Space Research SNC1D. Telescopes Astronomers find out about celestial objects by observing the light...

Space Research

SNC1D

Telescopes

Astronomers find out about celestial objects by observing the light coming from them.

Instruments used to collect and focus the light are called telescopes.

Observatories on an extinct volcano in Hawaii.

Telescopes

The first telescopes were refracting telescopes that used lenses to focus the light.

Telescopes

All large modern telescopes are reflecting telescopes that use curved mirrors to focus the light.

Telescopes

Telescopes can observe light outside the visible spectrum.

Radio telescopes of the VLA (Very Large Array)

Space Telescopes

Since the atmosphere blocks some wavelengths of light and also distorts visible light travelling through it, it is best to place telescopes in space.

The HST (Hubble Space Telescope)

Getting into Space

However, it costs a lot of money and fuel to put an object into space against the pull of Earth’s gravity.

Polar satellite launch vehicle

Getting into Space

It is also difficult to repair objects in space.

HST maintenance

Unmanned Probes

It is more cost-effective to send unmanned probes up because they do not require life support (oxygen, water, food) and do not suffer health problems from the microgravity.

Unmanned Probes

All of the exploration of objects beyond the Moon has been done by unmanned probes (e.g., the Mars rovers).

Fringe Benefits

Investments in the space program have not only allowed us to explore strange new worlds but also develop technologies that may be used on Earth, from blood pressure monitors to water purifiers to the detector in your digital camera.