Exploring the Universe with the Hubble and James Webb Telescopes
Who wouldn’t love to look at the night sky, especially on a clear night, with every star twinkling back at us? Does it not invoke a sense of curiosity, a want to know what these shimmering objects look up close? This curiosity drove humans to create telescopes, first little ones, then bigger ones, giant ones, and then came telescopes put in space.
Unlike the Earth’s atmosphere which contains pockets of air and distorts light in space, space telescopes can see more and without the distraction of stars twinkling. The Hubble Telescope, a proud feat, was launched into low Earth orbit in 1990 and has provided incredibly detailed images of distant objects since. The telescope is approximately the size of a school bus and has a 7.8-foot (3m) mirror that allows it to collect light from distant objects. Although capable of observing objects in visible, ultraviolet, and infrared light, it can only see one kind of light at a time.
Hubble was not cheap: it came with a $2.5 billion price tag. What made it difficult to stomach, however, was the underwhelming advantage it offered over a ground-based telescope: a mere increase of 50% in sharpness. Investigations soon shed light on a manufacturing error that caused spherical aberration in the mirror. NASA launched a seven-person crew repair mission in 1993 to install corrective optics and new instruments.
The James Webb Space Telescope is the successor to the Hubble Space Telescope and is designed to be more powerful, with a 21 feet(6m) 4 inches(10cm) primary mirror, almost three times the size of the mirror on the Hubble Space Telescope. In addition to a larger mirror, the James Webb Space Telescope boasts advanced instruments in its arsenal, including a Near-Infrared camera, and a Near-Infrared Spectrograph. These enable the study of a wide range of celestial phenomena including the birth of stars and the formation of galaxies.
The James Webb Space Telescope was launched in December 2021 and has been placed in such a way that it can essentially maintain a fixed relative position to Earth, with only the occasional need to adjust its motion. The James Webb telescope is protected from the sun and interference by five layers of Kapton E with aluminum and doped-silicon coatings.
NASA hopes to find new insights into the most fundamental questions in astronomy from the data provided by the James Webb Telescope. This major advancement is sure to help us better understand the universe and our place in it.