,” Limón told the mission team. “I propose that if this is the beginning of the journey for the Clipper that it might also be the beginning of a journey for us. And might we think about where we will be in the next five to six years? Who we will be? Who we have helped? . . . The small kindnesses, the large kindnesses. Any of those things. The possibilities of humankind.”


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Robert Pappalardo, the mission’s lead scientist, and Jordan Evans, the project manager, presented Limón and the Library with an exact replica of the vault plate from the spacecraft, engraved with Limón’s poem. Like the replica of the Voyager space mission’s golden record that carried “The Sounds of Earth” into interstellar space in 1977 (now on view in the Library’s Treasures Gallery), the Europa Clipper vault plate will have a home forever in the national library in the Rare Book and Special Collections Division to match the one exploring our solar system. The vault plate replica is set to be formally transferred to the Library in December.