Wavelength Sensitivity of Hubble, Webb, Roman, and Other Observatories

Planets, stars, galaxies, and other objects in space give off a wide range of visible and invisible forms of light. Because different forms of light have different characteristics, no single observatory can detect all wavelengths. Astronomers typically rely on data from multiple ground- and space-based telescopes to fully understand the objects and phenomena they are studying. 

This illustration shows the wavelength sensitivity of a number of current and future space- and ground-based observatories, along with their position relative to the ground and to Earth’s atmosphere.

The wavelength bands are arranged from shortest (gamma rays) to longest (radio waves). The vertical colour bars show the relative penetration of each band of light through Earth’s atmosphere. 

From left to right: 

The Fermi Gamma-ray Space Telescope detects gamma rays. Fermi is in low-Earth orbit, just above the bulk of Earth’s atmosphere, which blocks gamma rays. (Launched in 2008)

The Chandra X-ray Observatory detects X-rays. Chandra orbits Earth high above the atmosphere, which absorbs X-rays. (Launched in 1999)

The Hubble Space Telescope detects ultraviolet, visible, and near-infrared light. Hubble is in low-Earth orbit, just above the bulk of Earth’s atmosphere, which blocks some wavelengths of ultraviolet and near-infrared light. (Launched in 1990)

The ground-based Rubin Observatory in Chile is designed to survey ultraviolet, visible, and near-infrared light that makes it through the atmosphere. (Scheduled to begin full science survey operations in October 2024)

Ground-based Extremely Large Telescopes (ELTs), such as the Giant Magellan Telescope, the European ELT, and the Thirty Meter Telescope, will also detect ultraviolet, visible, and near-infrared light. (Scheduled to begin operations in 2027)

The Euclid spacecraft is designed to survey visible and near-infrared light. Euclid will orbit the Sun at Lagrange Point 2 (L2), about one million miles from Earth. (Scheduled for launch in Q3 of 2023)

The Nancy Grace Roman Space Telescope will survey visible and near-infrared light. Roman will orbit the Sun at L2. (Scheduled to launch by May 2027)

The James Webb Space Telescope is sensitive to visible (red) to mid-infrared light. Webb is currently orbiting the Sun at L2. (Launched 25 December 2021)

The Stratospheric Observatory for Infrared Astronomy (SOFIA), a flying observatory, is primarily used to observe ultraviolet, visible, and near-infrared. SOFIA flies just above the lowest layer of Earth’s atmosphere. (Began flying in 2010)

The ground-based Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile detects microwave light, which passes all the way through Earth’s atmosphere. (Began observations in 2011)

The ground-based Square Kilometre Array (SKA) in Australia is designed to detect radio waves that pass through the atmosphere. (Scheduled to begin operation in 2028)

Image credit: NASA, STScI

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