James' World 2

Natalie Batalha was itching for data from the James Webb Space Telescope. It was a few months after the telescope had reached its final orbit, and her group at the University of California, Santa Cruz, had been granted time to observe a handful of exoplanets—planets that orbit around stars other than our sun.

Among the targets was WASP-39b, a scorching world that orbits a star some 700 light-years from Earth. The planet was discovered years ago. But in mid-July, when Batalha and her team got their hands on the first JWST observations of the distant world, they saw a clear signature of a gas that is common on Earth but had never been spotted before in the atmosphere of an exoplanet: carbon dioxide. On Earth, carbon dioxide is a key indicator of plant and animal life. WASP-39b, which takes just four Earth days to orbit its star, is too hot to be considered habitable. But the discovery could well herald more exciting detections—from more temperate worlds—in the future. And it came just a few days into the lifetime of JWST. “That was a very exciting moment,” says Batalha, whose group had gathered to glimpse the data for the first time. “The minute we looked, the carbon dioxide feature was just beautifully drawn out.”

This was no accident. JWST, a NASA-led collaboration between the US, Canada, and Europe, is the most powerful space telescope in history and can view objects 100 times fainter than what the Hubble Space Telescope can see. Almost immediately after it started full operations in July of 2022, incredible vistas from across the universe poured down, from images of remote galaxies at the dawn of time to amazing landscapes of nebulae, the dust-filled birthplaces of stars. “It’s just as powerful as we had hoped, if not more so,” says Gabriel Brammer, an astronomer at the University of Copenhagen in Denmark.