Seeing into space was a challenge overcome by the invention of telescopes; they allowed us to view objects close to the Earth’s atmosphere. This barrier which protects us from harmful radiation also creates an atmospheric distortion, the twinkling of the stars and a problem for ground based telescopes. In 1977 the American government gave permission and funding to develop a large space Telescope. The Hubble Telescope was born and overcame the distortion by being sent above the atmosphere and set into orbit around our planet.
1978 saw astronauts being trained for the mission and in 1979 the first mirror was put into production. The telescope gained its name Hubble in 1983 after Edwin P Hubble; he discovered the first evidence for the expanding universe theory which Hubble has been able to study. In 1985 Hubble was completed but the tragic Challenger disaster held off its launch date.
Finally launched in 1990 by the shuttle Discovery, it continues to orbit the Earth at 353 miles (569 kilometres) above the surface and moves at five miles a second, rotating the Earth every ninety seven minutes. It is a Cassegrain reflector telescope; light hits the main mirror and is bounced to a secondary mirror where it is directed through a hole in the first mirror to scientific equipment. Solar powered, arrays collect sunlight which is turned into electricity, a portion of this is stored in batteries for the period it travels through the shadows. Inside the telescope, equipment gathers scientific data:
Fine Guidance Sensors: these keep Hubble pointing in the right direction and are able to measure distance between objects.
Advanced Camera for Surveys: its primary function is to look at the earliest moments of the universe, detecting activity as far back as possible. It helps to map dark matter and search for big planets and galaxies. It broke down in 2007 but was successfully repaired in 2009 during servicing mission four.
Near Infrared Camera and Multi Object Spectrometer: A heat sensor, it can detect objects such as baby stars which are hidden within stellar dust.
Space Telescope Imaging Spectrograph (STIS): Famous for being able to look for black holes and map galaxies, this equipment sees ultra violet, near and visible infrared light. It malfunctioned in 2004 and was also repaired during servicing mission four.
Two new components are:
Cosmic Origins Spectrograph: it sees only ultra violet but unlike STIS it studies on a much smaller level, breaking down objects like quasars to provide a finger print – the temperature, chemical components, density and motion.
Wide Field Camera 3: detects near ultraviolet light, visible and near infrared, it is used to study dark matter and energy, the formation of stars and remote galaxies.
Hubble has paved the way for many discoveries during its life:
It has revealed the age of the universe to between 13-14 billion years old.
It first showed us the possible presence of dark matter and energy.
It can see galaxies in all stages of evolution.
It has found protoplanetary disks, the birthing ground of stars.
It can detect gamma ray bursts.
In 1994 it took pictures of the comet Shoemaker Levy 9 striking Jupiter.
In 1995 the famous pillars of creation photo was taken of Eagle nebula.
In 1996 we saw the immense universe and the possibilities of galaxies in the millions.
In 2001 Hubble detected the first remains of an exoplanet in our atmosphere.
In 2005 it discovered two unknown moons orbiting Pluto.
To date four servicing missions have taken place in 1993, 1997, 1999/2002 (3a +3b) and 2009.
Hubble is open to the astronomy world; any astronomer can request time with the telescope and then after one year of studying the data, it is released to the community. This allows everyone to share the discoveries Hubble is continuing to make.
