20 of the best Hubble facts and photos
Trapped on this, metaphorically speaking, ever shrinking planet there is not one amongst us who has not stared up into the heavens and gazed in awe at the myriad of pin pricks that make up the night sky.
Enter stage left the telescope, a technological innovation of the most profound importance, without which we'd be left in the quagmire of astronomical ignorance.
There are many fine examples of this device, from the twin telescopes which make up the Gemini Observatory to the ultra-powerful Large Binocular Telescope (LBT) in Ariz with its twin 8.4-metre mirrors.
None, however, can claim to have caught the public's imagination in the same way as the Hubble Space Telescope, which during its 20 years of service has beamed some absolutely stunning pictures back to Earth thanks to the lack of atmospheric distortion, something that ground-based telescopes have to cope with.
So to celebrate the Hubble Space Telescope's 20th anniversary (24 April 2010) we thought we'd bring you some spectacular photos and interesting facts, which will hopefully give you a glimpse into its long and illustrious career.
How It Works
The Hubble is a telescope of the Cassegrain variety, which collects incoming light on its primary mirror. This light hits the primary mirror at the back then bounces off, and hits the concave secondary mirror which then fires the light back through a hole and onto the instruments.
Plenty Of Pics
More than 30,000 objects have come under the all seeing eye of the Hubble Space Telescope in its 20-year history.
Gas Pillars in the Eagle Nebula
Nebulae are thought to be the factories in which stars are formed as they consist of great clouds of space dust. This picture, coined the "Pillars of Creation", was taken in 1995. The step shape is caused by the Wide Field and Planetary Camera 2, which is made up of 4 different cameras. One of these cameras can take magnified photos, so in order to fit it has to be reduced in size.
What's In A Name?
The name of the now famous telescope takes after the brilliant American astronomer Edwin Hubble who, apart from demonstrating that the Universe consisted of more than one galaxy, through his work on the Doppler effect showed that the Universe was expanding - paving the way for the Big Bang theory.
Monocerotis light echo
V838 Monocerotis is a star in the constellation Monocerotis and the light echo, seen here, is caused by the initial outburst of light from the star reflecting off intervening interstellar dust. Pretty spectacular.
Not A Polished Start
After its launch on the 24 April 1990 it soon became clear that all was not well with the Hubble telescope, as images sent back were a little on the blurry side. It turns out that the highly polished surface of the mirror was suffering from a problem known as spherical aberration, something which affects the sharpness of an image when light rays reflect off the mirror's edge. The flaw was only very small, but when dealing with such huge distances it meant that it was enough to warrant a mission to put it right.
After 11 months of training the crew was sent up in 1993 where they spent 5 days repairing the telescope - the rest as they say is history.
Blackeye Galaxy M64
The Galaxy's bright nucleus is surrounded by dark interstellar dust, the contrast of which makes for a fantastic image. It can also be seen through small telescopes due to its low apparent magnitude (the measure of its brightness observed from Earth).
A Tasteful Glimpse
Like other man-made satellites, it is possible to see the Hubble telescope with the naked eye. Wait for a clear night away from any light pollution, and by using this handy Hubble tracker you might be able to spot as a bright, fast moving dot in the night sky.
Situated in the constellation of Taurus, the Crab Nebula was first observed in 1731 by John Bevis and is thought to be expanding at around 1500 km/s.
The Hubble Space Telescope transmits a large quantity of data every week (approx 120 gigabytes) so you'd soon fill up your iPhone, whilst the power required for it to perform its various operations comes from its two 25-foot solar panels, which charge 6 nickel-hydrogen (NiH) batteries.
This is an absolute stalwart of the Internet. Dubbed the Eye of God by many, it is a type of planetary nebula, which is formed when a very large and very hot star explodes.
Need For Speed
One thing which cannot be said about the Hubble Telescope is that it's slow. It can complete an orbit of the Earth in just 97 minutes at a speed of 17,500 mph at an altitude of 353 miles. Blink and you'll miss it.
The Sombrero Galaxy is situated in the constellation Virgo, though how much it resembles the iconic Mexican headgear is debatable. With an apparent magnitude of +9.0 it is visible with an average telescope and it's apparently a hit with professional astronomers.
Size Isn't Everything
Compared to a lot of ground-based telescopes Hubble is a bit on the small side. Its dimensions are 43.5ft (13.2m) in length, has a maximum diameter of 14ft (4.2m) and weighs in at around the 11-tonne mark (to give a little context a standard route master bus is 27.5ft or 8.4m in length). Although what it lacks in size it more than makes up for in price, as it cost the cool $1.5 billion at launch.
The Eta Carinae is visible as the bright area in the centre of the large bi-polar Homunculus Nebula. The stellar system contains multiple stars most of which are very bright, due the this their life is relatively short, and are expected to explode as a supernova or hypernova in the next million years.
Yes, despite the rather colourful images seen around the Web, the pictures taken by the Hubble Space Telescope are in fact in black and white. The electronic detectors record the light from the Universe in shades of black and white, the colour is then added later.
This is not to say that there is no scientific basis for the colouring, rather that it is used to enhance features of an object that we might otherwise miss and bring out subtle detail, as well as giving an indication of how the object would appear if our eyes were on a par with Hubble.
This ultra-clear image shows Saturn's Aurora, and like on Earth it is thought to be powered by the solar wind.
Age Of Discovery
The Hubble telescope has had a marked role to play in many discoveries, not least of which has been to strengthen the hypothesis that dark energy causes the expansion of the Universe to accelerate. It was also instrumental in narrowing down the estimated age of the Universe from 10 to 20 billion years to 13 to 14 billion, as well as giving astronomers detailed information on supernovae, and galaxies in various evolutionary states.
Central section of the Milky Way
This photograph is actually a combined effort between the Hubble, Compton Gamma Ray Observatory, Chandra X-ray Observatory and Spitzer Space Telescope and does a wonderful job of showing off our very own galaxy.
End Of An Era
All good things must come to an end and Hubble is no different as after April 2013 no more servicing missions are planned. Without the regular maintenance the telescope's main functions it will begin to fail until it spins out of orbit; its prolonged life means that it will outlast the space shuttle programme and so won't be able to be guided safely back to Earth. However, life also springs eternal, as the James Web Telescope is due for launch in 2014.
We hope you've enjoyed this brief jaunt into some of Hubble's facts and famous images, and credit has to be given to the fantastic Hubblesite.org, which has a whole host of info and images available and is well worth a visit.