2008 marked the first time in history that more of Earth’s population lived in cities rather than in the countryside, and by 2050 nearly 70% of the world’s population will reside in large cities. A new series of satellite photographs captured decades apart by NASA’s Landsat department and the U.S. Geological Survey offers a striking look at how human cities have spread across the face of the Earth in just a few short years. The image above shows Las Vegas in 1984 and in 2011. Read more…
This photo is what you get when you point a massive 4.1 meter telescope (VISTA in Chile) at an unremarkable patch of night sky and capture six thousand separate exposures that provide an effective “shutter speed” of 55 hours. It’s an image that contains more than 200,000 individual galaxies, each containing countless stars and planets (to put the image into perspective, the famous Hubble Ultra-Deep Field contains “only” around 10,000 galaxies). And get this: this view only shows a tiny 0.004% of the entire sky! Read more…
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.
We’ve seen quite a few videos lately by people who send cameras up to the edges of space on weather balloons. Here’s the big-budget version of that: footage from a camera attached to a NASA Space Shuttle’s booster rockets. Lift off from Earth occurs at 0:27, separation from the shuttle occurs at 1:57, and splashing into the ocean occurs at 7:21. The sound captured by the cameras has been remastered by George Lucas’ Skywalker Sound.
If you’ve always wanted to be an astronaut photographer shooting images of Earth from a window of the International Space Station, Stratocam is an app for you. Created by Paul Rademacher, it allows you to snap your own photographs inside Google Maps’ satellite view of our planet. You can also view and rate other people’s photos, and browse the highest rated images from around the world. Read more…
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.
On December 31st, 2011, Oaida Raul decided pay a tribute to the recently-retired Space Shuttle program by creating a GoPro video of a Lego Space Shuttle model traveling up to the edges of Earth’s atmosphere on a weather balloon. You can read an in-depth description of the mission and the components used — the entire project was launched and completed in a span of about a week — over on Raul’s blog.
Want to see how Las Vegas has grown from 1972 through 2010? NASA created this unique time-lapse video using photographs captured by Landsat satellites. From this perspective, it almost looks like humans are a mold spreading across the face of a fruit.
Captured on April 1, 1995 by the Hubble Telescope, the photograph Pillars of Creation is one of the most famous space images ever made. Here’s a crazy fact though: did you know that the “pillars” seen in the photo were already long gone by the time the image was captured? Astronomers have concluded that the pillars — which measure up to 4 light years in length — were destroyed about 6,000 years ago by the shock wave from a supernova. Because of how long it takes light to travel across such vast distances, we can currently see the shock waves approaching the pillars but won’t actually see their destruction for another thousand years or so!
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…