Astronomy
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.
Ancient Astronomy
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.
Modern astronomy
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.
