The U.S. space agency NASA is inviting people to have their names engraved on a microchip bound for a moon of Jupiter. The spacecraft Europa Clipper will set off for Jupiter's moon Europa. The craft is set to embark on its 2.6-billion-kilometre voyage in October 2024. The journey through the heavens will take six years. Sending the names is part of a time-capsule project called "Message in a Bottle". The names will be etched next to a piece of poetry by U.S. poet Ada Limon called, "In Praise of Mystery: A Poem for Europa". NASA said: "The poem connects the two water worlds – Earth, yearning to reach out and understand what makes a world habitable, and Europa, waiting with secrets yet to be explored."

More than 700,000 names have already been submitted to NASA. Engineers will use an electron beam to stencil them onto a tiny silicon microchip. NASA said: "Each line of text is smaller than 1/1000th the width of a human hair (75 nanometres)." It added: "Riding on the exterior of the spacecraft, the poem and names will be like a message in a bottle as they make about 50 close flybys of [Europa's] ocean world." Europa is one of Jupiter's 95 officially recognized moons. The Europa Clipper will gather data on the moon's atmosphere, icy crust and ocean. NASA said: "Europa is such a promising place to better understand the astro-biological potential for habitable worlds beyond Earth."