Space Telescope
A space telescope is an astronomical instrument placed in orbit above Earth's atmosphere to observe celestial objects across a wide range of electromagnetic wavelengths without atmospheric distortion or absorption. Unlike ground-based observatories, space telescopes can detect ultraviolet, X-ray, infrared, and gamma-ray radiation that is blocked by the atmosphere. Iconic examples include the Hubble Space Telescope, the James Webb Space Telescope, and the Chandra X-ray Observatory.
Major Space Telescopes and Their Wavelength Coverage
| Telescope | Launch Year | Wavelength | Primary Mirror (m) | Key Discovery |
|---|---|---|---|---|
| Hubble (HST) | 1990 | UV / Visible / Near-IR | 2.4 | Accelerating universe expansion |
| Spitzer | 2003 | Infrared | 0.85 | Exoplanet atmospheres |
| Chandra | 1999 | X-ray | 1.2 | Black hole jets |
| James Webb (JWST) | 2021 | Near-IR / Mid-IR | 6.5 | Earliest galaxies |
| Fermi | 2008 | Gamma-ray | N/A | Gamma-ray bursts |
Interactive Tools
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Related Terms
SETI
SETI, the Search for Extraterrestrial Intelligence, is the scientific effort to detect signals or evidence of technological civilizations beyond Earth by monitoring the electromagnetic spectrum, particularly radio and optical wavelengths, for non-natural patterns. The SETI Institute, founded in 1984, uses radio telescope arrays such as the Allen Telescope Array to systematically scan the sky for anomalous signals. The Drake Equation, formulated by Frank Drake in 1961, provides a probabilistic framework for estimating the number of communicating civilizations in the Milky Way.
Astrobiology
Astrobiology is the interdisciplinary scientific study of the origin, evolution, distribution, and future of life in the universe. It combines elements of astronomy, biology, chemistry, and geology to investigate whether life exists or could exist beyond Earth. The field explores extreme environments on Earth as analogs for potential habitable zones on other planets and moons such as Mars, Europa, and Enceladus.
Gravitational Assist
A gravitational assist, also known as a gravity slingshot or swing-by maneuver, is a technique in which a spacecraft uses the gravity and relative motion of a planet or moon to gain speed and change its trajectory without using any additional fuel. As the spacecraft approaches the planet, it falls into the gravitational field, accelerates, curves around the planet, and exits with increased velocity relative to the Sun. NASA's Voyager 1 used multiple gravitational assists past Jupiter and Saturn to reach interstellar space, while the Cassini mission used four assists to reach Saturn.
From Greek "tele" (far) + "skopein" (to look). The concept of a space-based telescope was first proposed by Lyman Spitzer Jr. in 1946 in a paper titled "Astronomical Advantages of an Extra-Terrestrial Observatory."