Epoch (astronomy)

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/epoch-astronomy

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the scientific category?Temporal reference point in astronomy and celestial mechanics
2. What is the common standard epoch?J2000.0 (January 1, 2000, 12:00 Terrestrial Time)
3. What is an epoch in astronomy?An epoch is a special moment in time that astronomers use as a reference point to describe where stars and planets are.
4. Why do astronomers use epochs?It gives a stable anchor so we can measure how objects change over time and predict their future positions.

Celestial Mechanics: The branch of astronomy that deals with the motion of celestial bodies under the influence of gravity.
Orbital Elements: A set of six parameters that uniquely define the shape, size, and orientation of an orbit.
Ephemeris: A table or data file giving the calculated positions and velocities of celestial objects at specified times.
Perturbations: Deviations from an ideal orbit caused by the gravitational forces of other celestial bodies.