Here’s a really unique video from one of our favorite astrophotographers, Thierry Legault. Thierry sent us a full HD time-lapse of the full sky during one full night (August 7-8) over the Pic-du-Midi Observatory in the French Pyrenees. At 2,877 meters in altitude, this is the highest observatory in France. The video is taken with a fisheye lens, and so the view creates what appears to be a tiny little world (Planet Pic-du-Midi, perhaps?). Visible are Saturn and Mars, then the Moon, Jupiter and Venus. And a passage of the ISS and an Iridium flare complete the planet-like scene. “The rotation of the sky around Polaris is easily noticeable,” Thierry wrote to Universe Today, “as well as the movement of circumpolar constellations such as Big Dipper. The main dome is the 1-meter telescope, I was there with three friends to learn how to use this telescope for future planetary missions. This telescope was used in the 60’s to prepare the Apollo lunar missions because of the quality of its optics and the very good seeing of this site.”
Astrophotographer Thierry Legault had told us he was traveling to Australia for the Transit of Venus, so we knew he had something special planned. But that still didn’t prepare us for the awesomeness of what he has just achieved. During the Transit of Venus, Legault also captured the Hubble Space Telescope moving across the face of the Sun. Not once, but 9 times, during the HST’s transit time of .97 seconds. “Thanks to the continuous shooting mode of the Nikon D4 DSLR running at 10 fps,” Legault said on his website, which shows his new images. Of course, due to the differences in distance from Earth of Hubble vs. Venus, Venus took a lazy 6-plus hours to make its transit. A few giant sunspots also join in the view.
Below see a close-up of the two transits and a look at Legault’s set-up in the Outback of Queensland.
Legault noted that just one of the telescope/camera setups was his. So, he had just one chance of capturing the double transit. And he nailed it.
Here’s the map from CalSky of where the HST transit would be visible, just a thin band across the top of Queensland:
Legault said he has some more images on the way, including the ring of the atmosphere of Venus around the first contact, images of the transit in H-alpha, and the full ring of Venus 24 hours after the transit, so keep checking his website for more fantastic images.
Congratulations to Thierry Legault for a truly amazing and special capture of the Transit of Venus, something that won’t happen again in our lifetimes. And thanks to Thierry for sharing his images with Universe Today.
Astrophotographer extraordinaire Thierry Legault has made a name for himself with his images of spacecraft transiting across the face of the Sun. He has done it again by capturing the first-ever image of the Tiangong-1 space station transiting the Sun. The monster sunspot, AR 1476 absolutely dwarfs the Chinese space station (inside the circle), but you can see incredible details of the Tiangong-1 below in a zoomed-in version. Legault had less than a second to capture the event, with the Tiangong traveling at 7.4km/s (26500 km/h or 16500 mph,) the transit duration was only 0.9 seconds! The size of the station is pretty small — as without solar panels the first module of the Tiangong measures just 10.3 x 3.3 meters.
Legault’s equipment was a Takahashi FSQ-106 refractor, a Baader Herschel prism and Canon 5D Mark II camera. Exposure of 1/8000s at 100 ISO.
As Legault told us in an interview earlier this year, in order to capture such images he studies maps, uses CalSky software, and has a radio synchronized watch to know very accurately when the transit event will happen.
“My camera has a continuous shuttering for 4 seconds, so I begin the sequence 2 seconds before the calculated time,” he said. “I don’t look through the camera – I never see the space station when it appears, I am just looking at my watch!”
For a transit event, he gets a total of 16 images – 4 images every second, and only after he enlarges the images will he know if he succeeded or not.
“There is a kind of feeling that is short and intense — an adrenaline rush!” Legault said. “I suppose it is much like participating in a sport, but the feeling is addictive.”
Thanks to Thierry for sharing his latest success, and you can see larger versions of these images, and much more at his website.
Take a look at the collection of images above. All are high resolution astrophotos of different artificial satellites, taken by renowned astrophotographer Thierry Legault, using one of his 10″ telescopes and a simple webcam. The images have been sharpened and enlarged so that it’s easy to see small structures on the satellites such as antennas or solar panels.
Like this one, which is surely the Soyuz, with solar panels on each side:
These are pretty awesome images….
…except Thierry and I are not telling the truth.
These images are not of satellites, but are all pictures of the star Vega.
What you have just seen is an example of what Legault calls “Bad Astrophotography,” a phrase Legault uses in homage to Phil Plait and his Bad Astronomy blog. Basically, this means that because of image artifacts or over-processing you can be fooled – intentionally or unintentionally — into seeing something that is not really there.
“In any raw image there is noise and if you process this image too strongly, the noise appears and some processing can transform the noise into something that looks like detail – but it is not detail,” said Legault.
So just like the images that have been touted as the Bigfoot on Mars, or even blurry pictures of supposed UFOs, sometimes astrophotos can look like something they are not.
“Many people are not aware that an image is not reality — it is a transformation of reality,” Legault told Universe Today, “and any image that is taken under difficult conditions or close to the resolution limits of the telescope, the image is less and less reliable or reflects less and less the reality.”
Many things can cause problems in astrophotography:
– atmospheric turbulence, which can distort images and even create false details or make real ones disappear
– the unavoidable shaking of the telescope due to manual tracking, especially in satellite imaging
– noise, the variation of brightness or color in images, due to sensor and circuitry of a digital camera, or the diffraction of light from the telescope
These problems may be hard to avoid, depending on your equipment and level of skill. So what should an astrophotographer do?
“The solution for these issues is to be careful with processing,” Legault explained. “I’ve often said the best, most skilled person in imaging processing is not the one that knows all the possibilities of processing, but the person that knows when to stop processing an image.”
Over-processing, such as multiple smoothing, sharpening and enlargement operations, or layer transformations and combinations in Photoshop can create false details in images.
The issues with the lead image in this article of all the “satellites” — the structures and the different colors you see — are mainly caused by atmospheric turbulence and noise in the raw images, combined with effects from the color sensor in the camera.
Think of how when you look at a star that is low on the horizon with the naked eye, you see twinkling, and sometimes even changes in color, so the atmospheric turbulence can definitely make an effect on colors.
“When you observe a star through a telescope at high magnification, it can become even more distorted,” Legault said. “You have spikes, distortions and changes in shape, and a star that is supposed to be a point or a disk, unfortunately, by turbulence is transformed into something that is completely distorted and can take many shapes.”
Additionally, Legault said, combining the distortions with an effect from color sensors in the camera, called the Bayer sensor, can cause additional issues.
“For the sensor, you have pixels by groups of four: one red, one blue and two green in square,” Legault said, “and you can easily imagine that if the object is very small, such as a very small star, the light can fall on a red pixel and then the image can become red. Then the image of the star is distorted and you have some spikes that fall on a different color pixel.”
And then the processing does the rest, transforming turbulence and camera artifacts into details that may look real, Legault said.
Legault recalled an amateur who, a few years ago, published an image of Saturn’s moon Titan.
“The image contained surface details and a sharp disk edge,” he said, “and looked quite convincing. But we all know that Titan is covered with an opaque and uniform atmosphere, and surface details can’t be seen. The details were actually only artifacts created from noise or other image defects by over-processing a poor resolution image with multiple upsizing, downsizing, sharpening and smoothing operations.”
What’s an amateur astrophotographer to do?
So, with more and more people doing astrophotography these days, how can they make sure that what they think they are seeing is real?
“There are solutions like combining raw images,” Legault said. “When you combine 10 or 20 or 100 raw images, you can decrease the noise and the image is more reliable and less distorted by turbulence.”
For example, take a look at the images of the space shuttle Discovery below. The two left images are consecutive single frames, processed by smoothing (noise reduction), sharpening (wavelets) and was enlarged 3 times.
The first and second images, although blurry, seem to show lots of very small details. But when they are compared together or with a combination of the 27 best images of the series (on the right), only the larger structures are finally common.
“The bright line marked A is not real, it is an artifact likely caused by turbulence,” Legault said, “and if it were an image of the space station taken during an EVA, I could perhaps claim that this detail is an astronaut, but I would be wrong. The double dark spot marked B, could be taken for windows on top of the cockpit of Discovery. But it is not real; if it were an image of the Space Station, I could claim that it’s the windows of the Cupola, but again I would be wrong. In C, the two parallel lines of the payload bay door is common to both images, but a comparison with the right image, which contains only real details, show that they are not real and that they are probably a processing artifact.”
One of the drawbacks of color sensors is that there is more noise in the image, so the image is less reliable than with black and white sensors. This is the reason that deep sky cameras often use black and white sensors. And so for imaging satellites like the International Space Station, Legault uses a black and white camera.
“It is more reliable, and you don’t need a color camera because the space station is colorless, except for the solar panels,” Legault said. “In addition, the monochrome sensor is much more sensitive to light, by 3 or 4 times. More sensitive means you have less noise.”
Legault’s main advice is just to be logical about what you are seeing in both raw and processed images.
“You need to look at the whole image, the consistency of the whole image, and not just one detail,” he said. “If I take an image that I say has detail on Jupiter’s satellites and on the same image I cannot even see the great red spot on Jupiter, it doesn’t work – that is not possible. The image must have an overall consistency and include details of an object larger than the one that we are interested in. So, if we see an image where someone is supposed to have an astronaut and a module of the space station, and a larger module is not visible or is completely distorted, there is a problem.”
Another piece of advice is to compare your image to another image taken by someone else — another amateur astrophotographer, a professional or even a space agency.
“If You have a photo of the space shuttle or the space station, for example, you can compare it to a real photo and see if all the details are there,” Legault said.
And if you still have questions about what you are seeing on your own images, Legault also suggests posting your images on astronomy forums so you can get the analysis and insights of other amateur astrophotographers.
“So, there are solutions to make sure that details are real details,” Legault said, “and as you get used to observing raw images and processed images, it will become easier to understand if everything is real, if just a part is real, or if almost nothing is real.”
But Legault’s main advice is not to over-process your images. “Many of amateurs take amazing, sharp images and using gentle and reasonable processing so that there are no artifacts.”
For more information and advice from Thierry Legault, see his website, especially the technical pages. Legault has written a detailed article for the March issue of Sky & Telescope on how to image the International Space Station.
You can also read our article on Legault’s astrophotography, published on March 1, 2012.
During one of the final space shuttle missions, photographer Thierry Legault traveled nearly 4,000 km across various locations in Europe to try and capture the shuttle docked to the International Space Station as the two spacecraft transited across the surface of the Sun.
“Essentially, I was trying to catch the clear sky so I could take images of an event that would last less than a second,” Legault said from his home in France.
This type of dedication to his craft, along with his attention to detail and quality has earned Legault the reputation as one of the top amateur astrophotographers in the world.
Amazingly, he started his astrophotography hobby — and his specialty of imaging objects in front of the Sun — just by chance. And now Legault has been shooting breathtaking images of spacecraft in orbit and astronomical objects and events for nearly 20 years.
“I began in 1993 with one of the first CCD cameras, the first year that CCD cameras were available for amateurs,” Legault said. “It was a wonderful time, because it was a time of pioneers, and it was a revolution after film.”
Intrigued by what could be done with digital equipment, he experimented by taking planetary and deep sky pictures and has now amassed a prolific portfolio of stunning images. In 2001 he took the first of the type of images he has become renown for.
“I took a picture of a plane in front of the Sun,” Legault recalled, “and it was published on APOD (Astronomy Picture of the Day), and so now I have taken many images of things in front of the Sun.”
In 2006 he took pictures of the space station and space shuttle side by side just as the shuttle undocked. It was published by newspapers around the world, including a double page in the Guardian, was shown on CNN and other news shows, and was everywhere on the internet.
“It was an incredible success, which was very surprising. This type of imaging is very fun for me, as I like the challenge,” Legault said. “But it is interesting how taking a picture of a spaceship in front of the Sun is really something for non-astronomers, but yet I never received so much interest for all the other astronomy images I have taken.”
Legault said he has received emails and letters from people around the world expressing how much they enjoy his transit images.
Living in the suburbs of Paris means there are plenty of lights to interfere with his astrophotography.
“Where I live is not a problem for taking pictures of some satellites, the Sun, the Moon and planets,” he said. “For deep space imaging and for the space station, I have to put everything in the van and drive 20-30 kilometers and go to the country; also for solar or lunar transits I have to go to the place where the transit is visible.”
For the STS-131 mission in May of 2010, Legault traveled to Spain, Switzerland, various parts of France, and for the STS-133 mission in February 2011, where he took the first-ever ground-based image of astronaut in spacewalk he drove to Germany, and to both the south and north of France, and between 3,000 and 4,000 kilometers.
All this driving and weeks of preparation is for an event that he never sees live with his own eyes, and usually lasts about a half a second. He uses CalSky.com to calculate the exact moment and exact location he will need to be to capture an event.
“For transits I have to calculate the place, and considering the width of the visibility path is usually between 5-10 kilometers, but I have to be close to the center of this path,” Legault explained, “because if I am at the edge, it is just like a solar eclipse where the transit is shorter and shorter. And the edge of visibility line of the transit lasts very short. So the precision of where I have to be is within one kilometer.”
Legault studies maps, and has a radio synchronized watch to know very accurately when the transit event will happen.
“My camera has a continuous shuttering for 4 seconds, so I begin the sequence 2 seconds before the calculated time,” he said. “I don’t look through the camera – I never see the space station when it appears, I am just looking at my watch!”
For a transit event, he gets get a total of 16 images – 4 images every second, and only after he enlarges the images will he know if he succeeded or not.
“There is a kind of feeling that is short and intense — an adrenaline rush!” Legault said. “I suppose it is much like participating in a sport, but the feeling is addictive. I did it with a friend two years ago and now he is addicted too.”
Legault added that when he succeeds, it is a very satisfying feeling.
But Legault is not keeping the adrenaline rushes all to himself; he willingly shares his knowhow and techniques.
His website provides a wealth of knowledge about his techniques and equipment
In 2005 he wrote a book (in French) called Astrophotographie, that has sold over 6,000 copies, and he is working on getting it published in English. The book provides information on how to image constellations, stars, comets, eclipses, the Moon, planets, sun, and deep-sky objects, in accessible, nontechnical language. Legault also gives practical advice on equipment and technique, with answers to problems faced by every beginner. He also co-authored another book, “New Atlas of the Moon” with Serge Brunier, and in the March 2012 issue of Sky and Telescope, Legault wrote a detailed article on how to take detailed, ground-based images of the ISS.
Tomorrow on Universe Today, Legault will share his advice for avoiding “bad” astrophotography.
I was waiting for this, and I know our readers have been looking forward to seeing astrophotographer Thierry Legault’s images of the ROSAT satellite as it heads towards its uncontrolled re-entry through Earth’s atmosphere to its ultimate demise. Legault took a series of images on October 16, 2011 from France and combined them into a video. The speed of the sequences is accelerated 3 times with regard to real time (30 frames per second vs 10 fps). The distance to observer is 275 km, with the altitude of the satellite at 235 km. Angular speed at culmination: 1.66°/s.
“It looks very steady, no sign of tumbling or flares like UARS,” Legault told Universe Today via Skype.
You can compare it to earlier images taken by Legault on September 23, 2011, below.
This remarkable video was taken with a 14” Schmidt-Cassegrain telescope using a specially made tracking system developed by Legault and Emmanuel Rietsch. You learn more about the system as Legault’s website.
Legault said he drove 100s of kilometers in order to capture ROSAT, and had to deal with clouds and fog before successfully imaging the satellite.
The latest prediction put out by the German Space Agency (DLR) has the ROSAT satellite re-entering sometime between October 21 and 24. This is a slightly narrower time window than the last prediction, which lasted until October 25. We’ll keep you posted on when and where the pieces of the satellite might fall. Legault told Universe Today that he is hoping ROSAT will provide some nice fireworks right over his location in France!
The video below, taken by Legault on September 23, 2011 at 04:36 UT shows ROSAT at an altitude of 284 km, with distance to observer at 458 km. Angular speed at culmination: 0.94°/s.
The huge Upper Atmosphere Research Satellite (UARS) will be plummeting to Earth in an uncontrolled re-entry this week, but here’s an incredible video from astrophotographer extraordinaire Thierry Legault who shot footage of UARS with his 14-inch telescope. Legault was in Northern France (Dunkerque) last week to attempt to capture views of the satellite, and had success on September 15, 2011 between 04:42:14 and 04:44:02 UTC, just 8-9 days before its atmospheric reentry, when it was at an altitude of only 250 km. The tumbling, uncontrolled nature of the satellite is obvious in this video, and various components are visible, such as the body itself and the solar arrays.
NASA has now refined its prediction for when this bus-sized satellite will fall to Earth. The 20-year-old defunct satellite now has a predicted re-entry Time of about 20:36 UTC on September 23, 2011, plus or minus 20 hours, according the the UARS Reentry Twitter feed. So, heads up!
This is a day earlier than previously anticipated. Pieces of the 6.5-ton satellite are expected to survive the fiery plunge and hit our planet, but NASA does not know exactly where. There was word today that increased activity from the Sun has hastened the decay of the satellite’s orbit.
Legault said his images show the satellite at a 316 km distance to the observer. The angular speed at culmination: 1.36°/s. The speed of the sequence is accelerated two times with regard to real time (20 fps vs 10 fps). The satellite is tumbling, perhaps because of a collision with satellite debris a few years ago.
Here is the equipment Legault used: Celestron EdgeHD 14” Schmidt-Cassegrain telescope (at a focal length of 8500mm) on automatic tracking system, as described on this page. Camera: Lumenera Skynyx L2-2.
Thanks to Legault for sharing his video and images with Universe Today! See more info at Legault’s website.
NASA says there are about 26 components that are big enough to survive and make it down to Earth, the largest weighing more than 150 kg (330 pounds.)
What are you chances of getting hit by debris? Nick Johnson, chief scientist with NASA’s Orbital Debris Program, said that numerically, it comes out to a chance of 1 in 3,200 that any one person anywhere in the world might be struck by a piece of debris. That might sound high, but if you factor in that there are 7 billion people on Earth and that a large part of Earth is covered by water, the liklihood is actually very small. The chance that any one person on Earth getting hit by debris has been estimated at about 1 in 21 trillion.
We’ll provide more updates on the UARS story. For those who would like to catch a last glimpse of UARS streaking across the night sky for yourself should check Heaven’s Above or SpaceWeather’s Satellite Tracker for flyby times in your area.
For more information about this satellite’s uncontrolled re-entry, see our earlier article detailing UARS.
It’s a great time to be an amateur astronomer! Nowadays, “backyard” astronomers armed with affordable CCD imagers, high-quality tracking mounts, inexpensive PC’s and the internet at their fingertips are making real contributions to Astronomy science.
How are people in their backyards contributing to real science these days?
Consider that in 1991, the Hubble Space Telescope launched with a main camera of less than 1 megapixel. (HST’s array was 800×800 pixels – just over half a megapixel). Currently, “off-the-shelf” imaging equipment available for a few hundred dollars or less easily provides 1 megapixel or more. Even with a “modest” investment, amateurs can easily reach the ten megapixel mark. Basically, the more pixels you have in your imaging array, the better resolution your image will have and the more detail you’ll capture (sky conditions notwithstanding).
With access to fairly high resolution cameras and equipment, many amateurs have taken breathtaking images of the night sky. Using similar equipment other hobbyists have imaged comets, supernovae, and sunspots. With easy access to super-precise tracking mounts and high-quality optics, it’s no wonder that amateur astronomers are making greater contributions to science these days.
One spectacular example of amateur discoveries was covered by Universe Today earlier this year. Kathryn Aurora Gray, a ten year old girl from Canada, discovered a supernova with the assistance of her father and another amateur astronomer, David Lane. The discovery of Supernova 2010lt (located in galaxy UGC 3378 in the constellation of Camelopardalis) was Kathryn’s first, her father’s seventh and Lane’s fourth supernova discovery. You can read the announcement regarding Ms. Gray’s discovery courtesy of The Royal Astronomical Society of Canada at: http://www.rasc.ca/artman/uploads/sn2010lt-pressrelease.pdf
Often times when a supernova is detected, scientists must act quickly to gather data before the supernova fades. In the image below, look for the blinking “dot. The image is a before and after image of the area surrounding Supernova 2010lt.
Before Kathyrn Gray, astronomer David Levy made headlines with his discovery of comet Shoemaker-Levy 9. In 1994, comet Shoemaker-Levy 9 broke apart and collided with Jupiter’s atmosphere. Levy has gone on to discover over twenty comets and dozens of asteroids. Levy has also published several books and regularly contributes articles to various astronomy publications. If you’d like to learn more about David Levy, check out his internet radio show at http://www.letstalkstars.com/, or visit his site at http://www.jarnac.org/
Rounding out news-worthy astronomers, astrophotographer Thierry Legault has produced many breathtaking images that have been featured here on Universe Today on numerous occasions. Over the past year, Thierry has taken many incredible photos of the International Space Station and numerous images of the last few shuttle flights. Thierry’s astrophotography isn’t limited to just the sun, or objects orbiting Earth. You can read more about the objects Thierry captures images of at: http://www.astrophoto.fr/ You can also read more about Thierry and the equipment he uses at: http://legault.perso.sfr.fr/info.html
Performing science as an amateur isn’t limited to those with telescopes. There are many other research projects that ask for public assistance. Consider the Planet Hunters site at: http://www.planethunters.org/. What Planet Hunters aims to achieve is a more “hands-on” approach to interpreting the light curves from the publicly available data from the Kepler planet finding mission. Planet Hunters is part of the Zooniverse, which is a collection of citizen science projects. You can learn more about the complete collection of Zooniverse projects at: http://www.zooniverse.org
Another citizen science effort recently announced is the Pro-Am White Dwarf Monitoring (PAWM) project. Led by Bruce Gary, the goal of the project is to explore the possibility of using amateur and professional observers to estimate the percentage of white dwarfs exhibiting transits by Earth-size planets in the habitable zone. The results from such a survey are thought to be useful in planning a comprehensive professional search for white dwarf transits. You can read more about the PAWM project at: http://www.brucegary.net/WDE/
One very long standing citizen project is the American Association of Variable Star Observers (AAVSO). Founded in 1911, the AAVSO coordinates, evaluates, compiles, processes, publishes, and disseminates variable star observations to the astronomical community throughout the world. Currently celebrating their 100th year, the AAVSO not only provides raw data, but also publishes The Journal of the AAVSO, a peer-reviewed collection of scientific papers focused on variable stars. In addition to data and peer reviewed journals, the AAVSO is active in education and outreach, with many programs, including their mentor program designed to assist with disseminating information to educators and the public.
If you’d like to learn more about the AAVSO, including membership information, visit their site at: http://www.aavso.org/
For over a decade, space enthusiasts across the internet have been taking part in [email protected] The official description of [email protected] is “a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI)”. By downloading special client software from the [email protected] website at http://setiathome.berkeley.edu/, volunteers from around the world can help analyze radio signals and assist with SETI’s efforts to find “candidate” radio signals. You can learn more about [email protected] by visiting http://setiathome.berkeley.edu/sah_about.php
The projects and efforts featured above are just a small sample of the many projects that non-scientists can participate in. There are many other projects involving radio astronomy, galaxy classification, exoplanets, and even projects involving our own solar system. Volunteers of all ages and educational backgrounds can easily find a project to help support.
If you’re like me, you were probably wondering if photographer Thierry Legault would have the opportunity to photograph space shuttle Atlantis in orbit during the final mission of the shuttle program. Regular UT readers will recall that Legault has taken several amazing images of the space shuttle and International Space Station from the ground with his specialized equipment, with many spectacular views of the spacecraft transiting across the face of the Sun or the Moon. It took a mad dash across Europe, but he was successful in chasing down the shuttle, capturing it crossing the face of the Sun several times, and once — just in the nick of time (above) — just minutes before the Atlantis’ final deorbit burn.
“I went to Czech Republik, then Germany and now I’m in Netherlands, on my way back to Paris,” Legault said in a note he sent to Universe Today. “The last transit has been taken Thursday morning, just 21 minutes before the deorbit burn, therefore there are chances that is the last image of a space shuttle in orbit.”
Earlier in the mission, he was able to catch the ISS and shuttle just 50 minutes after Atlantis undocked from the station, so his images capture historic moments of the final shuttle mission.
In addition, this stunning view shows Atlantis docked to the ISS:
Legault said this solar transit of Atlantis docked to the ISS was taken on July 15th from France (Caen, Normandy). Transit duration: 0.7s. ISS distance to observer: 520 km. Speed in orbit: 7.5km/s (27000 km/h or 17000 mph).
Four images of Atlantis crossing the face of the Sun taken on July 21st 2011 at 08:27:48 UT, and combined into one image. The images were taken just 21 minutes before Atlantis’ deorbit burn, from the area of Emden, NW Germany. Transit duration: 0.9s. Distance to observer: 566 km. Speed in orbit: 7.8 km/s.
Solar transit taken on July 19th at 7:17 UT from Czech Republik (North of Praha), showing Atlantis and the ISS side by side, 50 minutes after undocking. Transit duration: 1s. ISS distance to observer: 676 km.
Many thanks to Thierry Legault for sharing his images with Universe Today, and taking us along on the ride of his travels across Europe to capture the final space shuttle mission in a way that only he can!
Shhhh! Don’t tell anyone, but we’ve got pictures….. ground-based pictures of secret spy satellites in Earth orbit. We’re not revealing our sources, but … oh wait, I guess we might as well tell you. Even if we didn’t reveal our source, you’d probably guess that astrophotographer extraordinaire Thierry Legault — who has been sharing his wonderfully detailed ground-based images of the space shuttle and International Space Station with Universe Today – has been working on capturing other satellites in orbit as well. Legault and his partner in imaging crime, Emmanuel Rietsch have tackled the difficult task of tracking down spy satellites and then tracking them with a telescope. For imaging the shuttle and ISS, they developed their own design of a motorized mount outfitted with a computer program so it can slowly and precisely rotate in order to track and follow an object in Earth orbit with a telescope and video camera. Now they are able to image even smaller objects.
Above are images they were able to capture of three different spy satellites, including the X-37B spaceplane. More images and videos are available at Legault’s website.
Since October 2010, Legault has been using the autoguided mount, with the help of a DMK 31AF03 Firewire video camera mounted on the finder (FL 200 mm) and of the software Videos Sky, created by Rietsch, and then modified by Reitsch and Legault for fast tracking with the Takahashi EM400 mount.
The X-37B spaceplane now in orbit is the second of the two Orbital Test Vehicles launched by the US Air Force, launched on March 5, 2011. Reportedly, it will conduct experiments and tests for close to nine months and then autonomously de-orbit and land. Legault and Rietsch were able to image the spaceplane in late May of this year with fairly good results.
“I tried to get help to identify the real orientation of X-37B,” Legault told Universe Today via Skype today, “but on the contrary of the Keyhole and Lacrosse satellites, it’s not easy considering its complex shape with several wings.”
And the Air Force isn’t telling.
“Keyhole-class” (KH) reconnaissance satellites have been used for more than 30 years and are typically used to take overhead photos for military missions. Some of the keyhole satellites resemble the Hubble Space Telescope, but instead of looking out into space, it looks back at Earth. A similar type of spy satellites are the Lacrosse satellites, which are radar-imaging satellites.
But even with the tracking system, getting images of small satellites is not easy. “Despite this performing tracking system and hours of training on airplanes passing in the sky, keeping the space ship inside a sensor of a few millimeters at a focal length of 5000 mm and a speed over 1°/s needs a lot of concentration and training,” said Legault on his website.
The autoguiding and acquisition are done via a laptop with a double hard drive (one of which is a Solid State Drive – made with flash memory), enabling the precision of tracking of about one arc minute.
For security reasons, the sighting times for spy satellites are not published on an official website like NASA does for the shuttle and ISS. But with a bit of digging, Legault said others can try their luck at trying to spot these secret satellites.
“Orbital data are in the Calsky database,” Legault told UT, “therefore their passages are forecast as for the ISS. Generally, orbits are determined by amateurs, some of them are specialized in this activity, especially Kevin Fetter (and data are exchanged on the Seesat mailing list, owned by Ted Molczan).”
Legault is well-known for his images of the shuttle and ISS transiting the sun, but he said the accuracy of orbital data for the spy satellites is not sufficient for capturing a solar transit – and besides, these satellites are much smaller than the ISS and would appear as a small dark dot, at best.
“But for nighttime passages the data is sufficient,” Legault said. “Generally they are not visible with the naked eye or barely (except during flares), but they are easily visible with a finder.”
You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.