The powerful Webb telescope found water in this alien planet's clouds

The most amazing discoveries will not come from pretty pictures.

The instrument can detect what the atmosphere of distant planets are made of. A hazy exoplanet 1,150 light-years away has been found to have a distinctive signature of water.

It's not the first time water has been found on another planet. The telescope built with a 21-foot mirror is more than two-and-a-half times larger than Hubble's.

The space agency said that while the Hubble Space Telescope has analyzed numerous exoplanet atmospheres over the past two decades, capturing the first clear detection of water in 2013).

25 percent of the telescope's first year was spent peering into the skies of exoplanets There is a world called WASP-96 b. Our solar system doesn't have a "hot Jupiter" like this one. WASP-96 b is a world smaller than Jupiter, which is a gas giant. The temperature is higher than a pizza oven.

Astronomers point the telescope at known exoplanets, which are planets outside our solar system. They do something very clever.

They'll wait for planets to travel in front of their bright stars. This starlight passes through the exoplanet's atmosphere, then through space, and ultimately into instruments called spectrographs aboard Webb (a strategy called "transit spectroscopy"). They're essentially hi-tech prisms, which separate the light into a rainbow of colors. Here's the big trick: Certain molecules, like water, in the atmosphere absorb specific types, or colors, of light. "Each molecule has a specific diet," explained Néstor Espinoza, an exoplanet researcher at the Space Telescope Science Institute, which runs the James Webb Space Telescope.

So if that color doesn't show up in the spectrum of colors observed by a Webb spectrograph, that means it got absorbed by (or "consumed" by) the exoplanet's atmosphere. In other words, that element is present in that planet's skies. The spectrograph produces lines (designating different types of light), not pretty pictures; but it's a wealth of invaluable information.

The spectrum of light shows that WASP-96 b blocks light waves from the water in the clouds.

The atmospheric composition of WASP-96 b, which indicates the presence of water. Credit: NASA / ESA / CSA / STScI

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The detailed data was captured by the NIRISS while it was peering at WASP-96 b. Planetary scientists are looking forward to finding more on other worlds. NASA said that the NIRISS observation shows that the power of the telescope is to study the atmospheres of exoplanets.

The telescope will be pointed at smaller, rocky, Earth-like worlds. There could be trillions of planets in our universe. We don't really know much about them.

The Space Telescope Science Institute has only been able to scratch the surface.