I was going to write about the Brian the Bat today, and his apparently untimely demise during the launch of Space Shuttle Discovery a few days ago, but I see that Ian O’Neill over at Universe Today has covered it nicely, so go check it out. Instead, I’m going to give you another gorgeous scene from our favorite planet (at least here at the Rambling Hacienda)–Mars. This one is absolutely stunning in its detail — a set of dunes in Proctor Crater in the southern hemisphere of the planet. Click on it to get the big view and just feast your eyes. Then come back here for a discussion of it.
Sand dunes and ripples in Proctor Crater on Mars. Courtesy Mars Reconnaissance Orbiter. (Click to embiggen.)
This view was snapped by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter, and it shows what geologists call aeolian bedforms. The term aeolian is used to indicate “wind-blown” materials that were blown across the surface and deposited in features like these dunes and ripples.
On this image, the relatively small ridges are ripples made up of very fine sand mixed with a bit of larger sand bits and granules of rock. The larger dunes are made of sand as well and they move faster across the surface than the ripples do. All of the material you see here is made of rocks that once flowed from volcanoes (known as basaltic lavas).
What I really find very cool is to study the large version of this image (which you can get to by clicking on this smaller one — it may take a bit to open — it’s big). Do that and you can see even finer ripples in the dark areas and ripples within ripples within ripples in the brighter areas. It’s just amazing detail and I want to be there digging into the sand with my geologist’s shovel and taking samples!!
My last entry featured a lovely image of Saturn and several of its moons. I hope you had a chance to look it over because it’s really quite breathtaking. The image was part of a sequence of images that were taken with HST and those images were used to make a scientific visualization of the event. Was it a movie? An animation? Or what?
As Frank Summers, a scientific visualizer who works at Space Telescope Science Institute explains in a thought-provoking blog entry about the images and animation of this event (work done by artist Greg Bacon), HST is not a movie camera. It’s an observatory. And the images it takes can be used to make visualizations that help us understand the science behind the observations. There’s a fine line there and he discusses it in a nicely written entry about visualizations, movies, and animations.
Science visualizations are part of my life as a producer of various bits of media for astronomy outreach. I’m always on the lookout for good viz, so to speak, and in my own mind I know the difference between data-driven visualizations versus actual imagery. But, that may not be true of audience members who simply see the visual work and accept it as a simulation or real image or whatever it’s being represented as. Digital manipulation of data in the service of education and outreach is very common in our field. And, I suspect that we’ll always have the question of “is it visualization, an image or an animation?” And, when does it matter and when doesn’t it? Frank talks about that — so go check it out — from the blog of the master.
