Astronomy is about studying space, the universe, stars and the planets in our solar system. Astronomers are scientists who try to find answers to questions relating to our universe. They observe planets, faraway stars and galaxies as well as certain events that occur in space. They examine the structure of the universe and try to find out how it all began.
Astronomy has been around for thousands of years. In ancient times, people observed the sun and the stars on a daily basis. They planted crops and held certain events relating to the movement of objects in the sky.
Ancient civilizations, like the Greeks and Romans, however did not have the instruments that later generations had. They had to observe the skies and stars with their naked eye. It helped them navigate the seas and guide them to other places.
They saw that stars were arranged in patterns that looked like humans or animals.
In ancient times, people thought that the Earth was the centre of the universe and that everything revolved around it. Towards the end of the Middle Ages some astronomers were not quite convinced about this theory. In the early 16th century Nicolaus Copernicus, a Polish astronomer, was the first to show that in fact the sun was the centre of the solar system and planets revolved around it. Almost a century later Italian astronomer Galileo used the first telescope to observe space. His studies supported Copernicus’ theories. German mathematician Johannes Kepler proved that planets travel around the sun in elliptical paths. Isaac Newton used Kepler’s findings to explain how gravity worked.
The discovery of the telescope changed the way scientists could observe space. While ancient people only were able to see objects near Earth, telescopes were able to find Uranus, Neptune and Pluto, the distant planets of our solar system.
Astronomers also found that an asteroid belt moves around the sun between the Earth and Mars. With the help of powerful telescopes, they were able to map the surface of the moon and other planets in great detail.
Modern astronomy uses powerful telescopes on earth to see objects far away from our solar system. It also relies on images sent to earth from orbiting telescopes, like the Hubble Space Telescope, which has been in operation since 1990.
Unmanned spacecraft that land on the moon and other planets give astronomers large amounts of data and images that they can use for their work. Astronomers also study samples of rocks that spacecraft have brought back to Earth.
Today, astronomers use computers to simulate movements and events that may happen in space. For example, they can predict how close an asteroid can come to earth or when certain comets appear.
Astronomers measure distances in light years – how far light can travel in one year, which is about 6 trillion miles (9.4 trillion km). They have found out that our galaxy, the Milky Way, has a diameter of 100,000 light years. The nearest star is Proxima Centauri, about four light years away from Earth.
- The Milky Way
- The Solar System
- Black Holes
- Isaac Newton - A Great Scientist
- Stars - Great Balls of Gas in the Universe
- Hubble Space Telescope
- First Planet From Outside Our Galaxy Found
- Hubble Sees Asteroid Break Up
- Astronomers Use New Methods in Search of Life in Our Universe
- Mars One
- Near EarthAsteroids - How Dangerous They Are
- Astronomers Discover Earth-Sized Planets Around Nearby Star
- Voyager Spacecraft Continues Mission to Outer Space
- amount = quantity
- ancient = old, long ago
- arrange = to put into a special position or order
- asteroid belt = many small planets that move around the sun
- century = a hundred years
- certain = special
- convince = to prove to someone that what you say or think is true
- crop = plant, like wheat, corn or rice, which is grown by farmers and used as food
- daily basis = every day
- data = information
- diameter = straight line from one side of a circle to the other
- discovery = when you find something new, that was not known before
- distant = far away
- elliptical path = route that moves around an object in an ellipse
- examine = look at very carefully
- finding = discovery, result
- galaxy = one of the large group of stars that make up our universe
- great detail = here: to put in a lot of information
- guide = lead, show
- however = but
- image = picture
- later =future
- map = draw
- measure = to find out how far away something is
- movement = when an object moves
- naked eye = to see something without anything to help you
- navigate = steer ; find the way
- observe = watch closely
- occur = happen
- orbit = move around
- pattern =design, shape
- predict = tell that something will happen in the future
- prove = to show that something is true
- relate = about something
- revolve = move around
- sample = piece of something
- scientist = person who has studied science and works in a laboratory
- simulate =to make something feel real
- solar system = the sun and the planets that move around it
- studies = the work that someone does to find out more about a topic
- support = back up, help
- surface = the top parft of something
- trillion = 1,000,000,000,000,000
- unmanned spacecraft = object that can travel into space without anybody guiding it