Cool images of Saturn and its moons taken by Cassini probe.

thanks

Lapetus at 2400 mi. That is some hellacious topography.

This shot is amazing.

not sure if anybody here knows for sure but I figured I'd ask. Somebody told me once that many of the pictures we see of galaxies and planets with vibrant colors are colorized. Most of the images are actually black and white and the color was added for basically marketing purposes.

Is that true?

Thanks, B! Good link.

@blahh:
Coloring the Universe: Why Reality is a Gray Area in Astronomy

"...Levay says the process of coloring photos is never arbitrary.

"What we're doing is representing physical processes and representing actual astronomical observations in a visual and artistic way," Levay explained shortly after discussing the issue with Brecher. "I'm adding value, but it's not arbitrarily added. What I'm mostly doing is enhancing what's already there...."

Glad you brought the point up and made me want to know how that worked.

cool thanks

They are all colorized. But it's not for marketing purposes: the problem is that they have no way to produce RGB color photographs, because there is no need nor any use for such things from a scientific standpoint, so they don't have the equipment to do so.

The Red, Green and Blue our eyes see are good colors on Earth because our sun happens to emit energy strongest in green, and because Earth's atmosphere happens to scatter that light between reds and blues. The RGB colors aren't interesting away from Earth's atmosphere and especially away from the Solar System.

The *are* many interesting "colors", but few/none that can be seen by the human eye. Telescopes and such have filters to photograph those interesting "colors". My amateur telescope was set up to do five colors, and while RGB were three I wound up not using them much (H-alpha and L almost always looked better)

When a large observatory on Earth wants a publicity photo that really is RGB they usually get one from the amateur astrophotographers. My understanding is that no large observatory in the US has bought RGB filters since the 1930s, that only a couple of PR departments have any, and that those PR departments don't get much telescope time at $1 per second on the big telescopes. Cassini and other space probes can't do RGB at all, so it's either black & white or colorize.

These are probably all L shots (black & white). They'll always start with one of those to find out what's there, to decide what needs a closer look with filters. L tells you what's there, but not what it's made of - for that you need other filters.

All CCD sensors are black & white (Fovean is like a three black & white CCDs in one where you can't change filters). Imaging spectrometers can see color but they have all kinds of drawbacks and are only used in special situations (and are *way* outside the budget of any amateur).

A really good amateur astrophotographer is Robert Gendler. His are colorized to an extent too because he wants to add the interesting detail (which isn't visible in RGB).