Lovell Telescope
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| Lovell Telescope | |
 The 76m Lovell Telescope |
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| Organization: | Jodrell Bank Observatory |
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| Location: | Cheshire, UK |
| Wavelength: | Up to ~5GHz |
| Built: | 1952–1957 |
| Diameter: | 250ft, 76.2m |
| Collecting area: | 5270m2 |
| Mounting: | Alt-azimuth |
The Lovell Telescope is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When it was constructed in the mid 1950s, the telescope was the largest steerable dish radio telescope in the world at 76.2 m (250 ft) in diameter. It was originally known as the 250-ft telescope or the Radio Telescope at Jodrell Bank, before becoming the Mark I telescope around 1961 when future telescopes (the Mark II, III and IV) were being discussed. [1] It was renamed to the Lovell Telescope in 1987 after Bernard Lovell. It became a Grade I listed building in 1988. The telescope forms part of the MERLIN and VLBI arrays of radio telescopes.
If the air is clear enough, the Mark I telescope can be seen from high-rise buildings such as the Beetham Tower in Manchester and as far as the Pennines, Winter Hill, Snowdonia and the Peak District, and more easily from the terminal 1 restaurant area and departure lounges of Manchester Airport.
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[edit] History
In the late 1940s, Bernard Lovell built the Transit Telescope. This 218ft-diameter telescope could only look directly upwards; the next logical step was to build a telescope that could look at all parts of the sky, so that more sources could be observed, as well as for longer integration times.
Charles Husband presented the first drawings of proposed giant, fully-steerable radio telescope in 1950. The plans were detailed in a "Blue Book", which was presented to the DSIR in 1951; the proposal was approved in Spring 1952. The telescope was originally going to have a wire mesh surface to observe long wavelengths; this was changed to a steel surface when the 21cm hydrogen line was discovered in 1951, so that it could be observed with the Lovell telescope.[2] Additionally, it was constructed so that the bowl could be completely inverted, with the aim of using a movable tower located at the base of the telescope to change the receivers at the focus.[3]
Its two main altitude rotator bearings are 15-inch gun turret bearings from the World War II battleships HMS Revenge and Royal Sovereign.[3] It has an Altazimuth mount, which was originally controlled by a purpose-built analogue computer. [2]
Construction began in 1952; it became operational in the summer of 1957, just in time for the launch of Sputnik 1, the world's first artificial satellite. Jodrell Bank was the only installation in the world able to track Sputnik's booster rocket by radar. The telescope was also used to track the Pioneer 1 rocket.[3] As a result, Lord Nuffield paid off the remaining debt on the Mark I in 1960, and Jodrell Bank observatory was renamed to the Nuffield Radio Astronomy Laboratories.
In 1969, the Mark I was used for the first time in a VLBI observation.
At the time of its construction in 1957, the telescope was only expected to have an operational lifespan of 10 years. By the late 1960s, this was starting to be demonstrated as the telescope decayed. It was therefore repaired and upgraded to become the Mark IA. Phase 1 of the upgrade added an inner track in September 1968 to February 1969. Phase 2 (September-October 1969) relaid the railway track, which had been decaying and sinking over the previous years; added four bogies on the inner track and their steelwork, and overhauled the existing bogies on the outer track. Upthrust units for the inner bogies were ordered during Phase 2, but not fitted until 1970. Phase 3 (August 1970-November 1971) saw the addition of a new bowl surface in front of the old surface; fatigue cracks in the cones connecting the bowl to the towers were repaired; the central antenna was strengthened, and the central "bicycle wheel" support was added, as well as a new computer control system. [1][4]
In January 1976, storms brought winds of around 90 mph which almost destroyed the telescope. One of the bearings connecting the dish to the towers slipped. After an expensive repair, bracing girders were added to prevent this happening again. [4]
In 1980, it was used as part of the new MERLIN array.
By the 1990s, the telescope surface was becoming badly corroded. In 2001-2003, the telescope was resurfaced, increasing its sensitivity at 5 GHz by a factor of five. A new drive system was installed, which provides a much higher pointing accuracy. The outer track was also relaid and the focal tower was strengthened.[5]
In September 2006, the telescope won the BBC's online competition to find the UK's greatest 'Unsung Landmark'. [6]
[edit] Scientific results
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In 1962, as part of a radio-linked interferometer with the Mark II telescope, the Mark I identified a new class of compact radio sources, later recognised as quasars.
In 1968, the telescope was used to confirm the existence of pulsars.
The first gravitational lens was discovered by the Mark IA in 1979.
The telescope began participation with the SETI project in 1998.
In February 2005, astronomers using the Lovell Telescope discovered a galaxy that appears to be made almost entirely of dark matter.
The telescope has been used to track a number of space probes, including:
- Sputnik 1's booster rocket in 1957[3]
- Pioneer 1 in 1958[3]
- Luna 2 in 1959, the first spacecraft to hit the moon [3]
- Luna 3 also in 1959 [3]
- It sent commands and received data from the Pioneer 5 probe in 1960. It was the only telescope in the world capable of doing so at the time. [3]
- The USSR unmanned moon lander Luna 9 in February 1966, the first spacecraft to make a soft landing on the Moon, and listened in on its facsimile transmission of photographs from the moon's surface. The photos were sent to the British press and published before the Soviets themselves had made the photos public.
It has also searched for several lost spacecraft, including NASA's Mars Observer spacecraft in 1993 and the Beagle 2 lander on Mars in 2003.
[edit] Statistics
| Location: | Lat./Long. |
| Mass of telescope: | 3200 t |
| Mass of bowl: | 1500 t |
| Diameter of bowl: | 76.2 m = 250 feet |
| Surface area of bowl: | 5270 m² = 1.3 acres |
| Collecting area of bowl: | 4560 m² = 1.127 acres |
| Height of elevation axis: | 50.5 m = 165.68 feet |
| Maximum height above ground: | 89.0 m = 292 feet |
| Radius of wheel girders: | 38.5 m = 126.31 feet |
| Outer diameter of railway track: | 107.5 m = 352.690 feet |
| Amount of paint for 3 coats of the bowl: | 5200 L |
[edit] Popular culture
- In 1962, the telescope was mentioned in a sci-fi novel A for Andromeda, by Fred Hoyle and John Elliot.
- In 2000, Placebo recorded the video for 'The Bitter End' in the bowl of the Lovell Telescope.
[edit] References
- ^ a b Lovell, Bernard (1985). The Jodrell Bank Telescopes. Oxford University Press. ISBN 0-19-858178-5.
- ^ a b The 250ft Mk I Radio Telescope - The building of the worlds' first giant radio telescope.. Jodrell Bank Observatory. Retrieved on 2006-11-23.
- ^ a b c d e f g h Lovell, Bernard (1968). The Story of Jodrell Bank. Oxford University Press.
- ^ a b The MKIA Radio Telescope. Jodrell Bank Observatory. Retrieved on 2006-11-21.
- ^ The Lovell Telescope Upgrade. Jodrell Bank Observatory. Retrieved on 2006-11-23.
- ^ Finlo Rohrer. "Aye to the telescope", BBC News, 5 September 2006.
[edit] External links
- Jodrell Bank Observatory - official site.
- The Blue Book
- "Radio telescope makes space history", BBC News, March 14, 1960.
