![]() ![]() You can also use two of the stars in the “cup" of the Big Dipper to locate Polaris, the North Star. In the summer sky, it's usually not too difficult to find, though, as its unique ladle shape is easy to learn and spot. Like all groups of stars, the position of the Big Dipper changes throughout the year. The Big Dipper, also sometimes called the Plough, is made up of the seven brightest stars within Ursa Major. The Big Dipper, although sometimes referred to as a constellation, is actually an asterism.Īn asterism is an interesting pattern of stars within a larger constellation. Yet, when viewed from Earth's night sky, they appear to be close together and form some sort of pattern.įor example, one of the most popular and easily- identifiable constellations is called Ursa Major, which means “The Great Bear." Ursa Major is easy to identify because of seven of the stars within the constellation known as the Big Dipper. The stars within a constellation can be incredible distances apart. Most constellations have a long history and were identified hundreds, if not thousands, of years ago. You might also enjoy picking out constellations.Ĭonstellations are groups of stars in the sky that have been defined by and agreed upon by an international group of astronomers. ![]() These are the kinds of questions it's fun to WONDER about as you gaze at the stars. About 14,000 years ago, the celestial pole pointed toward the bright star Vega, and as it sweeps out its slow circle, it will again point to Vega in about 12,000 years.A warm evening…a blanket…a dark sky full of bright stars…these are the pieces of a perfect night for stargazing! Do you like to look up at the stars and WONDER about what's up there? Are there aliens? What is life like on other planets? How many stars are there? Sometimes there's no bright star near the celestial pole, as is the case in the Southern Hemisphere at present. This causes the celestial pole to wander in a slow circle over the eons, sweeping past different stars. Earth's axis of rotation wobbles over the course of about 26,000 years, the way a spinning top also wobbles as it spins. One other note about the North Star is that it's a title that passes to different stars over time. Polaris has not always been the North Star Observers there can use other clever ways to find due south, including using the stars of the Southern Cross constellation to point the way. The Southern Hemisphere doesn't have a bright star that marks the south celestial pole. Once you're facing toward Polaris, you know you're facing north, which can help you orient yourself any evening you're out stargazing. They point to Polaris, which is the tail of the Little Dipper (the constellation Ursa Minor). Locate Polaris using the two "pointer stars" on the end of the Big Dipper's cup. The two stars on the end of the Dipper's "cup" point the way to Polaris, which is the tip of the handle of the Little Dipper, or the tail of the little bear in the constellation Ursa Minor. Locating Polaris is easy on any clear night. It would appear directly overhead if you stood at the north pole, but farther south, it indicated the direction of north. ![]() So Polaris always stays in roughly the same place in the sky, and therefore it's a reliable way to find the direction of north. Because it's so close to the celestial pole, it traces out a very small circle over 24 hours. ![]() Some stars travel a great distance over the course of the night. The farther a star is from the pole, the larger the circle it travels around the sky. Over the hours, these stars each sweep out a circle around the celestial pole. As our planet rotates through the night, the stars around the pole appear to rotate around the sky. Polaris is located quite close to the point in the sky where the north rotational axis points – a spot called the north celestial pole. Earth rotates around this line, like a spinning top. This is the imaginary line that extends through the planet and out of the north and south poles. Polaris, known as the North Star, sits more or less directly above Earth's north pole along our planet's rotational axis. Polaris appears very close to the spot in the sky where Earth's axis of rotation points. ![]()
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