Wayback Machine

Thus far the telescope, bristling with cameras, spectroscopes and other instruments, is exceeding expectations. (Its resolving power is twice as good as advertised.) The telescope’s flawless launch, Rigby reported, has left it with enough maneuvering fuel to keep it working for 26 years or more.

“These are happy numbers,” she said as she and her colleagues rattled off performance statistics of their instruments. Rigby cautioned that the telescope’s instruments were still being calibrated, so the numbers might yet change.

Perhaps the biggest surprise from the telescope so far involves events in the early millenniums of the universe. Galaxies appear to have been forming, generating and nurturing stars faster than battle-tested cosmological models estimated. “How did galaxies get so old so fast?” asked Adam Riess, a Nobel physics laureate and cosmologist from Johns Hopkins University who dropped in for the day.

Exploring that province — “cosmic spring,” as one astronomer called it — is the goal of several international collaborations with snappy acronyms such as JADES (JWST Advanced Deep Extragalactic Survey), CEERS (Cosmic Evolution Early Release Science), GLASS (Grism Lens-amplified Survey From Space) and PEARLS (Prime Extragalactic Areas for Reionization and Lensing Science).

Webb’s infrared vision is fundamental to these efforts. As the universe expands, galaxies and other distant celestial objects are speeding away from Earth so fast that their light has been stretched and shifted to invisible, infrared wavelengths. Beyond a certain point, the most distant galaxies are receding so quickly, and their light is so stretched in wavelength, that they are invisible even to the Hubble telescope.

The Webb telescope was designed to expose and explore these regions, which represent the universe at just 1 billion years old, when the first galaxies began to bloom with stars. “It takes time for matter to cool down and get dense enough to ignite stars,” noted Emma Curtis-lake, of the University of Hertfordshire and a member of the JADES team. The rate of star formation peaked when the universe was 4 billion years old, she added, and has been falling ever since. The cosmos is now 13.8 billion years old.

Cosmic distances are measured with a parameter called redshift, which indicates how much the light from a faraway object has been stretched. Just a few months ago a redshift of 8, which corresponds to a time when the universe was about 646 million years old, was considered a high redshift.

Thanks to Curtis-lake and her colleagues, the record redshift is now 13.2, corresponding to when the universe was only 325 million years old.

Curtis-lake and her team had aimed the telescope at a patch of sky called GOODS South, looking for galaxies