ASVAB CampAstronomy flashcards
8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.
Fact · 1/8
List the eight planets in order from the Sun.
Mercury, Venus, Earth, Mars (rocky terrestrial planets), then Jupiter, Saturn (gas giants), Uranus, Neptune (ice giants). Pluto is a dwarf planet in the Kuiper Belt, not a ninth planet.
Term · 2/8
Rotation versus revolution: what does each cause?
Rotation is Earth spinning on its axis about once a day, causing day and night. Revolution is Earth orbiting the Sun in about 365.25 days; together with axial tilt it produces the seasons.
Rule · 3/8
What is the Sun-Earth-Moon alignment for a solar eclipse versus a lunar eclipse?
Solar eclipse: Sun, Moon, Earth, at new moon; the Moon's shadow falls on Earth. Lunar eclipse: Sun, Earth, Moon, at full moon; Earth's shadow falls on the Moon. The Moon's 5 degree orbital tilt prevents monthly eclipses.
Common trap · 4/8
What causes the Moon's phases?
Seeing different fractions of the Moon's sunlit half as it orbits Earth (cycle about 29.5 days). Phases are not caused by Earth's shadow; that happens only in a lunar eclipse.
Term · 5/8
Meteoroid, meteor and meteorite: what is the difference?
A meteoroid is a small rock in space. A meteor is the bright streak it makes burning through the atmosphere. A meteorite is a piece that survives and lands on the ground.
Common trap · 6/8
Is a light-year a unit of time or distance?
Distance: how far light travels in one year, about 9.46 trillion km (light moves about 300,000 km/s). A star 6 light-years away is seen as it was 6 years ago.
Formula · 7/8
How long does sunlight take to reach Earth?
time = distance / speed = 150,000,000 km / 300,000 km/s = 500 s, about 8 minutes 20 seconds. The Earth-Sun distance of about 150 million km is 1 astronomical unit (AU).
Fact · 8/8
What does a star's color reveal, and how do Sun-like and massive stars end?
Blue-white stars are hotter than red stars. A Sun-like star becomes a red giant, then a white dwarf; a much more massive star can explode as a supernova, leaving a neutron star or black hole.