Big Bang Theory
This theory describes why we observe the universe expanding.
What is the Big Bang Theory?
A galaxy is a collection of star systems and gas held together by this.
What is gravity?
This is a huge sphere of plasma gas that radiates light because of its high temperature.
What is a star?
Our star system is called this.
What is the solar system?
This is the distance light travels in a year.
What is a light-year?
This Catholic priest first proposed the Big Bang Theory.
Who is Georges Lemaitre?
Scientists estimate there are this many galaxies in the universe.
What are billions?
The color of a star depends on this.
What is temperature?
The solar system is described as this, meaning everything orbits or revolves around the Sun.
What is heliocentric?
This is the curved path that an object takes around another object.
What is an orbit?
Scientists estimate that the Big Bang occurred about this many years ago.
What is 13.8 billion years?
These are the three main types of galaxies.
What are spiral, elliptical, and irregular galaxies?
The Sun is an example of this type of object.
What is a star?
Our solar system revolves around this at the center of the Milky Way.
What is the galactic core?
These objects can be natural or artificial and orbit another object.
What are satellites?
This evidence for the Big Bang Theory allows scientists to observe energy created during the Big Bang.
What is the Cosmic Microwave Background (CMB)?
This is the name of our galaxy.
What is the Milky Way?
The Sun is approximately this far from Earth.
What is 93 million miles?
People once thought the solar system was this, meaning everything orbited Earth.
What is geocentric?
What is the difference between a natural and artificial satellite?
One is man-made and the other is not.
Because we can see objects this far away, we can see the universe as it was many years ago.
What are light-years?
This type of galaxy has spiral “arms.”
What is a spiral galaxy?
Light from the Sun takes about this long to reach Earth.
What is 8 minutes?
The solar system is about this many light-years from the center of the Milky Way.
What is 26,000 light-years?
Name at least three types of satellites.
Any man-made or natural three.