#separator:tab #html:false #tags column:4 How many natural satellites does Earth have? One, the Moon space-moons-sun-earth How long does the Moon take to orbit Earth? About 27 days; phases repeat about every 29.5 days space-moons-sun-earth Phases of the Moon The changing shapes of the lit part of the Moon we see space-moons-sun-earth New moon The Moon is not visible because its lit side faces away space-moons-sun-earth Waxing crescent A growing sliver of the Moon space-moons-sun-earth First quarter Half the Moon is lit, the right half in the Northern Hemisphere space-moons-sun-earth Waxing gibbous More than half lit and growing space-moons-sun-earth Full moon The whole face of the Moon is lit space-moons-sun-earth Waning gibbous More than half lit and shrinking space-moons-sun-earth Third (last) quarter Half the Moon is lit, the left half in the Northern Hemisphere space-moons-sun-earth Waning crescent A shrinking sliver of the Moon space-moons-sun-earth Why does the Moon have phases? We see different amounts of its sunlit half as it orbits Earth space-moons-sun-earth Does the Moon make its own light? No; it reflects sunlight space-moons-sun-earth Lunar eclipse Earth's shadow falls on the Moon space-moons-sun-earth Solar eclipse The Moon passes between the Sun and Earth, blocking sunlight space-moons-sun-earth Total solar eclipse The Moon completely covers the Sun's disk space-moons-sun-earth Is it safe to look at a solar eclipse without eye protection? No; use special eclipse glasses space-moons-sun-earth Corona The Sun's outer atmosphere, seen during a total eclipse space-moons-sun-earth Craters on the Moon come from Impacts of asteroids and meteoroids space-moons-sun-earth Maria (lunar seas) Dark, flat plains of ancient lava on the Moon space-moons-sun-earth Who first walked on the Moon? Neil Armstrong in 1969 space-moons-sun-earth Which mission landed first humans on the Moon? Apollo 11 space-moons-sun-earth How many Apollo missions landed people on the Moon? Six space-moons-sun-earth Gravity on the Moon compared to Earth About one-sixth space-moons-sun-earth Why does the same side of the Moon always face Earth? It rotates once for each orbit (tidal locking) space-moons-sun-earth Moon landing year of the last Apollo mission 1972, Apollo 17 space-moons-sun-earth Largest moon in the solar system Ganymede, a moon of Jupiter space-moons-sun-earth Galilean moons Io, Europa, Ganymede and Callisto, found by Galileo in 1610 space-moons-sun-earth Io A volcanic moon of Jupiter space-moons-sun-earth Europa An icy moon of Jupiter with an ocean beneath its ice space-moons-sun-earth Titan Saturn's largest moon, with a thick atmosphere and lakes of methane space-moons-sun-earth Enceladus A small icy moon of Saturn that sprays water ice from its south pole space-moons-sun-earth Phobos and Deimos The two small moons of Mars space-moons-sun-earth Triton Neptune's largest moon, which orbits backward space-moons-sun-earth Charon The largest moon of Pluto space-moons-sun-earth Miranda A moon of Uranus with cliffs and grooves space-moons-sun-earth Titania The largest moon of Uranus space-moons-sun-earth Callisto A heavily cratered moon of Jupiter space-moons-sun-earth Mimas A small icy Saturn moon with one huge crater space-moons-sun-earth Sun A star made mostly of hydrogen and helium space-moons-sun-earth Sun's age, about 4.6 billion years space-moons-sun-earth Sun's surface temperature, about 5,500 degrees Celsius space-moons-sun-earth Sun's core temperature, about 15 million degrees Celsius space-moons-sun-earth What powers the Sun? Nuclear fusion of hydrogen into helium space-moons-sun-earth How long does sunlight take to reach Earth? About 8 minutes space-moons-sun-earth Sunspot A cooler, darker area on the Sun's surface space-moons-sun-earth Solar flare A sudden burst of energy from the Sun space-moons-sun-earth Solar wind A stream of charged particles flowing from the Sun space-moons-sun-earth Aurora Glowing lights in the sky from solar particles hitting the atmosphere space-moons-sun-earth Photosphere The visible surface of the Sun space-moons-sun-earth Solar system formed from A cloud of gas and dust about 4.6 billion years ago space-moons-sun-earth Earth's rotation period About 24 hours space-moons-sun-earth Earth's orbit period About 365.25 days space-moons-sun-earth Leap year A year with an extra day, February 29, to fix the calendar space-moons-sun-earth Why do we have day and night? Earth rotates on its axis space-moons-sun-earth Summer in the Northern Hemisphere happens when The Northern Hemisphere tilts toward the Sun space-moons-sun-earth Satellite An object that orbits a planet space-moons-sun-earth Tidal force The Moon's gravity tugging on Earth's oceans space-moons-sun-earth Supermoon A full moon at its closest point to Earth, looking larger space-moons-sun-earth Blue moon The second full moon in one calendar month space-moons-sun-earth Harvest moon The full moon nearest the autumn equinox space-moons-sun-earth