The James Webb Space Telescope can see in much greater detail and look further back in time than any other telescope in the world.
The Hubble Space Telescope was deployed into Earth’s orbit by the Space Shuttle Discovery over 30 years ago. Since then, Hubble has captured stunning images that are not only visually breathtaking but also provide invaluable scientific insights, revealing that the expansion of the universe is actually accelerating due to a mysterious force known as dark energy.
Even to this day, Hubble remains a remarkable tool for astronomy and will continue to support scientific research for many years to come — but scientists wanted more, which is why we now have the James Webb Space Telescope (JWST).
The Hubble Space Telescope operates in Earth’s orbit at an altitude of approximately 610 km, about 220 km higher than the altitude of the International Space Station (ISS). Traveling at a speed of about 7,500 m/s, Hubble can complete one orbit around Earth in 97 minutes, making 15 orbits each day.
Hubble is equipped with a range of instruments powered by solar energy, designed to capture images of the universe in visible light, ultraviolet (UV), and near-infrared wavelengths. Naturally, all of Hubble’s instruments are designed to function outside of Earth’s atmosphere, and many would be rendered ineffective if placed on the ground.
Image of the galaxy cluster SMACS 0723.
You may have seen the first stunning images released by NASA from JWST last week, and they truly demonstrate its superior capabilities compared to other space telescopes.
The image of the SMACS 0723 galaxy cluster shows dozens of galaxies that are 13 billion light-years away from us. The differences are striking, particularly the much clearer gravitational lensing effects that help magnify and bend light from distant objects.
Or the image of the Southern Ring Nebula, showcasing a vibrant shell of gas and dust stretching over 1.3 light-years, which contains a dying star within.
Image of the Southern Ring Nebula
These unprecedented sharp images are due to the JWST being approximately 100 times more sensitive than Hubble thanks to its larger light-collecting mirror. However, the biggest difference between the two is that Hubble primarily conducts observations in visible and ultraviolet wavelengths, while the $10 billion JWST mainly observes in the mid-infrared and near-infrared.
The main mirror of Webb is 6.5 meters in diameter, compared to Hubble’s much smaller 2.4 meters. This means that Webb can cover more than 15 times Hubble’s field of view.
The JWST’s sensitivity to much longer wavelengths allows it to see through dust clouds that often obscure stars, planetary systems, and distant galaxies from Hubble’s view.
This means that JWST is highly sensitive, enabling it to reveal the atmospheric composition of distant exoplanets. It can also look much further back in time and in much greater detail compared to Hubble. At this moment, no other tool besides JWST can observe the first galaxies formed 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 Hubble Space Telescope.
Similarly, the Carina Nebula is seen in much greater detail through the lens of James Webb, with each bright dot representing a different star. Thanks to sensitive infrared instruments, Webb can clear away the webs of gas and dust, revealing not only hundreds of new stars but also holes and stellar winds blowing from very young stars.
For a long time, the evolution of the universe (according to the Big Bang Theory) from the universe’s inception to the emergence of the first stars still has a gap (known as the Dark Age). Scientists hope that the James Webb Telescope can help them clarify this issue.
“The James Webb Space Telescope is a monumental achievement, built to change our view of the universe and provide remarkable scientific insights,” stated NASA Administrator Bill Nelson. “Webb will look back over 13 billion light-years, to the time just after the Big Bang, with enough power to show humanity the farthest point in space we have ever seen. Right now, we are very close to unlocking the mysteries of the universe, thanks to the skills and expertise of the incredible team behind it.”
The James Webb Space Telescope will open a new chapter in the history of astronomy in particular, and human history in general. Like all other advanced research instruments worth billions of dollars, James Webb is sure to deliver unprecedented data in history, helping us understand more about the universe and humanity’s place in the timeline. And all that we have just mentioned is just the beginning, and over time, JWST will unveil more and more secrets of the universe.
