The Milky Way
Our Solar System is over 250 A.U. in diameter, a huge size on human scales, but it is beyond tiny when compared to the wider Universe. Our Solar System is not travelling through Space alone, instead it is part of a much larger collection of billions of stars, dust and gas that is held together by Gravity, known as the Milky Way.
Our Star (the Sun) is one of 400 Billion stars in our Galaxy. The Milky Way is a Barred Spiral type Galaxy approximately 100,000 light years across.
The Milky Way Galaxy as seen from Earth (from within the Galaxy)
The Milky Way as would be seen if we could travel 1 million Light Years away
The image below shows our location within the Milky Way galaxy:-
Beyond the Milky Way
Even the size of the Galaxy is tiny when compared to the rest of the Universe.
The following videos show an explanation of the Universe by Professor Brian Cox (over two episodes):-
Robotic Telescope Imaging
The National School's Observatory
Created by Liverpool John Moore's University to provide UK schools with access to a professional 2 meter wide robotic telescope primarily designed for scientific research.
Through the NSO website, school students are able to request observations by a telescope worth millions of dollars, producing images that show the Universe in exquisite detail. The following images were all taken by S1 to S6 students in Mr Wilkinson's classes:-
But images from research telescopes are not simply pretty photos, but contain large quantities of valuable scientific data. Scientists use the gathered light to learn everything they can about the Universe.
To stop valuable data being lost, unlike a digital camera, the images received by the telescope have not been processed in any way. This means that Scientists have to process the images themselves.
The processed image is in black and white. This is because the telescope can only image in one colour (one Wavelength of light) at a time. So how does a colour image get made ?
In the S1 Energy topic, it was seen that all colours can be made by mixing together Red, Blue and Green Light.
Our eyes work in the same way to create a colour image. There are two types of light detecting cell in our eyes, Rods (which detect brightness) and Cones (which detect colour) .
Our eyes have three types of Cones, one to detect red light, one to detect blue light and one to detect green light.
By combining the signals for each of these Cones, a full colour image is created by the brain. The same process can be used to make full colour Astronomical Images:-
By stacking the 3 different colour images on top of each other, a full colour image can be made.