A
This is the number of how many solar systems are in our universe
What is billions
The 3rd planet in our solar system that orbits the sun
What is the planet Earth
Built many instruments that accurately studied and measured the locations of planets and stars
Who is Tycho Brahe
The force of gravity acting on an object that changes depending on where you are in the universe
What is weight
This can tell astronomers about the star's temperature
What is luminosity
This astronomer calculated that planet's orbited the sun in an ellipse
This is the shape that is made when the eccentricity becomes one
What is a straight line
The force by which all things with mass or energy, including planets, stars, and galaxies are brought toward one another
What is gravity
Was the first star to be correctly measured in distance by astronomers
What is the north star
The sun makes up this percentage of the mass in our solar system
What is 95%
During this season in New York, the sun is the largest
What is winter
This planet has the shortest orbital period since it is closest to the sun
What is Mercury
When the shadow of the Earth can be seen on the moon
What is a lunar eclipse
These 2 planets of the solar system do not have moons
What is Mercury and Venus
During this season in New York, the sun is the smallest
What is summer
1 astronomical unit is equal to this many miles
What is 93 million
The first measurement of the Earth's Circumference
What is 40,000 km
In this year, Copernicus published his work stating the sun was at the center of the solar system
What is 1543
Eccentricity always falls between these 2 numbers
What is 0 and 1
The formula to easily solve for eccentricity
What is E = d / L
Astronomer who explained retrograde motion by saying that the planets moved along smaller circles, which in turn moved along orbits around Earth
Who is Ptolemy