Astronomy Midterm

What is the distance light travels in one year called?

Light-year.

How is 500,000,000 expressed in scientific notation?

5 x 10^8.

What is the relationship of distance to light travel time for a star that is 100 light-years away?

It takes 100 years for the light from that star to reach Earth.

What do Astronomers study in the Cosmic Microwave Background (CMB)?

Patterns in CMB light to determine the contents of the universe and the origins of galaxies.

What is the definition of eccentricity in astronomy?

A measure of the deviation of the orbit of a celestial body from a perfect circle.

What is the escape velocity formula?

V_escape = √(2GM/R), where M is the mass of the planet and R is its radius.

What are Kepler's three laws related to?

The motion of planets orbiting the Sun.

What is the equation for Kepler's third law?

P^2 = a^3, where P is the period in years and a is the semimajor axis in astronomical units.

What happens during a solar eclipse?

The moon gets in between the Sun and the Earth.

What is the electromagnetic spectrum?

The range of all types of electromagnetic radiation.

What is the significance of the Doppler Effect in astronomy?

It indicates the change in frequency of a wave in relation to an observer moving relative to the source.

What do CCDs do in astronomical instruments?

They capture images digitally as semiconductor devices organized into pixels.

What is blackbody radiation?

The relationship between an object's temperature and the wavelength of electromagnetic radiation it emits.

What is the speed of light in meters per second?

C = 3 x 10^8 m/s.

What defines the obliquity of Earth?

The angle of Earth's axis tilted in relation to its orbital plane.

What is the meaning of redshift and blueshift?

Redshift occurs when an object moves away, and blueshift occurs when it moves toward the observer.