The JWST, the world’s largest and most powerful telescope, now has all of its mirrors aligned and in focus. The crew has produced a series of breathtaking photographs to commemorate the milestone, demonstrating exactly how sharp the observatory is. Not only are its critical instruments exceptionally crisp, but even the fine guiding sensors, which are merely used for positioning, produced stunning photos. This is a true testament to the telescope’s power.
In a statement, Lee Feinberg, JWST optical telescope element manager at NASA’s Goddard Space Flight Center, said, “These remarkable test images from a successfully aligned telescope demonstrate what people across countries and continents can achieve when there is a bold scientific vision to explore the universe.” The telescope’s optical performance “continues to be better than the engineering team’s most optimistic forecasts,” according to NASA.
From the telescopes initial photons of light caught through its early, fuzzy first image, its first clear image, and now these stunning engineering photographs, it’s been quite a ride. The telescope is made up of 18 hexagonal mirrors that have to be oriented with extreme accuracy. The difference between the two segments couldn’t be more than 3.8 cm if each part was the size of Texas (1.5 inches). These mirrors direct completely focused light from space down into the telescope’s four instruments, each of which effectively captures photos from that light.
There are still other calibrations to be done to validate its thermal stability, such as aiming toward different locations of the sky while maintaining the extremely low temperatures at which its instruments must be kept. The commissioning phase for the telescope’s scientific equipment is next on the agenda. Each one will be checked and adjusted to ensure that they are genuinely ready to begin the scientific mission, which should begin in late June if everything goes well.
The first image with all 18 of the JWST’s mirror capabilities combined has been revealed. Although it appears to be a simple photograph of a star, astronomers are virtually breathless with awe at the power exhibited in this single image. “The Webb team set out to create the most powerful telescope anybody has ever deployed in orbit more than 20 years ago and came up with an innovative optical design to achieve challenging research goals,” NASA’s Dr Thomas Zurbuchen said in a statement. “Today, we can confidently state that design will deliver.”
The JWST’s optics are meeting or exceeding expectations in every way, prompting NASA’s Dr Ritva Keski-Kuha to declare, “We now know we constructed the appropriate telescope,” something many disputed during the observatory’s extended delays. The picture above depicts the end of the “fine phasing” stage. The performance of the mirror thus far has been so outstanding that the JWST’s operators are convinced that the world’s biggest space telescope will fulfill, if not exceed, the scientific goals for which it was designed.
The resolution, or the smallest item that can be recognized with it, is one of the most critical characteristics of a telescope. The image has a resolution of 70 milliarcseconds, which is 28 times better than the Spitzer Space Telescope, which was previously the most powerful infrared telescope. After rectification, the performance is comparable to Hubble’s, but at longer wavelengths that Hubble cannot see.
