Comments for http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml en-gb 30 Fri 30 Jan 2015 07:14:26 GMT+1 A feed of user comments from the page found at http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml wfastronomer http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml?page=80#comment4 I have made several colour images using astronomical data. These images all start of as several monochromatic images taken through different filters, and these are processed together to make a colour image. A combination blue, green and red filters are close to what the eye perceives. The images are usually combined to try to give the best dynamic range - so that as many features as possible are visible including diffuse and concentrated structures - a log scale or asinh are usually best. These are often quite pleasing to the eye. Apart from this and the removal of artifacts all the processing is usually for scientic purposes and not to try to give true colours. The Tadpole, which I helped in the processing of, was taken in 3 filters: g, V, I. g is between blue and green, V is close to red, and I is into the infrared as far as the eye is concerned, but are often classed as visible by atronomers since the detectors that cover the visible also can detect a little beyond where the eye can see. We made the colour image When we process observations in the near infrared such as those with the new Hubble WFC3, we select the shortest wavelength filter as blue, the longest as red and one in the middle as green. The near infrared images don't look quite as nice usually because most stars have the same near infrared colours. Observing in dusty regions can create nice near infrared images, because the extinction caused by dust reddens some stars and creates a wider range of colours:http://surveys.roe.ac.uk/wsa/gallery/wsa_misc/SerpensCloudCore.html Sat 19 Sep 2009 18:24:38 GMT+1 ghostofsichuan http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml?page=60#comment3 These are the ventures that should humble mankind but sorrowly do not. At some point in time we will either abandon this earth or be on it when some other planets in some other galaxies have a spectacular view of our extinction. As we sit in awe of the past we are actually viewing the future. Thu 17 Sep 2009 19:48:05 GMT+1 Jonathan Amos http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml?page=40#comment2 Are the colours real? It is a great question. Sometimes, yes; sometimes, they are an "interpretation" designed to emphasise particular features or simply to visualise stuff that is beyond detection by human eyes. The Hubble people themselves have a very good explainer here if you want to know more. I think this probably calls for a separate post, too, when we get the first science demonstration images from the Herschel space telescope. They will come in the next few weeks. These will be the first images we've seen that have been taken with instruments that are fully set up. These also will be coloured; and, of course, they will be of objects that are beyond the vision of even Hubble (because they are in the far-infrared). Herschel has an additional problem - if I can call it that - in that its images do not look anything like as sharp as the Hubble pictures because of the wavelengths it is detecting. That is just the nature of light. Tue 15 Sep 2009 13:16:17 GMT+1 JohnnyParanoia http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml?page=20#comment1 @tiggertoo:The colours that we perceive correspond to differing wavelengths of light. The light that is visible to our eyes has wavelengths of between around 400 nanometres to around 700 nanometres.When light hits the particles in a planet's atmosphere, it can be scattered, but its wavelength (i.e. its colour) will not be changed by the scattering.The lack of particles (of matter, as opposed to particles of light) in space makes it easier for the light to travel the enormous distances to us across space - it has no effect whatsoever on the colour (wavelength) of the light.The 'false colour' pictures that ESA & NASA often publish are images that have been created from data gathered by telescopes that can detect wavelengths (colours) of light that the human eye cannot see - e.g. infra-red, ultra-violet, or X-rays. Scientists add 'artificial colours' to those pictures so that non-scientists like us can get some impression of the range of wavelengths that their telescopes can 'see' coming from, say, a distant galaxy. Thu 10 Sep 2009 22:00:20 GMT+1 kenneth jessett http://www.bbc.co.uk/blogs/thereporters/jonathanamos/2009/09/hubble-still-has-what-it-takes.shtml?page=0#comment0 Is there colour in space? I would have thought the absence of particles would not have provided for colour to be transmitted, or are these images 'colour added' back here on Earth? Thu 10 Sep 2009 20:07:05 GMT+1