Galaxies
Milky Way
States the entire universe was once confined to a dense, hot, supermassive ball. Then, about 13.7 billion years ago, a violent explosion occurred, hurling this material in all directions
Big Bang Theory
The way the Earth rotates
counterclockwise
December 21st, at which the northern hemisphere has its minimum daylight hours
June 21st, at which the northern hemisphere has its maximum daylight hours
Summer solstice
the burning of a fuel and oxidant to produce heat
Combustion
type of spiral galaxy with a bar of stars that runs through its center
barred spiral galaxy
the theory that describes how stars and planets form from contracting, spinning disks of gas and dust
Solar Nebular Theory
Earth's tilt in degrees
The Earth rotates on an axis tilted at 23.5 degrees
Each of the two times of the year when days and nights are of equal length
Equinox
All of the frequencies or wavelengths of electromagnetic radiation
Electromagnetic spectrum
a galaxy with arms that curve outward in a pinwheel pattern with a bright center of stars
Spiral galaxy
Planets orbit the sun in a path called an ellipse
Kepler's First Law of Planetary Motion
Effects of Earth's rotation
1. day and night
2. equatorial bulge
3. Coriolis effect
March 20th or 21st in the northern hemisphere, place where the sun crosses the celestial equator moving northward
Spring (vernal) equinox
a reaction in which two small nuclei join to form a single large nucleus; the source of power for the sun and other stars.
Nuclear fusion
A galaxy shaped like a round or flattened ball, generally containing only old stars; no arms
Elliptical galaxy
Planets move faster when they are close to the sun and slower when they are further away. They "sweep out" equal areas in equal time intervals.
Kepler's Second Law of Planetary Motion
The changing direction of Earth's axis, but without any change in tilt
Precession
September 21st or 22nd in the northern hemisphere
-Change in the direction of the axis of the Earth, but without any change in tilt
Fall (Autumnal) Equinox
The sun mostly emits these 3 types of light
ultraviolet (UV), visible light, and infrared (IR)
A galaxy that has an undefined shape and pattern; large numbers of spread out young stars and greats amounts of gas and dust are usually found near larger galaxies
Irregular Galaxy
The farther away a planet orbits, the longer the planet takes to revolve around the sun
What is Kepler's Third Law of Planetary Motion?
Wobbling around the precessional axis
Nutation
The season in which the hemisphere that leans closer to sun receives more sunlight
Summer
In order of increasing wavelength, decreasing frequency on the electromagnetic spectrum
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves