A look into the past
The giant Telescope was carried into orbit in April 1990 and is a collaboration between NASA and the European Space Agency. The Hubble project was funded as far back as the 1970’s and was set to be launched in 1983 but unforeseen circumstances such as budget issues and the Challenger disaster (see Missions page) put the launch on hold. When finally launched in 1990, there was another major set-back. Technicians discovered that the telescope had trouble focusing and this was the result of the main mirror being ground incorrectly. The telescope would not be repaired until a servicing mission was launched in 1983.
There have been five servicing missions, the last occurring in May 2009. Servicing Mission 1 took place in December 1993 when Hubble’s imaging flaw was corrected. Servicing missions 2, 3A, and 3B repaired various sub-systems and replaced many of the observing instruments with more modern and capable versions. However, following the 2003 Columbia disaster, (see Missions page) the fifth servicing mission was canceled on safety grounds. The fifth and final servicing mission eventually launched in May 2009 which saw the installation of two new instruments. Testing of this new equipment meant that the telescope will remain off-line until September 2009. This new equipment should allow the Hubble to function until at least 2014 when the telescope is due to be taken out of service. The Hubble telescope is due to be replaced by the James Webb Space Telescope.
According to NASA, “Hubble played a key role in discovering that a mysterious form of energy called dark energy is acting like a cosmic gas pedal, accelerating the universe’s expansion rate. Dark energy shoves galaxies away from each other at ever-increasing speeds and works in opposition to gravity.” Hubble’s observations of supernovas helped reveal that the mysterious energy is a constant presence in the universe. (sourced from Nationalgeographic.com)
One of Hubble’s key duties was to help astronomers determine a precise age for the universe. The telescope helped astronomers accomplish that goal, narrowing the universe’s age to 13 to 14 billion years old, an accuracy of about 10 percent. Astronomers made observations of Cepheid variable stars, pulsating stars used to measure vast distances, in the Virgo and other clusters to establish the expansion rate and the universe’s age.
According to NASA, “Hubble provided astronomers with a ‘scrapbook’ full of snapshots of the early universe including pictures of the ‘deep’ universe in a series of unique observations: the Hubble Deep Fields, the Great Observatories Origins Deep Survey, and the Hubble Ultra Deep Field (pictured left). The observations provided the deepest views of the cosmos in visible, ultraviolet, and near-infrared light.” Astronomers using ground-based telescopes to hunt for planets outside our solar system, dubbed extra-solar planets, have nabbed more than a hundred alien worlds. But they needed the keen ‘eye’ of Hubble to make the first direct measurement of the chemical makeup of an extra solar-planet’s atmosphere.
The telescope detected the elements sodium, hydrogen, carbon, and oxygen in the atmosphere of a Jupiter-size planet. The unique observation demonstrates that Hubble and other telescopes can sample the chemical makeup of the atmospheres of alien worlds.” The Hubble Telescope also detected that the core of most galaxies contain a Black Hole which devours everything within its vicinity. These Black Holes are said to have a mass of millions to billions times that of our sun.
In order to take images of distant, faint objects, Hubble must be extremely steady and accurate. The telescope is able to lock onto a target without deviating more than 7/1000th of an arcsecond, or about the width of a human hair seen at a distance of 1 mile.
Looking Into The Past:
When we see images of distant galaxies captured by Hubble, we do not see them as they are today, but as they were millions of years ago. This is caused by the Speed of Light. The speed of light has been measured at 300,000 kilometers per second and distances in space are so vast that instead of using miles or kilometers to measure the distances between objects, astronomers use light years. A light year is the distance that light travels in one year. If something happens in a galaxy that is 1 million light years away, it would take 1 million years for people on Earth to witness it.
Collision of Galaxies
The image above, captured by the NASA/ESA Hubble Space Telescope, shows what happens when two galaxies become one. The twisted cosmic knot seen here is NGC 2623 — or Arp 243 — and is located about 250 million light-years away in the constellation of Cancer (The Crab).
NGC 2623 gained its unusual and distinctive shape as the result of a major collision and subsequent merger between two separate galaxies. This violent encounter caused clouds of gas within the two galaxies to become compressed and stirred up, in turn triggering a sharp spike of star formation.
This active star formation is marked by speckled patches of bright blue; these can be seen clustered both in the center and along the trails of dust and gas forming NGC 2623’s sweeping curves (known as tidal tails). These tails extend for roughly 50 000 light-years from end to end. Many young, hot, newborn stars form in bright stellar clusters — at least 170 such clusters are known to exist within NGC 2623.
Like firecrackers lighting up the sky on New Year’s Eve, the majestic spiral arms of NGC 5559 are alight with new stars being born. NGC 5559 is a spiral galaxy, with spiral arms filled with gas and dust sweeping out around the bright galactic bulge. These arms are a rich environment for star formation, dotted with a festive array of colors including the newborn stars glowing blue as a result of their immensely high temperatures.
NGC 5559 was discovered by astronomer William Herschel in 1785 and lies approximately 240 million light-years away in the northern constellation of Boötes (the herdsman).
In 2001, a calcium-rich supernova called 2001co was observed in NGC 5559. Calcium-rich supernovae are described as “fast-and-faint,” as they’re less luminous than other types of supernovae and also evolve more rapidly, to reveal spectra dominated by strong calcium lines. 2001co occurred within the disk of NGC 5559 near star-forming regions, but calcium-rich supernovae are often observed at large distances from the nearest galaxy, raising curious questions about their progenitors.
Credit: ESA/Hubble & NASA Text credit: European Space Agency
The Hubble Space Telescope captured what looks like a colorful holiday ornament in space. It’s actually an image of NGC 6326, a planetary nebula with glowing wisps of outpouring gas that are lit up by a central star nearing the end of its life.
When a star ages and the red giant phase of its life comes to an end, it starts to eject layers of gas from its surface leaving behind a hot and compact white dwarf. Sometimes this ejection results in elegantly symmetric patterns of glowing gas, but NGC 6326 is much less structured. This object is located in the constellation of Ara, the Altar, about 11,000 light-years from Earth.
Planetary nebulae are one of the main ways in which elements heavier than hydrogen and helium are dispersed into space after their creation in the hearts of stars. Eventually some of this out-flung material may form new stars and planets.
This picture was created from images taken using the Hubble Space Telescope’s Wide Field Planetary Camera 2. The vivid blue and red hues come from material including ionized oxygen and hydrogen glowing under the action of the fierce ultraviolet radiation from the still hot central star.
Credit: ESA/Hubble & NASA Text credit: European Space Agency
Hubble Telescope Facts:
- Named after American astronomer Edwin P Hubble (1889 – 1953).
- Launched in April 1990 from space shuttle Discovery.
- Mission duration = 20 years.
- Servicing mission 1: December 1993 (repaired the mirror).
- Servicing mission 2: February 1997.
- Servicing mission 3A: December 1999.
- Servicing mission 3B: February 2002.
- Servicing mission 5: May 2009 (which included the installation of new equipment).
- Size: Length 43.5 ft (13.2 m), Weight 11,110 kg (24,500 lb), Diameter 14 ft (4.2 m).
- Cost at launch = $1.5bn.
- Orbit: 353 miles or 569 km.
- Time to complete one orbit: 97 minutes.
- Speed: 17,500 mph (28,000 kph).