VLT snaps image of double asteroid zipping past Earth
The Very Large Telescope (VLT) in Chile was successfully able to photograph the double asteroid that flew past the Earth on May 25 at a distance of 3.2 million miles and a speed of 43 thousand miles per hour.
The left image on the right is the raw image, while the right image is their reconstruction after applying adaptive-optics (AO) to the raw image. From the press release:
Bin Yang, VLT astronomer, declared “When we saw the satellite in the AO-corrected images, we were extremely thrilled. At that moment, we felt that all the pain, all the efforts were worth it.” Mathias Jones, another VLT astronomer involved in these observations, elaborated on the difficulties. “During the observations the atmospheric conditions were a bit unstable. In addition, the asteroid was relatively faint and moving very fast in the sky, making these observations particularly challenging, and causing the AO system to crash several times. It was great to see our hard work pay off despite the difficulties!”
To put it mildly, that right image is a fantasy. Astronomers love to tout the wonders of adaptive optics, but no matter how good it might be, it still is garbage-in-garbage-out, a computer simulation based on their guess at what the object would look like if there was no atmosphere in the way. In this particular case, they are being especially fantastic, and guaranteed to be wrong. It is impossible for them to extrapolate such minute surface details from the fuzzy image on the left.
Still, getting an image of this asteroid as it zipped by at that speed using such a large telescope is an achievement, and bodes well for the use of ground-based astronomy of near Earth asteroids.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The Very Large Telescope (VLT) in Chile was successfully able to photograph the double asteroid that flew past the Earth on May 25 at a distance of 3.2 million miles and a speed of 43 thousand miles per hour.
The left image on the right is the raw image, while the right image is their reconstruction after applying adaptive-optics (AO) to the raw image. From the press release:
Bin Yang, VLT astronomer, declared “When we saw the satellite in the AO-corrected images, we were extremely thrilled. At that moment, we felt that all the pain, all the efforts were worth it.” Mathias Jones, another VLT astronomer involved in these observations, elaborated on the difficulties. “During the observations the atmospheric conditions were a bit unstable. In addition, the asteroid was relatively faint and moving very fast in the sky, making these observations particularly challenging, and causing the AO system to crash several times. It was great to see our hard work pay off despite the difficulties!”
To put it mildly, that right image is a fantasy. Astronomers love to tout the wonders of adaptive optics, but no matter how good it might be, it still is garbage-in-garbage-out, a computer simulation based on their guess at what the object would look like if there was no atmosphere in the way. In this particular case, they are being especially fantastic, and guaranteed to be wrong. It is impossible for them to extrapolate such minute surface details from the fuzzy image on the left.
Still, getting an image of this asteroid as it zipped by at that speed using such a large telescope is an achievement, and bodes well for the use of ground-based astronomy of near Earth asteroids.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I’m having a hard time not thinking “fraudulent” is the best description of that AO-processed image. I’ve seen some amazing things enabled by adaptive optics, but this reeeeeeally doesn’t smell right.
… then I see there is another link on the ESA site describing the image on the right as an artist’s impression, which I can totally believe. So is the image on the left the actual AO-enhanced image?
https://www.eso.org/public/images/eso1910a/
Maybe they’ve been “inspired” by TV shows?
https://www.youtube.com/watch?v=Vxq9yj2pVWk
Matt in AZ asked: “So is the image on the left the actual AO-enhanced image?”
My understanding of adaptive optics is that the image recorded in the camera is the post-adaptive image. The adjustments are made within the telescope and are not made to the collected data.
Once an image is formed, that is all the data that there is. In order to enhance an image, either guesswork has to be made that makes assumptions about, for instance, the data within adjacent pixels, or multiple images have to be processed together so that the additional data can be used to make better guesses about the pixels.
Edward is correct. Adaptive Optics involves warping the optical components, usually the mirror, to attempt to eliminate distortion.
https://en.wikipedia.org/wiki/Adaptive_optics
Matt in AZ, and Bob Z., are both correct. Here’s the description from the ESA website. The right-hand image is pure fantasy, and a disappointment for me that they’d publish such an image.
“The left-hand image shows SPHERE observations of Asteroid 1999 KW4. The angular resolution in this image is equivalent to picking out a single building in New York — from Paris. An artist’s impression of the asteroid pair is shown on the right.”