The Lovell Telescope is a Radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. The Lovell Telescope was constructed in the mid 1950s. The Lovell telescope was the largest steerable dish radio telescope in the world at 76.2 m (250 ft) in diameter when it was built. The Lovell telescope 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. The telescope was renamed to the Lovell Telescope in 1987 after Bernard Lovell, and became a Grade I listed building in 1988. The ovell telescope forms part of the Merlin and VLBI arrays of radio telescopes.
The 76m Lovell Telescope.
|Organization:||Jodrell Bank Observatory.|
2º18'25.74?W Coordinates: 53º14'13.2?N, 2º18'25.74?W
|wavelength:||Up to ~5GHz|
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 from as far away as the Pennines, Winter Hill, Snowdonia and the Peak District. It can also be seen from the terminal 1 restaurant area and departure lounges of Manchester Airport.
In September 2006, the telescope won the BBC's online competition to find the UK's greatest 'Unsung Landmark'.
Conception and construction of the Mark I Lovell Telescope.
In the late 1940s, Bernard Lovell built the Transit Telescope at Jodrell Bank. This was a 218ft-diameter telescope that 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. Although the Transit Telescope had been designed and constructed by astronomers, a fully-steerable telescope would need to be professionally designed and constructed; the first challenge was to find an engineer willing to do the job. This turned out to be Charles Husband, whom Lovell first met 8 September 1949.
Husband presented the first drawings of proposed giant, fully-steerable radio telescope in 1950. These plans were detailed in a "Blue Book", which was presented to the DSIR on 20 March 1951; the proposal was approved in March 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. 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.
Its two main altitude rotator bearings are 15-inch gun turret bearings from the World War II battleships HMS Revenge and Royal Sovereign. These were purchased in 1950; the telescope was designed around them. It has an Altazimuth mount, which was originally controlled by a purpose-built analogue computer.
Construction began on 3 September 1952. The foundations for the telescope took until 21 May 1953 to be completed. Due to the accuracy required with the double railway lines, it then took until Mid-March 1954 to get these completed. The central pivot was delivered to the site on 11 May 1954, and the final bogie in mid-April 1955.
In February 1954, Lovell and the Air Ministry met to see if funding could be made available for improving the accuracy of the dish so that it could be used on centimeter wavelengths, for research at these wavelengths for the Ministry as well as "other purposes". Although the funding was not ultimately made available from the Air Ministry, this improvement was made anyway as the planning process had already progressed too far.
The telescope moved for the first time on 3 February 1957: by an inch! It was first moved azimuthally under power on 12 June 1957; the bowl was tilted under power for the first time on 20 June 1957. By the end of July the dish surface was completed, and first light was on 2 August 1957; the telescope did a drift scan across the Milky Way at 160MHz, with the bowl at the zenith. The telescope was first controlled from the control room on 9 October 1957.
There were large cost overruns with the telescope's construction, mostly due to the steeply rising cost of steel at the time the telescope was constructed, amongst other factors. The original grant for the telescope's construction came jointly from the Nuffield Foundation and the government; this amounted to £335,000. The government increased its share of the funding several times as the cost of the telescope rose; other money came from private donations. The final part of the debt from the construction of the telescope, £50,000, was paid off by Lord Nuffield and the Nuffield Foundation on 25 May 1960 (partly due to the telescope's early, very public role in space probe tracking; see below), and Jodrell Bank observatory was renamed to the Nuffield Radio Astronomy Laboratories. The final total cost for the telescope was £700,000.
Statistics of the Lovell Telescope.
|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|
Space probe tracking by the Lovell Telescope.
The telescope became operational in the summer of 1957, just in time for the launch of Sputnik 1, the world's first artificial satellite. The telescope was the only one in the world able to track Sputnik's booster rocket by radar; it first located it just before midnight on 12 October 1957. It also located Sputnik 2's carrier rocket at just after midnight on 16 November 1957.
The telescope has been used to track a number of other space probes, including:
In more recent years, it has also searched for several lost Mars spacecraft, including NASA's Mars Observer spacecraft in 1993, Mars Polar Lander in 2000 and the Beagle 2 lander on Mars in 2003. However, it did not succeed in locating any of them.
Lovell Telescope interferometry.
The early investigation into the size and nature of quasars drove the development of interferometry techniques in the 1950s; the Lovell telescope had an advantage due to its large collecting area, meaning that high sensitivity interferometer measurements can be made relatively quickly using it.
Interferometry at Jodrell Bank started before the Lovell telescope was constructed, using the Transit Telescope with another, smaller telescope. These experiments continued, using the Lovell telescope in place of the Transit Telescope, once construction of the Lovell telescope was complete.
The telescope took part in the first transatlantic interferometer experiment in 1968, with other telescopes being those at Algonquin and Penticton in Canada.
In 1980, it was used as part of the new Merlin array.
Lovell Telescope general scientific use.
In April 1961, a radar echo from Venus was achieved using the telescope while the planet was at a close approach, confirming measurements of the distance of the planet made by American telescopes.
In 1968, the telescope observed the coordinates of the recently-discovered pulsar, confirming its existence and investigating the dispersion measure. It was also used to make the first detection of polarization of the pulsar's radiation. This marked the start of a substantial amount of work investigating pulsars at Jodrell, which is still ongoing.
Between 1972 and 1973, the telescope was used for "a detailed survey of the radio sources in a limited area of the sky ... up to the sensitivity limit of the instrument". Among the objects catalogued was the first gravitational lens, which was confirmed optically in 1979. The telescope was also involved in the detection of the first Einstein ring in 1998, in conjunction with observations made with the Hubble Space Telescope.
The telescope was used as a follow-up instrument for possible SETI detections made at Arecibo between 1998 and the end of 2003. No signals were detected.
In February 2005, astronomers using the Lovell Telescope discovered a Galaxy that appears to be made almost entirely of Dark matter.
Lovell Telescope ICMB watchdog.
Between April 1962 and September 1963, the telescope was on standby for "Project Verify" (also known by the codewords "Lothario" and "Changlin"). during strategic alerts, a 'pulse transmitter, receiver and display equipment' could be connected to the telescope to scan known Russian launch sites for indications of launches of ICBMs and/or IRBMs.
During the Cuban Missile Crisis in October 1962, the telescope was discretely turned towards the iron curtain to provide a few minute's warning of any missiles that might have been launched then.
Upgrade to Mark IA Lovell Telescope.
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.copes"
Later upgrades and repairs to the Lovell Telescope.
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.
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.
The Lovell Telescope in popular culture.
Books about the Lovell Telescope.