ArticleslgStudy

astronomy

Mills Cross Array

Mills Cross Array 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 Mills Cross Array rather than just read about it. In short: The Mills Cross Array, or the 96-acre antenna array, was a Mills Cross Telescope-style radio telescope located in Seneca Maryland, near Washington, D.C. Constructed in June, 1954, it was operated by the Carnegie Institution of Washington.

Key takeaways

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

Reference excerpt

The Mills Cross Array, or the 96-acre antenna array, was a Mills Cross Telescope-style radio telescope located in Seneca Maryland, near Washington, D.C. Constructed in June, 1954, it was operated by the Carnegie Institution of Washington. The full array consisted of two arms, each 2047 feet in length with 66 dipole antennas. The dipole antennas were supported by unpainted wooden poles, connected with wires. The telescope had around 5 miles (8.0 km) of wire, with an army surplus truck housing the phase-switching radio receiver. It was built to conduct a 22.2 MHz (13.5 meter) sky survey, and at that frequency it had a beam about 2.5 degrees wide. In 1955 the array was used by Bernard F. Burke and Kenneth Franklin to discover 22.2 MHz radio emission from Jupiter, which they tentatively attributed to thunderstorm-like activity in Jupiter's atmosphere. Although radio waves had been detected from astronomical sources as early as 1931, this was the first detection of radio waves from another planet. The field where the array was located is now part of the McKee-Beshers Wildlife Management Area.

References

Worked examples

Example 1 — a first encounter with Mills Cross Array

Start with the simplest possible case. Write down what Mills Cross Array 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 Mills Cross Array 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 Mills Cross Array 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 Mills Cross Array

In research
Mills Cross Array 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 Mills Cross Array 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
Mills Cross Array is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical observatory stubs, Radio telescopes, so understanding it makes those chapters shorter.
In everyday life
Look for Mills Cross Array 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.

Affiliate

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

How to study Mills Cross Array in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Mills Cross Array means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Mills Cross Array out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mills Cross Array in simple terms?

The Mills Cross Array, or the 96-acre antenna array, was a Mills Cross Telescope-style radio telescope located in Seneca Maryland, near Washington, D.C. Constructed in June, 1954, it was operated by the Carnegie Institution of Washington.

Why does Mills Cross Array 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 Mills Cross Array?

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 Mills Cross Array.

Tags

  • Astronomical observatory stubs
  • Radio telescopes

Keep exploring