Hubble Space Telescope

Hubble Space Telescope

1. history

   • carried aboard the space shuttle Discovery on April 24 1990
   • named after Edwin Hubble, an American astronomer of the 20th Century

2. key discoveries and advancements

   • finding the age of the universe
   • Discovering 4 of the 5 moons that orbit Pluto
   • Tracking seasonal changes on other planets
   • Exoplanet science

3. functioning

   • Cassegrain reflector
     • light hits the primary mirror and bounces off it onto the secondary mirror, which focuses light through a hole in the centre of the primary mirror leading to the scientific instruments
   • Completes an orbit of the Earth every 97 minutes (about 8km per second)
   • instruments
     • wide field camera 3
       • sees 3 different kinds of light: near-ultraviolet, visible, near-infrared
       • will be used to study: dark energy, dark matter, formation of individual stars, discovery of extremely remote galaxies previously beyond Hubble's vision
     • Cosmic Origins Spectrograph
       • spectrograph that sees exclusively in ultraviolet light
       • separates light into its component colours, providing a wavelength of the object. This tells us about its: temperature, chemical composition, density and motion
     • Advanced Camera for Surveys
       • Sees visible light
       • Designed to study early activity in the universe
       • Helps map the distribution of dark matter, distant objects, searches for large planets, studies evolution of clusters of galaxies
     • Space Telescope Imaging Spectrograph
       • spectrograph that sees ultraviolet, visible and near-infrared light
       • works best with small light sources (e.g. stars, quasars), but can map out large objects, e.g. galaxies
     • Near Infrared Camera and Multi-Object Spectrometer
       • heat sensor (infrared light)
       • can observe objects hidden by interstellar dust, e.g. stellar birth sites
     • Fine Guidance Sensors
       • keep the Hubble pointed in the right direction by locking onto 'guide stars'
       • can be used to precisely measure the distance between stars, and their relative motions
   • All functions powered by sunlight, using solar arrays that convert sunlight directly to electricity