astronomy

Praxidike (moon)

Praxidike (moon) 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 Praxidike (moon) rather than just read about it. In short: Praxidike , also known as Jupiter XXVII, is a small retrograde irregular satellite of Jupiter. Discovery and Naming It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S.

Key takeaways

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

Reference excerpt

Praxidike , also known as Jupiter XXVII, is a small retrograde irregular satellite of Jupiter.

Discovery and Naming It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard in 2000, and given the temporary designation S/2000 J 7. It was named in August 2003 after Praxidike, the Greek goddess of punishment.

Orbit

Praxidike orbits Jupiter at an average distance of 21,147,000 km in 609.25 days, at an inclination of 149° to the ecliptic, in a retrograde direction and with an eccentricity of 0.230. Its orbit is continuously changing due to solar and planetary perturbations. It belongs to the Ananke group, made up a tightly of irregular retrograde moons orbiting Jupiter at a distance ranging between 19–22 million km, inclinations between 144 and 156°, and eccentricities between 0.10 and 0.30.

Physical characteristics With a diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself. Based on infrared heat measurements taken by the WISE space telescope, Praxidike's albedo was measured at 2.9%, making it one of the least reflective bodies in our solar system. The satellite appears grey (colour indices B−V=0.77, R–V= 0.34), typical of C-type asteroids.

Origin Praxidike probably did not form near Jupiter but was captured by Jupiter later. Like the other members of the Ananke group, which have similar orbits, it is probably the remnant of a broken, captured heliocentric asteroid.

References

Ephemeris IAU-MPC NSES Mean orbital parameters NASA JPL

External links David Jewitt pages Scott Sheppard pages

Illustrations

Praxidike (moon): Praxidike observed by the WISE spacecraft in 2010 — Praxidike observed by the WISE spacecraft in 2010

Worked examples

Example 1 — a first encounter with Praxidike (moon)

Start with the simplest possible case. Write down what Praxidike (moon) 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 Praxidike (moon) 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 Praxidike (moon) 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 Praxidike (moon)

In research: Praxidike (moon) 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 Praxidike (moon) 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: Praxidike (moon) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ananke group, Astronomical objects discovered in 2000, Discoveries by Scott S. Sheppard, so understanding it makes those chapters shorter.
In everyday life: Look for Praxidike (moon) 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Praxidike (moon)” →

Affiliate

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

How to study Praxidike (moon) in 20 minutes

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

Frequently asked questions

What is Praxidike (moon) in simple terms?

Praxidike , also known as Jupiter XXVII, is a small retrograde irregular satellite of Jupiter. Discovery and Naming It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S.

Why does Praxidike (moon) 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 Praxidike (moon)?

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 Praxidike (moon).