Our Solar System
In our Solar System, this planet is the only that has water in the liquid state.
What is Earth?
These are dark areas on the our local star's surface.
What are sunspots?
At the center of most galaxies is this object
What are black holes?
It's gravity is so powerful that not even light can escape it.
What is a black hole?
This force starts the creation of stars and galaxies
What is gravity?
This a dwarf planet, takes this 248 years to orbit the son.
What is Pluto?
This is the celestial cloud where stars and galaxies are born
What is a nebula?
These galaxies are composed of mostly old stars
What is an elliptical galaxy?
This is the size of a city but has the mass equal to our Sun's.
What is a neutron star?
When this spins it forms into the shape of a disk
What is a Spiral galaxy?
The hottest stars tend to be one of these two colors
What are blue and white?
This their "arms" can be tighty wrapped around it's center.
What is a spiral galaxy?
This event creates black holes and neutron stars
What is a Supernova?
In this process, the nuclei of atoms fuse together to form a larger nucleus.
What is nuclear fusion?
Because of it's canal-like scars, people used to think this planet was populated
What is Mars?
This event creates black holes and neutron stars
What is a Supernova
This is the name of the closest major spiral galaxy to us
What is the Andromeda Galaxy?
This is created by the death of a small star.
What is a white dwarf star?
The distance, in miles, of an A.U.
What is 93,000,000 miles
This is the 8th planet from the Sun, has a surface made of mostly hydrogen, helium, and methane gas.
What is Neptune?
This is the stage of a star when it has stabilized.
What is the main-sequence. [of a star's life]
Galaxies are born here
Nebula Cloud
the boundary around a black hole where gravity becomes so strong that light can't escape it.
What is an event horizon?
How long it takes the Sun to complete a galactic year
230 million years [within 20 million years is acceptable]