Planets orbit the sun in a shape known as an ________, which looks like a squished circle.
Ellipse
100
We are looking back in time when look at the stars because it takes such a long time for their _________ to travel to Earth.
Light
100
Constellations are used to __________________.
Divide the sky into sections or "states".
100
A _________ is a newly formed star; a _______ is a newly formed planet.
Protostar, protoplanet
100
The ________ of an object in space is how it spins on its axis; the _________ of an object in space is how it travels around another object.
Rotation, revolution
200
The incorrect idea held in ancient times that the Earth was the center of the solar system was called the _________ theory.
Geocentric
200
Astronomers use _______ to determine the distance from the Earth to a star.
Parallax
200
The _________ magnitude of a star is how bright it appears to be, while the _________ magnitude of a star is how bright the star actually is at a distance of 10 parsecs.
Apparent, absolute
200
A star spends the majority of its life in its _____________.
Main sequence
200
What term is used for the 12 (or 13) constellations that are along the ecliptic?
The zodiac
300
The constellations surrounding Polaris that are visible all year long are called the ________ constellations.
Circumpolar
300
A _________ is a huge explosion that a high-mass star undergoes after its super giant phase and before its final stage.
Supernova
300
Medium- to low-mass stars like our sun usually become ______ at the end of their lives.
White dwarves
300
During the Big Bang, _______ became _______.
Energy, matter
300
The point at which a planet is closest to the sun is called ___________, while the point at which a planet is farthest away from the sun is called _________.
Perihelion, aphelion
400
A solar system must have _______ and _______.
Planets, at least 1 star
400
A star gives off its own _______ and creates its own energy through _____________ (H + H = He).
Light, nuclear fusion
400
The _______ of a star is the distance from the star to the horizon; the zenith overhead has a value of ______ while the horizon has a value of _______.
Altitude, 0 degrees, 90 degrees
400
The Earth's north star will not always be ______ because of ________ as the Earth wobbles on its axis.
Polaris, precession
400
Declination tells the _______ of a star, while right ascension tells the _______ of a star.
Latitude, longitude
500
List all the planets in our solar system.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptue
500
The hottest stars in our universe are _______ in color, while the coolest stars are ________.
Blue, red
500
The _______ of a star describes its direction from North and is given as a value between _____ and _____.
Azimuth, 0 degrees, 360 degrees
500
Describe the first steps in the formation of a star using the following words:
nebula
gravity
protostar
A star forms within a nebula from dust and gases aggregating together. Gravity allows the dust and gas to form a protoplanet.
500
What are the two possible final stages of a high-mass star?