Astronomy Quiz #1

Lectures 1-6

Foucault Pendulum

Lab apparatus that proved that the Earth rotates

Centrifugal force

Outward force the Earth exerts strongest on the equator and nothing upon the poles.

Nuclear Fusion

Stars glow due to ___________ - reaction where 2 or more atomic nuclei combine to form one or more atomic nuclei (neutrons)

4 criteria of a planet

No nuclear fusion

Orbits a star

Large enough to be round

Has cleared its orbital path

Cosmic address

You, Earth, Solar System, Milky Way, Local Group, Local Cluster, Universe

Difference between local group and local cluster

Local cluster contains more galaxies

Nebula

A large cloud of gas existing around one or more stars that are found at the beginning and the end of star evolution

AU

Average distance from the Earth and the Sun (1.5 × 10^8 km)

Light year

The dist. light travels in one year (9.5 × 10^12km). Think about how we see things from far away in the past due to this phenomenon.

When we see a galaxy from x _______ away, we’re seeing what that galxy looked like x years ago.

Ecliptic

The plane that the Earth and other stars orbit the Sun to infinity

Earth’s angle of rotation

23.5 degrees (creates the seasons)

Magnitude

Unit of brightness of celestial objects in celestial sphere - the lower the number, the brighter the object

Physical size times 360 degrees/2pi times distance

Angular size (degrees) equation

Flipped

The moon looks ____ between the two hemispheres due to the curvature of the Earth.

Lunar month

Time it takes the Moon to finish orbiting the Earth - 29.5 days (same amount of time for it to complete one rotation - sycnhronous rotation).

Full, New

The Moon must be in the ___ moon phase during a Lunar Eclipse and ___ moon phase during a Solar Eclipse

2 conditions for an eclipse

Right phase

Moon must lie near Earth’s ecliptic plane to block or be blocked

Precession

The axis of the Earth, the 23.5 degree angle, traces the shape of a circle. In 26,000 years, the hemispheres will be flipped so that Summer in the Northern Hemisphere occurs in December and Summer in the Southern Hemisphere occurs in June.

Retrograde motion

Due to size of orbits between planets, from Earth’s perspective, planets further from the Sun look like they’re going backwards in their orbits. In reality, Earth is just speeding past the other planets in its orbit.

Equinox

Time of the season where the N. and S. hemispheres receive the same amount of sunlight.

Law of Ellipses: Planets revolve around the Sun in elliptical orbits

Law of Equal Areas: Planets move faster near the Perihelion than the Aphelion

Law of Periods: Distant planets have longer periods around the Sun

p²=a³

Kepler’s 3 laws + the period equation

The object will move at constant velocity until a net force acts upon it (planets tend to move in a straight line, but the centripetal force of the Sun moves it back into orbit)

F = ma

Every action has an equal and opposite reaction

Newton’s laws of motion

e=mc² where c = 3 × 10^8 m/s

Mass energy formula

m x g x h

Gravitational potential energy

Fg = G m1m2/d²

Universal law of gravitation

6.67 × 10^-11 m³/kgs²

Value of big G

Sq. root of 2GM/R

Vescape equation

p²= 4pi²a³/G(m1+m2)

Common Center of Mass Equation