astronomy

One-Mile Telescope

One-Mile Telescope is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand One-Mile Telescope rather than just read about it. In short: The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), Cambridge, UK is an array of radio telescopes (two fixed and one moveable, fully steerable 60 ft-diameter (18 m) parabolic reflectors operating simultaneously at 1407 MHz and 408 MHz) designed to perform aperture synthesis interferometry. History The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge University in 1964.

Key takeaways

One-Mile Telescope belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect One-Mile Telescope to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of One-Mile Telescope from memory before moving on to harder problems.

Reference excerpt

The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), Cambridge, UK is an array of radio telescopes (two fixed and one moveable, fully steerable 60 ft-diameter (18 m) parabolic reflectors operating simultaneously at 1407 MHz and 408 MHz) designed to perform aperture synthesis interferometry.

History The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge University in 1964. The telescope was used to produce the 5C catalogue of radio sources. Observations with larger incremental spacings were used to observe individual radio sources with unprecedented sensitivity, angular resolution, and image quality. These surveys required intensive use of inverse Fourier transforms, and were made possible by development of a new generation of computers such as the Titan. In 1971, Sir Martin Ryle described why, in the late 1950s, radio astronomers at MRAO decided on the construction of the new One Mile telescope: "Our object was twofold. First we wanted to extend the range of our observations far back in time to the earliest days of the Universe, and this required a large increase in both sensitivity and resolution. With greater resolution we hoped that we might be able to draw radio maps of individual radio sources with sufficient detail to give some indication of the physical processes which brought them into being." One of the One Mile Telescope dishes was temporarily used to improve the resolution of MERLIN (then MTRLI) from 1987 until Autumn 1990.

Technical innovations The One-Mile Telescope was the first telescope to use Earth-rotation aperture synthesis (described by Ryle as "super-synthesis") and the first to give radio maps with a resolution better than that of the human eye. The telescope was made up of three 120 ton dishes, each of which is 18 m in diameter. Two of the dishes are fixed, while the third can be moved along an 800 m-long (half mile) rail track, at speeds of up to 6.4 km/h. There were 60 different stations along the track, which is straight to within 0.9 cm, and whose far end was raised by 5 cm to allow for the curvature of the Earth over its length. The observing frequencies were usually 408 MHz (75 cm; the resolution was 80 arcsec) and 1.4 GHz (21 cm; the resolution was 20 arcsec, three times better than that of the unaided eye).

Notable achievements Over a 20-year career, the telescope was used to map individual objects, and to do several deep field surveys. Though still occasionally used, it is now essentially retired (one of the dishes is occasionally used for undergraduate projects or by amateur radio astronomers). The construction of this telescope and development of the Earth-rotation aperture synthesis used when operating it contributed to Martin Ryle and Antony Hewish receiving the Nobel Prize for Physics in 1974.

References

External links Media related to One-Mile Telescope at Wikimedia Commons Two antennae of the One-Mile Telescope on Google Maps

Illustrations

Worked examples

Example 1 — a first encounter with One-Mile Telescope

Start with the simplest possible case. Write down what One-Mile Telescope claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to One-Mile Telescope before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about One-Mile Telescope ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of One-Mile Telescope

In research: One-Mile Telescope appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses One-Mile Telescope in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: One-Mile Telescope is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cavendish Laboratory, Interferometric telescopes, Radio telescopes, so understanding it makes those chapters shorter.
In everyday life: Look for One-Mile Telescope outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “One-Mile Telescope” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study One-Mile Telescope in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what One-Mile Telescope means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain One-Mile Telescope out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is One-Mile Telescope in simple terms?

Why does One-Mile Telescope matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study One-Mile Telescope?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on One-Mile Telescope.