An object that orbits the Sun but is too small to be considered a planet.
What is an asteroid?
100
Reactions which combine light elements such as hydrogen into heavier elements such as helium, releasing energy.
What is nuclear fusion?
100
A huge group of stars, dust, gas and other objects bound together by gravitational forces.
What is a galaxy?
100
The distance between objects also affects this. The closer objects are to each other, the stronger this is between them. The farther apart, the weaker it is.
What is gravitational force?
200
9,460,000,000,000km or 9.46 ×10^12 km
What is a light year?
200
The distance from Earth to the sun, often used as a unit of measure for large distances.
What is astronomical unit?
200
Size, temperature, color and brightness.
What is star classification?
200
Spiral, barred, elliptical, lenticular and irregular.
What are galaxy shapes?
200
Astronomers use this type of study to determine what elements are present in stars.
What is spectroscopy?
300
The time until our sun becomes a red giant.
What is 4 billion years?
300
These are caused by the 23-degree tilt of the Earth's axis of rotation relative to its orbit.
What are seasons?
300
Gravitational forces cause denser regions of the nebula to collapse forming this?
What is a protostar?
300
A group of 30 galaxies including the Milky Way, the Large Magellanic Cloud, the Small Magellanic Cloud and the Andromeda galaxy.
What is the local group?
300
A spectacular explosion that is brighter than 10 billion stars and can outshine an entire galaxy for a few seconds.
What is a supernova?
400
The longest and most stable part of a star's life.
What is a star in the main sequence stage of its life cycle?
400
As a comet approaches the sun, some of its ice turns into gas and dust, which forms an outer layer called this.
What is a coma or visible tail?
400
This will occur during the red giant phase of our sun.
What is the incineration of Earth and all of the inner planets?
400
An object with such strong gravity that its escape velocity equals or exceeds the speed of light.
What is a black hole?
400
The faster the source of light is moving away from the observer the greater this is.
What is redshift?
500
The sun sits about 26,000 light years from the center of this.
What is the Milky Way?
500
According to this, inertia causes objects to tend to keep moving in a straight line.
What is Newton's first law?
500
A system with two stars that are gravitationally tied and orbit each other.
What is a binary star?
500
If this is known, then the inverse square law can be used to find the distance between galaxies.
What is the lumonsity of a star?
500
The universe exploded outward from a single point smaller than an atom into the vast expanse of galaxies and space we see today.