Earth orbits around the Sun once each year. Our view into space through the night sky changes as we orbit. So, the night sky looks slightly different each night because Earth is in a different spot in its orbit. The stars appear each night to move slightly west of where they were the night before. Your location on Earth also determines what stars and constellations you see, and how high they appear to rise in the sky. The Northern Hemisphere is always pointing in a different direction than the Southern Hemisphere.
This means that stargazers in Australia, for example, get a slightly different view of the sky and can see a few different constellations than those in the United States. It can be a little confusing to picture how the night sky changes as we orbit the Sun. You can see how it all works in the illustration below.
A chart showing some of the constellations that are visible from the Northern Hemisphere in different times of year. Want more? Our star finder activity is a great way to have some fun and learn about the constellations visible in our night sky each month. This image of the Orion nebula was captured by the Hubble Space Telescope. It is located in the constellation Orion, below the three stars that form the hunter's belt.
Astronomy is the scientific study of everything in outer space. Astronomers and other scientists study stars and galaxies, most of which are many light-years away from Earth. Studying the scientific properties of these objects in space helps us to understand how the universe was made, what else is out there, and how we fit in.
Astrology is not the same thing as astronomy. As a science, astronomy follows the scientific process involving evidence and data. These thirteen constellations just happened to be aligned in such a way as to make the Sun appear to pass through them.
If we wanted to and were endowed with supernatural powers , we could alter Earth's orbit so that the Sun appears to move through other constellations. Neither Lupus nor Lyra can be zodiac constellations, however, because the Sun doesn't "move through them. A person is considered to be a "Virgo" or a "Leo" if the Sun occupied that constellation when you were born. However, the astrological calendar hasn't taken precession into account. Earth's poles precess over a 26, year period and therefore the constellations aligned along the Sun''s path, called the ecliptic, shift stations slowly over time, by about one degree every 73 years.
The dates the astrologers associate with the zodiac were valid about 2, years ago. For instance, the Sun was once in Aries on the first day of Spring. Now, it is in Pisces. Today, the term zodiac is mostly associated with astrology, with the 12 signs of the western zodiac corresponding to the 12 constellations seen along the ecliptic. The so-called cardinal signs Aries , Cancer , Libra and Capricorn mark the beginning of the four seasons, i.
The largest of the 12 zodiac constellations is Virgo , which covers Virgo is also the second largest of all 88 constellations, only slightly smaller than Hydra. Covering an area of Also located in the southern celestial hemisphere, Aquarius represents Ganymede, the cup bearer to the Olympian gods in Greek mythology.
Leo , the third largest zodiac constellation, occupies an area of It represents the Nemean lion, a mythical monster defeated by Heracles as part of his 12 labours. Pisces comes in 4th with
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