40 Questions, 1 point each. There is a button at the bottom of the page to tally your total score.

1. Just after New Moon, we can faintly see the part of the Moon that is still in shadow. What famous person is the first one known to recognize that this is from "earthshine" (sunlight reflected off the Earth, to the Moon, and back)?	Isaac Newton Galileo Galilee Leonardo da Vinci Hint    Reset    Cheat
2. When there are two full moons in the same calendar month the second one is called a "Blue Moon." How often does this event happen on average?	Every 2 1/2 to 3 years Every 3 1/2 to 5 years Every 5 1/2 to 10 years Hint    Reset    Cheat
3. What is the name of the most prominent crater on the Moon?	Tycho Copericus Kepler Hint    Reset    Cheat
4. In 1609 Galileo discovered four moons orbiting Jupiter. Three of them are named "Io", "Ganymede" and "Callisto." What did he name the other one?	Vesta Europa Amalthea Hint    Reset    Cheat
5. What color is on the outside of the arc of a rainbow?	Red Green Blue Hint    Reset    Cheat
6. How many (official) planets are in our solar system?	Ten Nine Eight Hint    Reset    Cheat
7. How many tails does a comet have as it approaches the Sun?	One Two Three Hint    Reset    Cheat
8. What did the Earth do in 1910 that caused unnecessary fear for many people around the world?	Nearly missed an asteroid. Reversed its magnetic poles. Passed through a comet tail. Hint    Reset    Cheat
9. What object is sometimes called the Evening Star and sometimes called the Morning Star?	Vega Virgo Venus Hint    Reset    Cheat
10. The Sun, Moon, and Planets move along a narrow path around the sky. What are the constellations along this path collectively called?	Zodiac Analemma Circumpolar Hint    Reset    Cheat
11. What is the closest star to Earth?	Alpha Centauri Proxima Centauri Sun Hint    Reset    Cheat
12. Ceres, Pallas, Juno, and Vesta are names for four of what type of objects?	Asteroids Moons Stars Hint    Reset    Cheat
13. What occurs when the Earth passes through the debris left behind by a passing comet?	Meteor shower Aurora Occultation Hint    Reset    Cheat
14. If the Earth were the size of a tennis ball, how big and how far away would the Sun be?	A basketball 12 miles away 24 feet across, 1/2 mile away 48 miles across, 126 miles away Hint    Reset    Cheat
15. In 1066 King Harold of England saw something in the sky and considered it a sign of bad luck. What was it?	Comet Halley Total solar eclipse Meteor shower Hint    Reset    Cheat
16. A large impact created the Chicxulub Crater on the Yucatan Peninsula. What other major event appears to coincide with this?	Formation of the Moon Global warming Extinction of the dinosaurs Hint    Reset    Cheat
17. William Herschel discovered the planet Uranus and his sister discovered eight comets. What is her first name?	Elizabeth Caroline Victoria Hint    Reset    Cheat
18. If our entire solar system could fit into a coffee cup, how big would our galaxy be (The Milky Way)?	Seattle Washington State North American Continent Hint    Reset    Cheat
19. Edmond Halley (for which the comet is named) studied tides and the Earth's magnetism. What was the name of his ship?	Englewood Black Amesbury Blue Paramour Pink Hint    Reset    Cheat
20. After the Sun and the planets, what is the largest body in the solar system?	Ganymede Pluto Earth's Moon Hint    Reset    Cheat
21. What causes sunspots to appear on the surface of the Sun?	An object crashes in. A burst of energy comes out. The magnetic field is distorted. Hint    Reset    Cheat
22. Why does Mars appear red?	Rust Ice Carbon Dioxide Hint    Reset    Cheat
23. Which two planets, as seen from Earth, go through phases like the Moon?	Venus and Mercury Venus and Mars Jupiter and Mars Hint    Reset    Cheat
24. What atmopheric effect can rarely be seen, and usually only for a second or two at the end of a sunset?	Gegenschein Green Flash Brocken Spectre Hint    Reset    Cheat
25. What is the name given by some to the full moon nearest the winter solstice?	Witch's Moon Hunter's Moon Harvest Moon Hint    Reset    Cheat
26. Which constellation does the Sun pass through, but is not part of the horoscope?	Orion Leo Minor Ophiuchus Hint    Reset    Cheat
27. What celestial objects are named after characters in Shakespeare plays?	Some near-Earth asteroids Some moons of Uranus Some craters on Mercury Hint    Reset    Cheat
28. Sometimes there is a ring around the Moon. What causes this?	Gravitational lensing Micrometeroidal particles Atmospheric ice crystals Hint    Reset    Cheat
29. On average, how often does Comet Halley come to the inner solar system?	126 years 3016 years 76 years Hint    Reset    Cheat
30. Who discovered Pluto?	Clyde Tombaugh Percival Lowell Tycho Brahe Hint    Reset    Cheat
31. What effect led Edwin Hubble to discover the expansion of the Universe?	Microwave Background Anisotropy Redshift Hint    Reset    Cheat
32. What is the primary cause of the seasons?	Tilt of Earth's axis Inclination of Earth's orbit Changing distance to the Sun Hint    Reset    Cheat
33. What is the Sun mostly made of?	Hydrogen Carbon Helium Hint    Reset    Cheat
34. What single factor determines a star's brightness, color, length of its life, and how it is to die?	Core temperature Total mass Volume Hint    Reset    Cheat
35. What comet hunter composed a list of the most famous objects outside our solar system?	Charles Messier Johannes Kepler Pierre Laplace Hint    Reset    Cheat
36. How many leap years are there in 400 years?	104 100 97 Hint    Reset    Cheat
37. Who figured out that the planets orbit in the shape of an ellipse instead of a circle?	Isaac Newton Johannes Kepler Edwin Hubble Hint    Reset    Cheat
38. The HR Diagram compares a star's temperature to what?	Size Mass Luminosity Hint    Reset    Cheat
39. What process caused the Moon to always present the same side towards Earth?	Plate Tectonics Lunar Libration Tides Hint    Reset    Cheat
40. The precise position of the Sun at noon each day changes over a period of a year, describing a "figure 8" in the sky. What is this called?	The Analemma Precession of the Equinox Solar Constant Hint    Reset    Cheat