NASA'S MISSION VOYAGER

THE MISSION VOYAGER  This mission was started on 20 August 1977. In this mission NASA launched a spacecraft named voyager. This spacecraft was about 6000 billion kilometers away from Earth.

Voyager 1

This spacecraft was made to concentrate research to planet Saturn. It was the first man made spacecraft who leaved the solar system. It had acquired about 60 frames.

In 1990 14 February spacecraft took last photograph of earth at the request of some scientists and Carl Sagan author of book THE PALE BLUE DOT . In this photograph earth seems to be pale blue and very small compared to vast universe. This why the author Carl Sagan took the phrase "THE PALE BLUE DOT" which is about significance of the photograph taken about 6000 billion kilometers away from earth or 4000 billion miles away from earth.

In this photograph,size of earth is smaller than 1 pixel.The coincidence of this photograph is that earth is lying in middle of rightest part of scattered light. Also these scattered light of sun has been formed as a result of taking so close of sun the image of of earth. So this is not actual scattered beam of light it is just an artifact.

This mission has been extended to these days. About 42 years,11months have completed .This spacecraft is still moving with speed of 64000km/hr.

This spacecraft captured the photograph of earth using three frames ie; violet, blue, green and combined together to form a colour image of earth.

This spacecraft is now used for research on Boundary of Solar System including kuiper belt, heliosphere and interstellar space.

The reason why the earth is looking as a pale blue dot is the scattering of light. We know that scattering of light is inversely proportional to 4th power of wavelength .

This is the reason why our sky looks blue

The blue light scattered mostly and white light reflected by the cloud combines with the blue light making sense of pale blue colour.