The powerful James Webb Space Telescope's inaugural batch of images has opened a new chapter of cosmic exploration, but astronomers say the observatory's most consequential discoveries may well be those they have yet to even imagine.

Distant colliding galaxies, gas-giant exoplanets and dying star systems were the first celestial subjects captured by the multibillion-dollar observatory, putting its wide range of infrared-imaging capabilities on colorful display and proving the telescope works as designed.

Webb's gallery of early photos and spectrographic data, which astronomers likened to the results of mere "target practice" as they readied the telescope for operational science, also previewed several planned areas of inquiry ahead.

The competitively-selected agenda of research includes exploring the evolution of early galaxies, the life cycle of stars, the search for habitable planets orbiting distant suns, and the composition of moons in our own outer solar system.

But the most revolutionary findings by Webb, 100 times more sensitive than its 30-year-old predecessor, the still-operational Hubble Space Telescope, may turn out to be accidental discoveries or answers to questions astronomers have yet to ask.

"Who knows what's coming for JWST. But I'm sure we're going to have a lot of surprises," René Doyon, principal investigator for one of Webb's instruments, the Near-Infrared Imager and Slitless Spectrograph, said Tuesday at NASA's Goddard Space Flight Center in Maryland, where the agency unveiled the observatory's first full-color images.

With Webb open for business seven months after its launch in December, astronomers are preparing for "something that's out there that we never guessed would be there at all," said John Mather, a Nobel Prize-winning senior astrophysicist at NASA whose work during the 1990s helped cement cosmology's 'Big Bang' theory.