Washington, July 19 (): On Friday 19 July, between 10.27 pm and 10.42 pm IST, NASA’s Cassini spacecraft will photograph the Earth from its orbit around Saturn.
Linda Spilker, scientist of Cassini project at NASA’s Jet Propulsion Laboratory in Pasadena, CA said that Cassini had earlier photographed Earth, but this would be the first time the Earthlings know in advance their picture would be taken from a billion miles away. She also hoped that people around the world would go outside to wave at Saturn while the photo-shoot is under way.
Earth’s first image was taken 23 years ago by NASA’s Voyager 1 spacecraft beyond Neptune. The second was Cassini’s image from the Saturn system in 2006.
It is estimated that this time the Cassini spacecraft will be at a distance of about 1.44bn km away from Earth when the photograph is taken and while the Earth will be 1.5 pixels wide in the resulting image.
At the time of photographing, the sun will light up North America and parts of the Atlantic Ocean, while Europe and Africa, although facing Cassini’s cameras, will be in darkness.
Cassini spacecraft was launched in 1997 and it has been orbiting Saturn since July 2004. Even though the spacecraft has photographed the Earth twice during this period, this is the first time Earthlings have known about it in advance.
The image captured by Cassini will be the first to capture the Saturn system with Earth in natural colour, as human eyes would see it. It will also be the first to capture Earth and its moon with Cassini’s highest-resolution camera.
The rings of Saturn are too wide to capture it in a single image, so the spacecraft will take a series of exposures. All the images will be combined on Earth to produce a breath-taking mosaic.
Spilker added the whole mosaic of the backlit rings will be incredible when it is put together.