{
 "source": "https://peabody.kids/flashcards/space-moons-sun-earth",
 "id": "space-moons-sun-earth",
 "title": "Moons, the Sun and Earth in Space",
 "category": "science",
 "subject": "Space",
 "levels": [
  "k-2",
  "3-5",
  "6-8"
 ],
 "description": "Famous moons, moon phases, eclipses and the Sun-Earth-Moon system.",
 "tags": [
  "moon",
  "sun",
  "eclipse"
 ],
 "frontLabel": "Question",
 "backLabel": "Answer",
 "cards": [
  [
   "How many natural satellites does Earth have?",
   "One, the Moon"
  ],
  [
   "How long does the Moon take to orbit Earth?",
   "About 27 days; phases repeat about every 29.5 days"
  ],
  [
   "Phases of the Moon",
   "The changing shapes of the lit part of the Moon we see"
  ],
  [
   "New moon",
   "The Moon is not visible because its lit side faces away"
  ],
  [
   "Waxing crescent",
   "A growing sliver of the Moon"
  ],
  [
   "First quarter",
   "Half the Moon is lit, the right half in the Northern Hemisphere"
  ],
  [
   "Waxing gibbous",
   "More than half lit and growing"
  ],
  [
   "Full moon",
   "The whole face of the Moon is lit"
  ],
  [
   "Waning gibbous",
   "More than half lit and shrinking"
  ],
  [
   "Third (last) quarter",
   "Half the Moon is lit, the left half in the Northern Hemisphere"
  ],
  [
   "Waning crescent",
   "A shrinking sliver of the Moon"
  ],
  [
   "Why does the Moon have phases?",
   "We see different amounts of its sunlit half as it orbits Earth"
  ],
  [
   "Does the Moon make its own light?",
   "No; it reflects sunlight"
  ],
  [
   "Lunar eclipse",
   "Earth's shadow falls on the Moon"
  ],
  [
   "Solar eclipse",
   "The Moon passes between the Sun and Earth, blocking sunlight"
  ],
  [
   "Total solar eclipse",
   "The Moon completely covers the Sun's disk"
  ],
  [
   "Is it safe to look at a solar eclipse without eye protection?",
   "No; use special eclipse glasses"
  ],
  [
   "Corona",
   "The Sun's outer atmosphere, seen during a total eclipse"
  ],
  [
   "Craters on the Moon come from",
   "Impacts of asteroids and meteoroids"
  ],
  [
   "Maria (lunar seas)",
   "Dark, flat plains of ancient lava on the Moon"
  ],
  [
   "Who first walked on the Moon?",
   "Neil Armstrong in 1969"
  ],
  [
   "Which mission landed first humans on the Moon?",
   "Apollo 11"
  ],
  [
   "How many Apollo missions landed people on the Moon?",
   "Six"
  ],
  [
   "Gravity on the Moon compared to Earth",
   "About one-sixth"
  ],
  [
   "Why does the same side of the Moon always face Earth?",
   "It rotates once for each orbit (tidal locking)"
  ],
  [
   "Moon landing year of the last Apollo mission",
   "1972, Apollo 17"
  ],
  [
   "Largest moon in the solar system",
   "Ganymede, a moon of Jupiter"
  ],
  [
   "Galilean moons",
   "Io, Europa, Ganymede and Callisto, found by Galileo in 1610"
  ],
  [
   "Io",
   "A volcanic moon of Jupiter"
  ],
  [
   "Europa",
   "An icy moon of Jupiter with an ocean beneath its ice"
  ],
  [
   "Titan",
   "Saturn's largest moon, with a thick atmosphere and lakes of methane"
  ],
  [
   "Enceladus",
   "A small icy moon of Saturn that sprays water ice from its south pole"
  ],
  [
   "Phobos and Deimos",
   "The two small moons of Mars"
  ],
  [
   "Triton",
   "Neptune's largest moon, which orbits backward"
  ],
  [
   "Charon",
   "The largest moon of Pluto"
  ],
  [
   "Miranda",
   "A moon of Uranus with cliffs and grooves"
  ],
  [
   "Titania",
   "The largest moon of Uranus"
  ],
  [
   "Callisto",
   "A heavily cratered moon of Jupiter"
  ],
  [
   "Mimas",
   "A small icy Saturn moon with one huge crater"
  ],
  [
   "Sun",
   "A star made mostly of hydrogen and helium"
  ],
  [
   "Sun's age, about",
   "4.6 billion years"
  ],
  [
   "Sun's surface temperature, about",
   "5,500 degrees Celsius"
  ],
  [
   "Sun's core temperature, about",
   "15 million degrees Celsius"
  ],
  [
   "What powers the Sun?",
   "Nuclear fusion of hydrogen into helium"
  ],
  [
   "How long does sunlight take to reach Earth?",
   "About 8 minutes"
  ],
  [
   "Sunspot",
   "A cooler, darker area on the Sun's surface"
  ],
  [
   "Solar flare",
   "A sudden burst of energy from the Sun"
  ],
  [
   "Solar wind",
   "A stream of charged particles flowing from the Sun"
  ],
  [
   "Aurora",
   "Glowing lights in the sky from solar particles hitting the atmosphere"
  ],
  [
   "Photosphere",
   "The visible surface of the Sun"
  ],
  [
   "Solar system formed from",
   "A cloud of gas and dust about 4.6 billion years ago"
  ],
  [
   "Earth's rotation period",
   "About 24 hours"
  ],
  [
   "Earth's orbit period",
   "About 365.25 days"
  ],
  [
   "Leap year",
   "A year with an extra day, February 29, to fix the calendar"
  ],
  [
   "Why do we have day and night?",
   "Earth rotates on its axis"
  ],
  [
   "Summer in the Northern Hemisphere happens when",
   "The Northern Hemisphere tilts toward the Sun"
  ],
  [
   "Satellite",
   "An object that orbits a planet"
  ],
  [
   "Tidal force",
   "The Moon's gravity tugging on Earth's oceans"
  ],
  [
   "Supermoon",
   "A full moon at its closest point to Earth, looking larger"
  ],
  [
   "Blue moon",
   "The second full moon in one calendar month"
  ],
  [
   "Harvest moon",
   "The full moon nearest the autumn equinox"
  ]
 ]
}