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Radar Data Yields High-Resolution Views of Near-Earth Asteroid HQ124
On June 8th, with a radio source beamed at the asteroid designated 2014 HQ124 (less formally, "the beast") while two other telescopes tracked that beam's reflections, NASA was able to gather high-quality images of the object as it zipped by a mere 776,000 miles from Earth. (Some asteroids are closer, and a vast number of them could soon be better known, but none have allowed as good an opportunity for radar obvservation.) Astronomy Magazine's account adds a bit more detail: To obtain the new views, researchers paired the 230-foot (70m) Deep Space Network antenna at Goldstone, California, with two other radio telescopes, one at a time. Using this technique, the Goldstone antenna beams a radar signal at an asteroid and the other antenna receives the reflections. The technique dramatically improves the amount of detail that can be seen in radar images.
To image 2014 HQ124, the researchers first paired the large Goldstone antenna with the 1,000-foot (305m) Arecibo radio telescope in Puerto Rico. They later paired the large Goldstone dish with a smaller companion, a 112-foot (34m) antenna, located about 20 miles (32km) away.
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The first five images in the new sequence — the top row in the collage — represent the data collected by Arecibo and are 30 times brighter than what Goldstone can produce observing on its own.
I, for one, welcome our scientific overlords... may they continue to advance and outpace the hold on our people the religions have.
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The imaging technique can pick up features as small as 12 feet, on a 1200 foot long asteeroid
So thats about 100 pixels
Not exactly todays definition of high resolution when new tablets are coming out with 2560 x 1600 pixels
Looks like a mortar and pestle.
Giving the 776,000 miles number is of little value for most people. Comparing it to 1 Astronomical Unit (the average distance Earth-Sun = 92,955,807.3 miles) or the distance between the Earth & the moon (238,857 miles) makes it much more understandable.
Given that these infos are informative & not biased, I can see how Timothy didn't think to add them to the summary.
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There's also video of them successfully deflecting the asteroid: https://www.youtube.com/watch?...
I wasn't aware that a Teletubby was a standard unit of comparison. Maybe Le Système international d'unités can define degrees of similarity... "That asteroid is .7 Teletubbies in shape!"
I wonder what the SI unit for Teletubbies would be...
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NASA announced today that the latest geometric unit of measurement is the Teletubby. It will augment the square, rectangle, circle and oval.
and at only $0.25 for three ships, it was a bargain. The ship even had hyperdrive!
Although, it seems to me that -- if they had used both recieving dishes at the same time, we might have gotten some useful stereo images. Why didn't they do that?
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While checking out the video, I found myself realizing that it needed a soundtrack added. In particular, they should have added the sound effects from the original arcade version of Asteroids. That would have been awesome, and those forever top Asteroids champs ASS and FUK would have been so proud.
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The article says that these images are produced from radar scans. Why, then, does the asteroid look like it's illuminated from the side? If the asteroid was "illuminated" with a radar beam from an earth-based antenna, while the reflected radar waves were also detected using earth-based dishes, then shouldn't the asteroid look like it's illuminated head-on? Am I missing something here?
Back in ny early days as a lab techie I was running the optical processor that did the image-making post-processing for what I believe was the first "flyby" / "rotating target" synthetic aperture radar. (No significant intellectual contributions: I was running the machinery, rather than contributing to its design. Adjusting lenses, exposing and developing film, etc.)
Back in those days the computers weren't up to the amount of crunch needed. (This technique is essentially a two-dimensional fourrier transform with tweaks.) So we used laser light and lenses for the fourier transform, and photographic film for the input modulation and output capture. The original data was captured using a one-dimensional CRT with a solid row of fiber-optic light-pipes built into the faceplate. This was in actual contact with the recording film, transferrig the light from the phosphor inside the CRT without geometric distortions from lenses and such. The film was about four inches wide, and the servo capstain that advanced it was a critical component for accurate signal processing, as was the circuitry that linearized the sweep of the beam. The input plane of the optic processor held the film in a xylene solution between two optical flats, to eliminate phase distortion from roughness of the film's surface.
The nice thing about synthetic aperture radar is that the resolution is related to the radar frequencies and the relative motion of the antenna(s) and target, and is not dependent on the beam width of the antenna. (Well, wider beam width means you illuminate the target from a larger virtual antenna, sharpening the image.) Except for deltas, distance doesn't matter, either. You get the same resolution at tens of feet or interplanetary distances. Distance only comes into the pricture in terms of keeping the oscillators from drifting during the transit time of the beam, so you don't introduce varyimg phase errors when down-converting successive returned chirps.
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I understand that in relative terms, this sort of image is much better than anything else we can get in space, but when I see "high quality" image, I'm expecting something at least as good as an iPhone photo.