“The engineering images that we saw today are as sharp and as crisp as the images that Hubble can take, but are at a wavelength of light that is totally invisible to Hubble. “The telescope’s performance so far is everything that we dared to hope,” says Jane Rigby, Webb operations project scientist at Goddard. The relief that accompanies this stellar portrait is almost tangible. Until now, there has been no way to confirm how well the process has unfolded, and the wait for these first images has been a nervous one. The alignment of each of these segments to complete a single, smooth reflecting surface requires nanometre-scale precision. The telescope’s main mirror is 6.5 metres wide, and composed of 18 hexagonal segments that self-assembled in space. Credit: STScI / NASAīut since its launch in December 2021, every stage of deployment has progressed flawlessly. In this image, all of Webb’s 18 primary mirror segments are shown collecting light from the same star in unison. This configuration is not used during scientific operations and is used strictly for engineering and alignment purposes. This new “selfie” was created using a specialized pupil imaging lens inside of the NIRCam instrument that was designed to take images of the primary mirror segments instead of images of the sky.
The pressure to ensure each and every component of the telescope was perfect before launching it into space was enormous, and led to a number of delays. While this extends our view of deep space phenomenally, it also means that we have no option to make adjustments or repairs if something goes awry. The $US10 billion dollar telescope is staggeringly complex in design, and the stakes are high – where the Hubble telescope orbits the Earth, within our reach to service, James Webb sits approximately 3000 times further away, orbiting the Sun. These first images are not scientific – instead, they’re engineering images, designed to test how smoothly all the many parts of this engineering marvel are working together. The performance is as good if not better than our most optimistic prediction.” And I’m happy to say that the optical performance of the telescope is absolutely phenomenal, it is really working extremely well. “We said last fall that we would know that the telescope is working properly when we have an image of a star that looks like a star,” says Lee Feinberg, Webb optical telescope element manager at NASA’s Goddard Space Flight Center. In a virtual briefing, NASA officials expressed their overwhelming joy and relief at what these first images represent. Each is a distant galaxy, and this is the first time we’ve ever been able to capture them. The star itself is of little interest, lovely though its image is – instead, astronomers are captivated by the spray of tiny dots scattered across the background.
The star, known as HD84406, is 100 times fainter than what can be seen with the human eye. Having completed the self-assembly of its 18-segmented main mirror, the telescope has now taken exceptional images of an unexceptional star as a test of its capabilities. Images of a very “boring” star are making waves across the astronomical world today – they are the first sent back from NASA’s James Webb telescope, and they have exceeded all hopes and expectations. Perseverance Mars rover damaged by pebble flung in gust, but functioning fine.How big is the Sun? An exercise in really big numbers.New telescopes at Siding Spring to detect gravitational waves.ANU researchers witness birth of tight binary star system for the first time.NASA fires its first Australian rocket launch in 27 years from Arnhem land.