AstroFacts for May 2011
May 31: Each of Uranus’ 27 moons are named after either a William Shakespeare and Alexander Pope character.
May 30: A Venusian day (243 Earth days) is longer than a Venusian year (225 Earth days).
May 29: At birth, 75% of a star is hydrogen and 25% helium, with only traces of other elements.
May 28: A galactic year (about 225 million years) is the time it takes our Solar System to make one complete trip around the Galaxy.
May 27: If our Sun were instantly replaced by the red hypergiant star VY Canis Majoris only Uranus and Neptune would be outside the star.
May 26: Saturn’s moon Titan has more oil and natural gas than all known reserves on Earth.
May 25: The more craters you find on the surface of a solar system object, the older its surface must be.
May 24: Contrary to intuition, the bigger the star the shorter its lifetime.
May 23: Although Uranus is barely visible to the naked eye, it took the use of telescopes to recognize it as a planet.
May 22: Although astronomers call them white dwarfs, depending on their surface temperatures, they can look blue, white, yellow, or red.
May 20: The estimated number of stars in the observable Universe is 100,000,000,000,000,000,000,000. That’s 100 sextillion.
May 19: In 1054 AD the Chinese recorded the Crab supernova, but the actual supernova occurred 6500 years earlier.
May 18: The Moon rotates at the same rate as it orbits the Earth. This is why the same side of the Moon is always facing the Earth.
May 17: On a clear night about 3,000 stars are visible to the naked eye. There are roughly 100,000,000,000 stars in our Galaxy alone.
May 16: Polaris currently holds the North Star title, but given thousands of years other select stars will take over this title.
May 15: Of the 8 planets, 6 are named after Roman gods. Uranus is a Greek god and Earth derives from Old English and Germanic.
May 14: At 9980 °F (5800 K) the Earth’s core is about the same temperature as the Sun’s surface.
May 13: Our Sun is big, but it only takes about 110 Earth diameters to make up the diameter of the Sun.
May 12: During fusion reactions of the sort that power the Sun, the Sun’s total mass decreases ever so slightly.
May 11: There’s no permanently dark side to the Moon, but because a lunar day is a month long, nighttime last for about two weeks.
May 10: Although Saturn is the one planet we think of as having rings, all four of the outer planets have rings.