astronomy

Palomar Planet-Crossing Asteroid Survey

Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey rather than just read about it. In short: The Palomar Planet-Crossing Asteroid Survey (PCAS) was an astronomical survey, initiated by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S Palomar Observatory, California, in 1973. The program is responsible for the discovery of 95 near-Earth Objects including 17 comets, while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor planets during 1993–1994.

Key takeaways

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

Reference excerpt

The Palomar Planet-Crossing Asteroid Survey (PCAS) was an astronomical survey, initiated by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S Palomar Observatory, California, in 1973. The program is responsible for the discovery of 95 near-Earth Objects including 17 comets, while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor planets during 1993–1994. PCAS ran for nearly 25 years until June 1995. It had an international extension, INAS, and was the immediate predecessor of the outstandingly successful NEAT program.

Notable discoveries The first NEO discovered by PACS was (5496) 1973 NA, an Apollo asteroid with an exceptional orbital inclination of 68°, the most highly inclined minor planet known until 1999. In 1976, Eleanor Helin discovered 2062 Aten, the first of a new class of asteroids called the Aten asteroids with small orbits that are never far from Earth's orbit. As a result, these objects have a particularly high probability of colliding with the Earth. In 1979, Helin discovered an Apollo-type asteroid, that they later identified with the comet 4015 Wilson–Harrington. It was the first confirmation that a comet can evolve into an asteroid after it has degassed.

List of discovered minor planets

See also Brian P. Roman List of minor planet discoverers § Discovering dedicated institutions Spacewatch List of near-Earth object observation projects

References

Publications Helin, E.F.; Shoemaker, E.M. (December 1979). "The Palomar planet-crossing asteroid survey, 1973–1978". Icarus. 40 (3): 321–328. Bibcode:1979Icar...40..321H. doi:10.1016/0019-1035(79)90021-6. Helin, E. F. (1991). "Palomar Planet-Crossing Asteroid Survey (PCAS): Recent discovery rate". Asteroids, Comets, Meteors: 235–236. Bibcode:1992acm..proc..235H.

Worked examples

Example 1 — a first encounter with Palomar Planet-Crossing Asteroid Survey

Start with the simplest possible case. Write down what Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey

In research: Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey 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: Palomar Planet-Crossing Asteroid Survey is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1973 in science, Asteroid surveys, Astronomical discoveries by institution, so understanding it makes those chapters shorter.
In everyday life: Look for Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Palomar Planet-Crossing Asteroid Survey in simple terms?

Why does Palomar Planet-Crossing Asteroid Survey 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 Palomar Planet-Crossing Asteroid Survey?

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 Palomar Planet-Crossing Asteroid Survey.