Basic Astronomy Flashcards
How many stars are in the Milky Way
100-400 Billion (or more) (Sources: Astronomy Answer Book and NASA)
Why do stars twinkle?
Turbulence in the atmosphere of the Earth. “As the atmosphere churns, the light from the star is refracted in different directions.” (Dave Kornreich, Astronomy at Cornell University)
What are emission nebulae
birthplace of stars. Coalescing gas and dust, often with a high proportion of large, hot, blue or white stars
How hot is our sun
10,000 degrees F.
5,778 degrees Kelvin
5,505 degrees Celsius
What is the order of planets in our solar system?
My Very Enormous Mouse Just Sat Upon Neptune
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
What can you see astronomically with binoculars
Craters on the moon
Jupiter’s moons
Open star clusters
Globular star clusters
Other galaxies (Andromeda!)
Phases of Venus
How many stars are you looking at in a truly dark place?
2500-5000 (astronomers don’t agree) (source: Earthsky.org)
How long is the precession cycle? What happens?
26,000 years. Earth’s northern axis is “wobbling” in a massive circle, pointing out a succession of pole stars
What is the speed of light
186,000 miles per second
What are M numbers
Charles Messier (1730-1817) - French comet hunter, listed “fuzzy” non-comet objects to avoid confusion in his search. List of 110 objects.
What are the names of the four Galilean moons
Io, Europa, Ganymede, Callisto
Why do stars shine?
Nuclear fusion - breaking down atoms at center. Hydrogen is being converted to Helium, releasing energy
Mars-How big and how far
Second smallest planet in our solar system. Half the diameter of Earth.
Distance varies, average 140 million miles (225 million km) from Earth. About 150 days travel with current tech in 2016ish
How far away are the stars
Alpha and proxima centauri, the nearest star system, are 4.3 LY away.
How far away is the Sun (one AU)
93 million miles (150 million kilometers)
What is the Light Year?
The distance light can travel in a year. About 6 trillion miles. if you scale the AU to one inch, then a light-year on that scale is about one mile.
