NASA astronaut Don Pettit shot this beautiful long exposure photograph showing star trails and city trails from the International Space Station. The image was created by combining 18 separate long-exposure photographs. Pettit says,
My star trail images are made by taking a time exposure of about 10 to 15 minutes. However, with modern digital cameras, 30 seconds is about the longest exposure possible, due to electronic detector noise effectively snowing out the image. To achieve the longer exposures I do what many amateur astronomers do: I take multiple 30-second exposures, then ‘stack’ them using imaging software, thus producing the longer exposure.
See those blue blotches that appear in a line on the face of our planet? Those are lightning flashes.
First things first, the most important thing to do is to plan well. Forward planning is vital to any night sky shot, along with a steady tripod and a warm coat. There are quite a few websites and twitter feeds that can help you with your planning. Even though it only takes about an hour and a half for the ISS to complete an orbit of the planet, you could be waiting quite some time under the night skies before the station appears above. The station only appears for a short time (about 1-2 weeks) and then re-appears again many weeks later. This is due to the orbit of the station above earth.
You can check out a collection of ISS photographs he has taken here.
Here’s a fascinating video by NASA that explains what auroras are and what they look like from space. It’s filled with beautiful photographs and time-lapse sequences captured by astronauts on the International Space Station. Astronaut photographer Don Pettit, who maintains a blog about his experiences, writes that taking pictures of Earth is harder than it looks:
Even with a shutter speed of 1/1000th of a second, eight meters (26 feet) of motion occurs during the exposure. Our 400-millimeter telephoto lens has a resolution of less than three meters on the ground. Simply pointing at a target and squeezing the shutter always yields a less-than-perfect image, and precise manual tracking must be done to capture truly sharp pictures. It usually takes a new space station crewmember a month of on-orbit practice to use the full capability of this telephoto lens.
Another surprisingly difficult aspect of Earth photography is capturing a specific target. If I want to take a picture of Silverton, Oregon, my hometown, I have about 10 to 15 seconds of prime nadir (the point directly below us) viewing time to take the picture. If the image is taken off the nadir, a distorted, squashed projection is obtained. If I float up to the window and see my target, it’s too late to take a picture. If the camera has the wrong lens, the memory card is full, the battery depleted, or the camera is on some non-standard setting enabled by its myriad buttons and knobs, the opportunity will be over by the time the situation is corrected. And some targets like my hometown, sitting in the middle of farmland, are low-contrast and difficult to find. If more than a few seconds are needed to spot the target, again the moment is lost. All of us have missed the chance to take that “good one.” Fortunately, when in orbit, what goes around comes around, and in a few days there will be another chance.
This past Sunday, a group of amateur astronomers in San Antonio, Texas successfully “flashed” the International Space Station with a blue laser and spotlight as it whizzed by overhead. While this might sound like an easy thing to do, it’s much more complicated than you think. Astronaut Don Pettit shot the photo of the experiment seen above, and writes,
This took a number of engineering calculations. Projected beam diameters (assuming the propagation of a Gaussian wave for the laser) and intensity at the target had to be calculated. Tracking space station’s path as it streaked across the sky was another challenge. I used email to communicate with Robert Reeves, one of the association’s members. Considering that it takes a day, maybe more, for a simple exchange of messages (on space station we receive email drops two to three times a day), the whole event took weeks to plan.
The International Space Station maintains an orbital altitude of between 205 and 255 miles, so the fact that Pettit was able to see the flash of light from that distance is quite impressive.
The Suomi NPP satellite is in a polar orbit around Earth at an altitude of 512 miles (about 824 kilometers), but the perspective of the new Eastern hemisphere ‘Blue Marble’ is from 7,918 miles (about 12,743 kilometers). NASA scientist Norman Kuring managed to ‘step back’ from Earth to get the big picture by combining data from six different orbits of the Suomi NPP satellite. Or putting it a different way, the satellite flew above this area of Earth six times over an eight hour time period. Norman took those six sets of data and combined them into one image.
So rather than being a composite of multiple images captured from the same perspective, they do in fact map images captured by the satellite onto a 3D sphere. Read more…
NASA photographer Lauren Harnett captured this photograph of the International Space Station passing in front of the moon. What’s amazing is that it didn’t require any fancy astronomy equipment — Harnett was shooting from a parking lot using a Nikon D3S, 600mm lens, 2x teleconverter, heavy duty tripod and sandbag, and a remote shutter release. She shot at 1/1600, f/8, and ISO 2500 in burst mode, and then combined the resulting photographs into this one image.
Over the past year, there have been a number of jaw-dropping (and viral) time-lapse videos created from the amazing photos captured from the International Space Station by astronaut Mike Fossum. The video above provides an interesting behind-the-scenes look into how the images are captured.
Between August and October of this year, the crew onboard the International Space Station used a Nikon D3S (at high ISOs) to capture photographs of Earth as they zipped around it at 17,000mph. Michael Konig then took the footage and compiled it into this eye-popping time-lapse video showing what our planet looks like from up there. Read more…
This incredible time-lapse video was created using photos captured from the International Space Station at night.
[It] begins over the Pacific Ocean and continues over North and South America before entering daylight near Antarctica. Visible cities, countries and landmarks include (in order) Vancouver Island, Victoria, Vancouver, Seattle, Portland, San Fransisco, Los Angeles. Phoenix. Multiple cities in Texas, New Mexico and Mexico. Mexico City, the Gulf of Mexico, the Yucatan Peninsula, Lightning in the Pacific Ocean, Guatemala, Panama, Columbia, Ecuador, Peru, Chile, and the Amazon.