"To confine our attention to terrestrial matters would be to limit the human spirit. " Stephen Hawking

I have always been interested in science and cosmology. I am fascinated by the universe and the theories of scientists. Newton discovering gravity, Kepler's law of planetary motion, Galileo's discovery of the first 4 of Jupiter's moons, Einstein's theory of relativity, Hubble and his expanding universe, Penzias and Wilson "heard" the Big Bang and now the scientists are working on how fast the universe is expanding and the "theory of everything"!

Some of the different kinds of celestial bodies are planets, moons, stars, comets, meteors, asteroids and galaxies. Some of the different kinds of star groups are constellations, open clusters, globular clusters, double stars, variable stars and nebula. Our galaxy is called the MILKY WAY. There are billions of stars in the Milky Way. Sometimes when you look up at the night sky you can see the hazy light of millions of stars along the edge of the Milky Way. All the stars that we can see are within our galaxy. A very close neighbour galaxy that we can see without optical aid is the ANDROMEDA GALAXY. Andromeda is 2,300,000 (2.3 million) light years away. This is the furthest object that humans can see without the use of some type of optical aid. There are billions of other galaxies. The Hubble Space Telescope took a picture of the universe that shows 1,500 galaxies in a tiny patch of sky no bigger than a grain of sand held at arms length. A TIME LINE OF ASTRONOMY AND LIFE Through Astronomy, scientists have discovered the oldest known objects in the universe are about 14 to 18 billion years old. The stars of the globular cluster M13 in Hercules are about 14 billion years old. The stars of the open cluster M67 in Cancer are about 10 billion years old. 4 ½ billion years ago our Solar System began. Our Sun and planets began to form a distinct group held together by gravitational attraction. 4 billion years ago the first bacteria life forms began on Earth. 600 million light years away lies a group of galaxies we see in the constellation Hercules. 400 million years ago the stars of the Hyades, the "V" in Taurus, were formed. 240 million years ago dinosaurs began living on Earth. 70 million years ago dinosaurs became extinct, probably from a meteor impact. When we look thru a telescope at M65 and M66, a pair of galaxies in the constellation LEO, the light we see is from 35 million years ago. These galaxies are 35 million light years away. 20 million years ago the stars of the Pleiades were formed. These are considered very young. 2.3 million years ago, the light we see now from the Andromeda Galaxy began its journey toward us. The Andromeda Galaxy is the furthest object that humans can see with the unaided eye. It is about 2.3 million light years away. It appears as a little hazy spot in the sky. 2 million years ago the first species of human life began on Earth. 300,000 years ago the Trapezium, the stars in the Orion Nebula were formed. 22,000 years ago, the light from M13 that we see now began its journey toward us. 4000 years ago, the ancient Babylonians and Macedonians referred to LEO as a lion. Many of the Stars and Constellations got their names in ancient times. About 400 years ago, around the year 1600, the telescope was invented. In 1610, Galileo was the first to see Jupiter’s moons and Saturn’s rings. In 1931, Edwin Hubble was the first using a telescope to see individual stars in the Andromeda Nebulae. This was the first time we understood this was a galaxy outside our own. Our Sun is a star, the closest one to us. The next closest star to us is called Alpha Centauri. It is 4 1/3 light years away. The light from Alpha Centauri that we see now began its journey toward us about 4 years ago. It would take the fastest spaceships we have, traveling at 20,000 miles per hour, nearly 150,000 years to reach Alpha Centauri. It takes 8 minutes for the Sun's light to reach us. The Sun is 93,000,000 (million) miles away. It takes 2 seconds for the moon’s light to reach us. It varies from 223,000 to 252,000 miles away. A light year is the distance light travels in one year. Light travels at the speed of 186,000 miles per second. So one Light Year equals 186,000 miles per second x 60 seconds in one minute x 60 minutes in one hour x 24 hours in one day x 365 days in one year = 5,865,696,000,000 miles, almost 6 trillion miles in one year.

"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. " Carl Sagan