The targets for Webb's first public images, expected to be released Tuesday, include:
The Carina Nebula: A vast star-forming region in the constellation Carina some 7,600 light-years from Earth that's four times as large as the Orion Nebula. The Carina Nebula is the home of the most luminous known star in the Milky Way, as well as the Eta Carinae binary system, which includes a massive sun expected to explode in a supernova blast in the near future (astronomically speaking).
Southern Ring Nebula: An expanding cloud of gas 1 half light-year across that was ejected from a dying star. Relatively low-mass stars like Earth's sun will end their lives by blowing off their outer layers, forming so-called "planetary nebulas" while their cores shrink and slowly cool.
Stephen's Quintet: A collection of five galaxies in the constellation Pegasus 290 million light-years from Earth that was discovered in 1877, the first such close-together grouping of galaxies to be detected. Four of the five galaxies are gravitationally interacting in a slow-motion merger.
WASP-96b: An unusual cloudless exoplanet 1,150 light-years away that's about half the size of Jupiter, orbiting its sun every 3.4 days. By spectroscopically analyzing light from the parent star as it passes through the exoplanet's atmosphere on the way to Earth, astronomers can tease out details about its chemical composition.
SMACS J0723.3-7327: The combined gravity of countless stars in huge galaxy clusters like this one can act as a powerful lens if the alignment is just right, magnifying the light from more distant objects in the far background to provide a deeper look back across space and time than would otherwise be possible.