Astronomy
Astronomy is the study of the stars and planets. The first telescope was invented by an Astronomer named Galileo Galilie he built the first refractor telescope. The first reflector telescope was invented by Isac Newton.
Before the first telescope was invented people did not know how the planets looked close up. They could only see bright lights in the sky. Now we have advanced equipment such as the Hubble Space
Telescope to view far away stars and nebulae.
Observatories are buildings with huge telescopes inside that allow astronomers to see objects in deep space. Observatories are usually placed on top of mountains and high areas, such as the Keck telescopes built on top of a 4,200 metre high dead hawaiian volcano. The twin telescopes are eight storeys high with mirrors which are ten meters wide.
A refractor telescope uses lenses which are thick and will blur the light from objects that are faint. And lenses focus different parts of the light spectrum at different areas, which blurs the image so it will be harder to view. Reflector telescopes don't use a lens instead they use mirrors to view the image and do not blur the image. A reflector telescope uses two mirrors the primary and secondary. The primary mirror forms the picture but the secondary mirror is needed to direct the light into the eyepiece.
At the beginning of the twentieth century living in space was only a dream. However, in the year 1971 that dream came true with the launch of Salyut 1, the very first space station which was built by the Soviet Union. Two years later Skylab was launched and was the first US space station to orbit the Earth.
Mir, which was launched in 1986, is the oldest surviving space station. Because of the cramped conditions on Mir it is very untidy inside. However, it has had cosmonauts on it since 1987 and some even remain on board for over a year.
The International Space Station, or ISS for short, is the largest space station in history. In 1998 the very first module of the ISS was launched. It was called Zarya. It provided power, propulsion, guidance, and storage. The ISS will continue to be constructed until 2011 and will hold a crew of seven.
A rocket launch is very expensive and most of the rocket is destroyed during the launch procedure. Engineers had to design something that could be used over and over again and they eventually came up with the Space Transport System or space shuttle. We use space shuttles to dock at the ISS, deploy satellites, and get astronauts to the Hubble Space Telescope to fix it.
To blast off of Earth a space shuttle uses two solid rocket boosters because it's engines aren't powerful enough to escape Earths gravity. Once the fuel in the external rocket boosters is all used up they are jettisoned and will fall back to Earth and use parachutes to gently land on the ground to be recycled. The external fuel tank is released and will burn up in the Earths atmosphere. Next the shuttle will enter a low Earth orbit. It could stay in space for two weeks doing all sorts of tasks such as repairing the Hubble Space Telescope or deploying satellites. Now the orbiter will position itself for the journey back to Earth. When the space shuttle re enters the Earths atmosphere friction will cause it to heat up and create a bubble of plasma around it. It then prepares for a high speed landing on a runway which is 4.5 km. It releases parachutes to help it slow down.
Astronomy Freeware
Planetarium Software
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope. It is being used in planetarium projectors. Just set your coordinates and go.
