astronomy

Ridge A

Ridge A 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 Ridge A rather than just read about it. In short: Ridge A is a site in Antarctica that was identified in 2009 as the best suited location on the surface of Earth for astronomical research. The site, approximately 1,000 kilometres (620 mi) from the South Pole and 144 kilometres (89 mi) southeast of Dome A, is situated in a portion of Antarctica claimed by Australia in the Australian Antarctic Territory.

Key takeaways

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

Reference excerpt

Ridge A is a site in Antarctica that was identified in 2009 as the best suited location on the surface of Earth for astronomical research. The site, approximately 1,000 kilometres (620 mi) from the South Pole and 144 kilometres (89 mi) southeast of Dome A, is situated in a portion of Antarctica claimed by Australia in the Australian Antarctic Territory. The site is on the Antarctic Plateau at an altitude of 4,053 metres (13,297 ft), and has an average winter temperature of −70 °C (−94 °F). It is possible that this site may have even lower temperatures than Dome A, with temperatures that might reach as low as or even colder than the legendary mark of -100°C (-148°F). Ridge A was identified by a team of Australian and American scientists searching for the best observatory spot in the world. The team leader described the site as "so calm there's almost no wind or weather there at all." Ridge A is a low ridge of ice and has been estimated to have very low disturbances to visibility, such as thick atmospheric boundary layer, amount of water vapour and a number of others. The site represents the "Eye of the Storm", whereby winds flowing off Antarctica in all directions appear to start from a point at Ridge A, where winds are at their calmest. It is also the site of a vortex in which swirling stratospheric winds high up and calm air at ground level combine to make it a place for viewing into space that is three times clearer than any other location on Earth. Researchers on the project suggested that photographs taken through a telescope at Ridge A could be nearly as good as those taken by the Hubble Space Telescope. Despite the difficult conditions on Antarctica and the remote location of Ridge A, construction costs for an observatory there that could match the Hubble Space Telescope could be built at a fraction of the cost of sending Hubble into space. For several years, a second Giant Magellan Telescope in Antarctica has been proposed.

Observatory Since January 2012, a small international observatory, the High Elevation Antarctic Terahertz (HEAT) telescope, has operated at Ridge A, jointly run by American and Australian researchers. By virtue of the weather, this submillimetre or terahertz telescope is capable of observing wavelengths of light that rarely make it through the atmosphere to the ground anywhere else on Earth.

See also Dome A List of optical telescopes South Pole Telescope

References

Worked examples

Example 1 — a first encounter with Ridge A

Start with the simplest possible case. Write down what Ridge A 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 Ridge A 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 Ridge A 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 Ridge A

In research: Ridge A 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 Ridge A 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: Ridge A is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomy in the Antarctic, Extreme points of Earth, Proposed buildings and structures in Antarctica, so understanding it makes those chapters shorter.
In everyday life: Look for Ridge A 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.

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How to study Ridge A in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ridge A 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 Ridge A out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ridge A in simple terms?

Why does Ridge A 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 Ridge A?

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 Ridge A.