By spotting these strong carbon dioxide features, we have shown there is a sizable fraction of heavier elements, like carbon, oxygen, and iron, in these planets’ atmospheres,” said William Balmer, of Johns Hopkins University in Baltimore.

The James Webb Space Telescope is a collaborative effort between NASA, the European Space Agency and the Canadian Space Agency. Unlike the Hubble Space Telescope, which orbits around the Earth, Webb orbits the sun at a distance of about 1 million miles away from Earth.