What is in a solar system?
Sun, planets, moons, asteroids, and comets.
What is our place in the universe?
We live on earth, in the milky in the observable universe
Local Supercluster
A mass concentration of galaxies
Local Group
The galaxy group that includes the Milky Way
What causes eclipses?
Sometimes when the Moon orbits Earth, the Moon moves between the Sun and Earth.
Speed of Light (actual speed in km/s)
300,000 km/s
Why did the ancient Greeks reject the real explanation for planetary motion?
Their inability to observe stellar parallax was a major factor.
What does the universe look like from Earth?
Black nothingness with some dots
Galaxy
an island of stars in space, held together by gravity and orbiting a common center
AU -
Earth's average distance from the sun
How does the orientation of Earth’s axis change with time?
It remains at 23.5 degrees but will change because of earths precession
What causes the seasons?
Earth’s precession
Why do we see phases of the Moon?
As the Moon orbits the Earth, the portion of illuminated Moon that we see changes
Planet
A celestial body that is orbiting a star
Kepler's Third Law
More distant planets orbit the Sun at slower average speeds, obeying the relationship
Why was planetary motion so hard to explain?
Because of the difference in force and gravity, the movement is inconsistent
How do galaxies move within the universe?
Galaxies rotate around their centers with the sections of the galaxy that are farther out from the galaxy's center rotating more slowly than the material closer to the center
How big is the universe
93 billion light years in diameter
Dwarf planet
A small celestial body that is orbiting the sun
Why do the constellations we see depend on latitude and time of year?
Earth's orbit changes the apparent location of the Sun among the stars.
How is Earth moving through Space?
the Earth rotates on its axis, hurtling us through space at nearly 1700 km/hr
Why do stars rise and set?
The earth's rotation makes an illusion that makes it seem like the stars are the ones moving
How did we come to be? (evolution)
We evolved from neanderthals
Galaxy Cluster
is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity
How do our lifetimes compare to the age of the universe?
A human lifetime is a fraction of a second compared to universal time