The Hubble Space Telescope (HST) is a large, space-based observatory that orbits Earth and provides high-resolution images and data of astronomical objects. Launched in 1990 by NASA aboard the Space Shuttle Discovery, Hubble was a collaborative project between NASA and the European Space Agency (ESA).
Type of Telescope:
Hubble is a reflecting telescope, specifically a Cassegrain reflector. Here’s what that means:
- Reflecting Telescope: It uses mirrors rather than lenses to collect and focus light.
- Cassegrain Design: This configuration involves a large primary concave mirror and a secondary convex mirror that reflects the light back through a hole in the center of the primary mirror to the instruments behind it.
Key Features:
- Primary mirror size: 2.4 meters (7.9 feet) in diameter
- Wavelengths observed: Primarily visible light, but also ultraviolet and a bit of infrared
- Orbit: Low Earth orbit, about 547 km (340 miles) above Earth’s surface
- No atmospheric distortion: Because it’s above Earth’s atmosphere, Hubble captures much clearer images than ground-based telescopes.
Scientific Contributions:
Hubble has made major contributions to astronomy, such as:
- Determining the rate of expansion of the universe (Hubble constant)
- Discovering that most galaxies contain supermassive black holes
- Imaging distant galaxies, nebulae, and exoplanets
- Helping refine the age of the universe