JWST’s main mirror before launch. Image credit: NASA/Chris Gunn Credit: NASA/Chris Gunn
A revolutionary way to study the universe is almost here. The JWST, the successor to Hubble, is about to begin its scientific mission and its first real color images will be revealed to the world on Tuesday July 12. The space observatory has been in the making for a long time, and now NASA has revealed the five targets we’ll be looking at.
Next week we’ll see how JWST sees the Carina Nebula, one of the brightest and largest in the sky. JWST’s infrared observations will bring even more detail to a well-studied object. The nebula is a stellar nursery, among its swirls and clouds, new stars are born, and JWST has the power to see them clearly. The nebula is located 7,500 light years from Earth.
The Carina Nebula seen by Hubble in 2009. Image credit: NASA, ESA and the Hubble SM4 ERO team
Another nebula will also be revealed. The South Ring Nebula, about 2,000 light-years away, is the expanding gas shell of a binary star system where a star has lost its gaseous envelope and transformed into a white dwarf.
South Ring Nebula seen in Infrared by Spitzer. Image Credit: NASA/JPL-Caltech/J. Hora (Harvard-Smithsonian CfA)
The third target in our galaxy is exoplanet WASP-96b. We won’t see a picture of it. JWST will just take a spectrum of it, to understand in detail the composition of its atmosphere. This distant world is located 1,150 light years from Earth. Its mass is half that of Jupiter, but it orbits its star in just 3.4 days. In 2018, it was determined to be the first cloudless exoplanet.
Much further away is Stephen’s Quintet, one of the oldest known compact galaxy groups. Four of the five galaxies are actually a real group in space and don’t just appear in the sky. They have been interacting with each other for eons, creating structures full of activity that should be spectacular when viewed in glorious infrared detail by JWST. The galaxies are located 290 million light-years away.
Stephan’s Quintet seen by Hubble. The galaxy without interaction is the bottom one. Image credit: NASA, ESA and the Hubble SM4 ERO team
Last but not least is SMACS 0723, a cluster of galaxies known for its incredible mass, with its central galaxy alone weighing 358 billion times the mass of our Sun. It is located 4.2 billion light-years away and its enormous mass warps spacetime, acting as a gravitational lens magnifying background galaxies that are much fainter and farther away.
This is just the start of JWST, a collaborative effort between the European Space Agency, the Canadian Space Agency and NASA. The comparison between its capabilities and its infrared predecessor Spitzer has already blown us away and we can’t wait to see those historic images on Tuesday.
Sharpness comparison of JWST vs. Spitzer. Image credit: Spitzer: NASA/JPL-Caltech; MIRI: NASA/ESA/CSA/STScI