neb·u·lous
/ˈnebyələs/
adjective
in the form of a cloud or haze; hazy.
“a giant nebulous glow”
(of a concept or idea) unclear, vague, or ill-defined.
“nebulous concepts like quality of life”
Similar— indistinct, indefinite, unclear, vague, hazy, cloudy, fuzzy, misty, lacking definition, blurred, blurry, out of focus, foggy, faint, shadowy, dim, obscure, shapeless, formless, unformed, amorphous, nebulose
Opposite— clear
[Definition from Oxford Languages]
One can see why astronomers are excited about the pictures from the James Webb telescope, when you put them next to pictures of Hubble (launched 30 years ago in 1990).
The Webb telescope works with infrared light and can peer through cosmic dust to provide pictures with more detail and depth.
Below are pictures of the Carina Nebula (a nebula is a gigantic could of gas and dust), located in the Carina–Sagittarius Arm of the Milky Way galaxy.
The nebula is some 8,500 light-years from Earth with a radius of 230 light years.
Bottom: Image taken with James Webb telescope.
The Cosmic Cliffs in the Carina Nebula in an area with New General Catalogue (NGC) number 3324. The brown stuff is the edge of the giant, gaseous cavity above it, from where massive, hot, young stars emit intense ultraviolet radiation and stellar winds.
[Description and images from NASA website]