Differences Between the James Webb Telescope and Hubble Space Telescope
The Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST) are two extraordinary space-based observatories that have revolutionised our understanding of the cosmos. While they share a common goal of exploring the universe, they differ significantly in their capabilities, primarily in the types of light they observe, their mirror sizes, and their scientific capabilities.
The Hubble Space Telescope, launched in 1990, primarily observes visible and ultraviolet light, providing detailed images of stars, galaxies, and nebulae in those wavelengths. On the other hand, the James Webb Space Telescope, which was launched in 2021, specialises in infrared light, allowing it to see through dusty regions invisible to Hubble and revealing hidden structures and cooler objects.
The key differences between these two telescopes can be summarised as follows:
| Feature | Hubble Space Telescope | James Webb Space Telescope | |----------------------------------|--------------------------------------------------------|----------------------------------------------------------| | **Wavelength Observed** | Primarily optical (visible) and ultraviolet light | Specialises in infrared light | | **Primary Mirror Size** | 2.4 meters in diameter | 6.5 meters in diameter | | **Capability Highlights** | Captures detailed images in visible light, showing glowing gases, star formation, and ultraviolet phenomena | Can see through dense clouds of cosmic dust and gas, revealing hidden structures and cooler objects | | **Resolution and Sensitivity** | High, but limited by smaller mirror and visible/UV range | Higher resolution and sensitivity, especially in the infrared, due to larger mirror and advanced instruments |
These differences enable Hubble and Webb to contribute to our understanding of the universe in complementary ways. Hubble's images have unveiled the cosmos in ways previously impossible, showing star birth and death, galaxy shapes, and nebulae details with sharp clarity. In contrast, Webb penetrates dusty regions invisible to Hubble, revealing phenomena such as star nurseries hidden inside nebulae and fine structures within galaxies.
One of the most significant achievements of the JWST was in 2024, when it broke several records at NASA, including its ability to peer deep into galaxies undergoing rapid star formation, such as the Cigar Galaxy (M82), revealing stellar nurseries obscured in visible light images captured by Hubble.
Together, these telescopes offer a more complete picture of the universe, enabling breakthroughs in understanding star formation, galaxy evolution, and the cosmic expansion rate. The combination of data from both telescopes led to a more accurate determination of the Hubble constant (around 70.4 km/s/Mpc), reducing discrepancies and helping confirm existing cosmological models.
The JWST's first full-color image was of the Carina Nebula, a star-forming region 7,500 light-years from Earth. This image, captured in infrared for the first time by the JWST, revealed the nebula's 3D structure and finer details more clearly than ever before. René Doyon, a principal investigator on the JWST mission, described the Carina Nebula image as an "art piece."
The differences between Hubble and Webb reveal humanity's perspectives towards observing the cosmos. While Hubble lets us look far, Webb lets us look deep. To this day, Hubble's images continue to fill textbooks, headlines, and laptop backgrounds around the globe, fundamentally reshaping how we see the cosmos. Meanwhile, Webb, along with Hubble, helps answer questions about the universe that were previously out of reach.
From jaw-dropping images of supernovae and nebulae to refining critical measurements like the Hubble constant, these telescopes have significantly advanced our understanding of the universe. Their legacy will continue to inspire and inform generations to come, as they continue to unveil the mysteries of the cosmos.
Science has benefited immensely from the Hubble Space Telescope and the James Webb Space Telescope, both remarkable space-based observatories that have expanded our understanding of the universe. The Hubble Space Telescope primarily operates in visible and ultraviolet light, illuminating the cosmos with detailed images of stars, galaxies, and nebulae. On the other hand, the James Webb Space Telescope specializes in infrared light, allowing it to explore hidden structures and cooler objects obscured by dusty regions invisible to Hubble. As technology advances, these space-and-astronomy tools continue to revolutionize our knowledge of space and unlock its secrets.
