NASA's James Webb Space Telescope, built to give the world its first glimpse of the universe as it existed when the earliest galaxies formed, was launched by rocket early Saturday from the northeastern coast of South America, opening a new era of astronomy.

The revolutionary $9 billion infrared telescope, described by NASA as the premiere space-science observatory of the next decade, was carried aloft inside the cargo bay of an Ariane 5 rocket that blasted off at about 7.20 am EST (1220 GMT) from the European Space Agency's (ESA) launch base in French Guiana.

The flawless Christmas Day launch, with a countdown conducted in French, was carried live on a joint NASA-ESA webcast.