astronomy

Michael Efroimsky

Michael Efroimsky 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 Michael Efroimsky rather than just read about it. In short: Michael Efroimsky (Russian: Михаил Эфроимский) is an American astronomer of Russian origin. His research interests are in celestial mechanics and Planetary Science.

Key takeaways

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

Reference excerpt

Michael Efroimsky (Russian: Михаил Эфроимский) is an American astronomer of Russian origin. His research interests are in celestial mechanics and Planetary Science. He is working as a Research Scientist at the US Naval Observatory in Washington DC. Michael Efroimsky is a member of the International Astronomical Union and the American Astronomical Society (AAS). In 2008 - 2009, he served as the Chair of the Division on Dynamical Astronomy of the AAS. With Sergei Kopeikin and George Kaplan, Michael Efroimsky co-authored a book on the relativistic celestial mechanics of the Solar System. With Benoit Noyelles, Julien Frouard and Valeri V. Makarov, Michael Efroimsky co-authored a theory

explaining the origin of the present state of rotation of the planet Mercury, a so-called 3:2 spin-orbit resonance. With Amirhossein Bagheri, Amir Khan, and other colleagues, Michael Efroimsky co-authored a theory explaining the origin and orbital evolution of Phobos and Deimos, the satellites of Mars.

According to this theory, Phobos and Deimos are remnants of a common progenitor, a larger protomoon destroyed by a collision with a planetesimal. In 2024, Michael Efroimsky published a paper outlining the hypothesis to explain the unique shape of Mars. He suggested that the high triaxiality of this planet is due to a long-lost moon, which was synchronous, i.e., residing above the same point of the Martial equator. Efroimsky christened it Nerio.

He demonstrated that if Nerio were large enough, perhaps a third the mass of the Moon, its gravitational pull on the young and still soft Mars was sufficient to create an asymmetric tidal bulge, which later fossilised and made the equator noncircular, resulting in the planet's triaxial shape. Efroimsky also hypothesised that the tips of that bulge were more prone to subsequent volcanic and tectonic activity than the rest of the Martian surface, leading to the development of both Tharsis and the highlands on the side opposite to it. Michael Efroimsky also published translations from classical Russian poetry.

Notes

External links personal webpage

Worked examples

Example 1 — a first encounter with Michael Efroimsky

Start with the simplest possible case. Write down what Michael Efroimsky 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 Michael Efroimsky 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 Michael Efroimsky 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 Michael Efroimsky

In research: Michael Efroimsky 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 Michael Efroimsky 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: Michael Efroimsky is common in secondary-school and first-year university syllabi. It links to neighbouring topics American astronomers, American people of Russian descent, Living people, so understanding it makes those chapters shorter.
In everyday life: Look for Michael Efroimsky 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 Michael Efroimsky in 20 minutes

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

Frequently asked questions

What is Michael Efroimsky in simple terms?

Michael Efroimsky (Russian: Михаил Эфроимский) is an American astronomer of Russian origin. His research interests are in celestial mechanics and Planetary Science.

Why does Michael Efroimsky 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 Michael Efroimsky?

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 Michael Efroimsky.