The James Webb and Hubble Telescopes: A Thoughtful Comparison!

The Hubble Space Telescope was deployed into Earth's orbit by the space shuttle Discovery more than 30 years ago. Since then, Hubble has captured breathtaking images that are not only incredibly beautiful, but also provide invaluable scientific insight, showing that the rate of expansion of the universe is actually accelerating due to a mysterious force. something called dark energy.

Until now, Hubble is still a great tool for astronomy and it will continue to serve scientific research for many years to come - but scientists want more, and that's it. is why we now have the James Webb Space Telescope (JWST).

The Hubble Space Telescope was launched and operated in Earth's orbit at an altitude of about 610 km, about 220 km higher than the orbital altitude of the International Space Station ISS. With a speed of about 7,500 m/s, Hubble can orbit the Earth once in 97 minutes and 15 times a day.

Hubble is equipped with a full range of solar-powered instruments that capture all images of the universe in visible, ultraviolet (UV) and near-infrared wavelength light. Of course, all of the instruments on Hubble are designed to work outside of Earth's atmosphere, and if you put Hubble on the ground, a lot of the instruments will no longer work.

SMACS 0723 galaxy cluster image.

You may have seen the first stunning images from the JWST released by NASA last week, and it really shows off its capabilities compared to other space telescopes.

Image of the galaxy cluster SMACS 0723, showing dozens of galaxies 13 billion light-years away. The obvious differences are striking, including a much more obvious gravitational lensing effect, which magnifies and bends the light behind gravitationally-weighted objects.

Or this image of the Southern Ring Nebula shows a vivid shell of gas and dust more than 1.3 light-years across with a dying star inside.

Image of the Southern Ring Nebula

These unprecedentedly sharp images are due to the fact that JWB is about 100 times more sensitive than Hubble thanks to its larger light-collecting mirror. But the biggest difference between the two is that Hubble mainly makes observations in the visible and ultraviolet wavelengths, while the $10 billion JWST mainly observes in the mid-infrared and near-infrared ranges. .

Webb's main mirror is 6.5 meters in diameter, compared to Hubble's much smaller 2.4 meters in diameter. This means that Webb can cover more than 15 times the field of view of Hubble.
JWST's sensitivity to much longer wavelengths allows it to see through dust clouds that often obscure distant stars, planetary systems, and galaxies from Hubble's prying eyes.

This means that the JWST is so sensitive that it can reveal the atmospheric composition of distant alien planets. It can also see much farther in time and in much more detail than Hubble. At the present time, no instrument other than JWST can see the first galaxies forming in the universe.

James Webb cost NASA nearly $10 billion and is one of the most expensive scientific platforms ever built, comparable to the Large Hadron Collider at the European Organization for Nuclear Research (CERN) or the European Space Telescope. Hubble Space Telescope.

Similarly, the Carina Nebula is seen in much greater detail through the prism of James Webb, with each new bright dot representing a different star. Thanks to infrared-sensitive instruments, Webb was able to sweep away cobwebs of gas and dust, revealing not only hundreds of new stars, but also holes and sparks blown from very young stars.

For a long time, the evolution of the universe (according to the Big Bang theory) from the appearance of the universe to the first star appeared still has a gap (called the Dark Age). And scientists hope the James Webb telescope can help them clear up this problem.

"The James Webb Space Telescope is a great achievement, designed to change our view of the universe and provide great science lessons," said NASA director Bill Nelson. . 'The Webb telescope will look back more than 13 billion light-years, immediately after the Big Bang, with enough power to show humanity the furthest point of space we've ever seen. We are now very close to unlocking the mysteries of the universe, thanks to the skill and expertise of the amazing team behind it."

The James Webb Space Telescope will open a new chapter for the history of astronomy in particular, and the history of mankind in general. Like every other billion-dollar advanced research equipment, James Webb will certainly bring back unprecedented data, helping us better understand the universe itself as well as the place of humans in the universe. timeline. And all that we have just talked about is just the beginning, and over time JWST will reveal more and more secrets of the universe.