astronomy

Transit of minor planets

Transit of minor planets 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 Transit of minor planets rather than just read about it. In short: A transit of a minor planet takes place when a minor planet passes directly between an observer and another heavenly body, obscuring a small part of that body's disc. From the perspective of observers on Earth, transits of the Sun and Moon by minor planets are very rare, as the minor planets orbiting between the Earth and those bodies are few and very small.

Key takeaways

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

Reference excerpt

A transit of a minor planet takes place when a minor planet passes directly between an observer and another heavenly body, obscuring a small part of that body's disc. From the perspective of observers on Earth, transits of the Sun and Moon by minor planets are very rare, as the minor planets orbiting between the Earth and those bodies are few and very small. Transits of the Sun would be more visible from the outer planets. Transits should be distinguished from occultations, in which the minor planet entirely blocks out the light from the other body.

Asteroids Most asteroids orbit in the asteroid belt between Mars and Jupiter. For this reason, transits of the Sun by asteroids are rare from Earth's perspective, but would not be uncommon from the perspective of Jupiter. Still, the high inclination of many asteroid orbits would make this less common that it would be otherwise. One example of a forthcoming asteroid transit visible from Jupiter will be that of 4 Vesta, which will transit the Sun on January 4, 2044, with an angular diameter of 0.24″. From the perspective of Earth, the only types of asteroids that can transit the Sun are those with orbits that take them between the two bodies. These include Aten asteroids (including Apohele asteroids and the hypothetical Vulcanoid asteroids) and some Apollo asteroids (perhaps including quasi-satellites of Earth). Unfortunately, observations of such transits are difficult because all of these asteroids are only a few kilometres in diameter at most, so that their angular diameter is too tiny to observe against the Sun. One example was the May 16, 1990 transit of 3838 Epona with a diameter of 2.5 km. At a distance of 0.53 AU (79,000,000 km) from Earth, its angular diameter was only 0.007 seconds of arc, far too small to see. Similarly, asteroid 30825 (1990 TG1) transited on April 14, 2005, but was again unobservable, having an angular diameter of about 0.05″, and 2101 Adonis transited on September 24, 2007, with an even smaller angular diameter of only 0.005″. In theory, if a transit took place during a very close approach by a near-Earth asteroid, it might be observable. However, no such asteroid transits have been observed up to the present time.

Comets Comets may also transit the Sun; for example, Halley's Comet transited on 19 May 1910. Another example was C/1819 N1, the Great Comet of 1819, but occurrence of that transit was not known until after it had happened, when the orbit was calculated, and although some observers later claimed to have seen the comet transiting the Sun at the time, these observations seem dubious.

Transits of the moon It is theoretically possible that minor planets on an Earth-crossing orbit could transit the Moon. However, such events would be extremely rare since only a few catalogued minor planets, such as 2004 FH, have come closer to Earth than the distance of the Moon. Such an event might be observable (an asteroid of 25 metres' diameter at a distance of 380,000 km has an angular diameter of 0.01″), but none has been observed as yet, although there have been some reports of such events, sometimes classified as UFO-sightings.

See also Transit of Mercury Transit of Venus Great Comet of 1819

References

Martin Hoffmann, Asteroid transits over the disk of the Sun, Minor Planet Bulletin 16 (1989), 16 [1] (1989MPBu...16...11H)

External links JPL Horizons (useful for calculating positions of solar system objects) TRANSIT OF VENUS 2012: Live Webcast(Multipoint)- by SWAN-India

Worked examples

Example 1 — a first encounter with Transit of minor planets

Start with the simplest possible case. Write down what Transit of minor planets 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 Transit of minor planets 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 Transit of minor planets 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 Transit of minor planets

In research: Transit of minor planets 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 Transit of minor planets 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: Transit of minor planets is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical transits, so understanding it makes those chapters shorter.
In everyday life: Look for Transit of minor planets 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 Transit of minor planets in 20 minutes

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

Frequently asked questions

What is Transit of minor planets in simple terms?

Why does Transit of minor planets 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 Transit of minor planets?

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 Transit of minor planets.