Hangzhou Light Show
By geoff | 12 July 2010 | 36 Comments
Something interesting apparently happened last Wednesday (7/7/2010) in the skies over Hangzhou, China. As regular Wonk-readers will quickly agree, trying to extract reliable information from regular media reports is difficult at best. Unfortunately, almost all the news reports of this incident that I have seen of it have something like “…UFO over Hangzhou…” in the title. That makes it even harder to believe the reports. It doesn’t help that some of the pictures seem inconsistent with each other. (Editors seem to believe that UFOs in the title means you can photoshop the photos as you like.)
Some of the most interesting photos remind me of the images of the reentry of the Japanese Hayabusa spacecraft. Here, the break-up of the object appears behind buildings reportedly in Hangzhou has a tremendously large apparent angle, making it very, very close to the city of Hangzhou. Too close, in my view, to be credible. ( See here for a discussion of “apparent angle.”) I believe these are photoshopped and I am ignoring them. (I freely admit it could be a mistake to dismiss these images but they just don’t seem credible even if they are extremely well done if photoshopped.)
Instead, let us consider some of the most obvious causes of what appears to have been seen. First, NASA does not list any satellite decays—a satellite reentering the Earth’s atmosphere after being in an established orbit—for that day, nor were there any predictions for satellites even near that date. So it is highly unlikely that the “UFO” was a reentering satellite. Furthermore, there were no satellites put into orbit that day so we can eliminate a lower stage reentering.
A DF-21?
The most credible image shows an arc streaking across the sky soon after (near?) local sunset. Assuming this is actually the “UFO” and that it really was taken at Hangzhou, then we can say some interesting things about its trajectory. First, it appears in the Northwest and the end of the trajectory (in this image) is roughly due North. Let’s make that a little more quantitative. At sunset (which happened at Hangzhou that day at 11:00 GMT), the Sun had an azimuth of approximately 300 degrees and remained in that approximate azimuth for a considerable time after setting; though, of course, its elevation continued to go negative. Therefore, the image—assuming it was not zoomed and that it was a typical cell phone camera—shows the end of the trajectory having an azimuth of at least 350 degrees. (That’s 10 degrees West of North.) The peak of the trajectory appears at an azimuth of about 335 degrees. I would say there is about a +/- 5 degree error in my heading estimates, depending mainly on where the Sun really is in the image. Of course, that does not have to be the actual point where the trajectory had its highest altitude. It could simply be the highest point on the apparent trajectory: the curve of the Earth’s surface and the angle the trajectory makes relative to the observer could make a different point appear to have the highest elevation in the image.
click on the image for a larger version
The red line represents the reconstructed line of sight for the “end” of the trajectory while the yellow line represents the reconstructed line of sight for the “peak” of the trajectory. The white line is the ground track for a hypothetical DF-21 trajectory.
The image above shows these reconstructed observation angles from Hangzhou; the red line represents the reconstructed line of sight for the “end” of the trajectory while the yellow line represents the reconstructed line of sight for the “peak” of the trajectory. I have added another line running roughly East to West from the Jiuquan Satellite Launch Center with a length of 1,800 km, roughly the range of a DF-21. Amazingly (perhaps an amazing coincidence) the halfway point of that trajectory corresponds roughly to the angle on which the apparent trajectory reaches its maximum. This peak appears to be about 25 degrees above the horizon in the image of the trajectory. Is that possible for a hypothetical trajectory so far away (~1,400 km) from the camera?
The apparent elevation of the peak of such a hypothetical DF-21 trajectory as seen from Hangzhou can be calculated from a simple geometric relationship as about 17 degrees. That is really amazingly close to the “observed” 25 degrees considering all the simplifications in the calculation I have introduced to make a quick calculation! So we certainly cannot rule out this possibility on geometric grounds alone.
Problems with a DF-21 Hypothesis
The major problem with a DF-21 hypothesis is that the peak of the trajectory occurs nearly 600 km above the Earth’s surface! So the arc we see in the image cannot be the trail produced by reentry heating. Perhaps we should rule a DF-21 launched from Jiuquan out on those grounds alone. But it is possible that continued discharge after burnout from the DF-21’s solid-propellant second-stage motor could be illuminated by the Sun if there was just the right geometry. Any other missile trajectory has to have the reentry much, much closer to Hangzhou. That creates lots of range safety issues and presumably are ruled out. (An errant missile trajectory would never have been allowed to get so close to such a large population center. All missiles, even SCUD combat missiles, have a self-destruct charge on board to prevent such large discrepancies from the planned flight path.)
So it seems to me that a DF-21 launch somewhere near Jiuquan and aimed at a point somewhere in the eastern Gobi desert is the most likely cause of this “UFO” even given the problem of illuminating the solid-motor discharge above the Earth’s atmosphere. Unfortunately, I doubt that we will learn anything new about the DF-21 from this image, given the uncertainty of where it took off, its heading, and its range.
A General Disclaimer
I have made a tremendous number of approximations and simplifications in this analysis in order to get a feeling for this event. Many of you will object to those and say more care should have been taken. I agree with you in principle but think such accuracy is unwarranted at this time considering the tremendous amount of uncertainty in judging which pictures are accurate and even what basic timing data to believe. Let me emphasize once again that this analysis assumes that the image at the top of this post is what caused the alarm in Hangzhou. I have no idea if that is the case. If some of the images I have discarded are really images of the phenomena, than this analysis’s assumptions are wrong at the start.
It is always hard to use media reports for quantitative analysis but particularly so for anything with UFO in the title. It seems that editors see that as a license for any kind of photoshopping they like. So, until better information is available, I think the most likely explanation is a DF-21.
Editor’s Note: Don’t even think about making a comment suggesting it was a real UFO, those comments will not get approved. This is a serious blog and is not interested in UFO theories. Get your own blog if you want to discuss that sort of thing.
Update (7/15/10)
The embedded video below shows both how difficult it is to get quantitative information off of the internet about “UFO” events and is a great example of a rocket plume in outer space. As an added bonus, there is a staging event at about 30 seconds. By the way, this is almost certainly a Progress-M launch from Biakonur.
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36 Responses to “Hangzhou Light Show”
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Allen Thomson | July 12, 2010
Any chance it was going in the opposite direction? If so, could you get it to go the vicinity of 40.45 N, 93.50 E ?
BTW, Google Earth seems to have come down with a case of screwed-upedness. One trusts they’ll get it fixed sooner rather than later.
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Mike | July 13, 2010
What about the Proton-M launch with EchoStar 15 on July 10, 2010 at 18:40Z. More information here:
forum.nasaspaceflight.com/index.php?topic=20840.0;all
and here coopi.khrunichev.ru/main.php?id=508 -
jim oberg | July 13, 2010
Since such reports really do often have clues about activities of interest such as the antimissile test in january’ i’ve been paying a lot of attention to this story. NONE of the photos seem to have any authentic connection to the event, which appears to have been sparked by an approaching aircrew seeing a bright twinkling light ‘above’ the runway. ATC could not locate it on radar and prudently waved off landing flights for a little while. Based on the runway alignment and the celestial sphere at the time, the most plausible explanation to me is just another typical pilot misperception of Venus — they actually do that a lot, the last famous airport case was Barnaul, Siberia, in 2001.
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Rwendland | July 13, 2010
I’ve looked at the theory it was the Shavit upper stage that launched OFEQ 9, by examining the orbit data at www.heavens-above.com.
OFEQ 9 passed in visible range at 20:31, but on a bearing of about 250 degrees – about 140 km SSE of Hangzhou Xiaoshan International Airport.
This newspaper says claims the event took place “around 9 pm” (13:00 GMT), which is at variance with your 11:00 GMT estimate.
So while the timing and distance is maybe plausible for an upper stage dropping from that orbit, the trajectory does not match your estimate from sun angle. So this is looking unlikely.
For the record, www.heavens-above.com observation data for Hangzhou (30.2550°N, 120.1690°E) China Standard Time (GMT + 8:00) says OFEQ 9 was observable three times that evening:
Date Starts Max-Altitude Ends
07 Jul 20:29:17 10 ENE 20:32:05 62 SSE 20:34:45 10 WSW
07 Jul 21:58:35 10 NE 22:01:19 31 NNW 22:03:51 10 WNW
07 Jul 23:27:42 10 NE 23:30:13 21 N 23:32:35 10 NWThe later two orbits were further to the north, at approx bearings 260 and 270 degrees, approx distances 600 km and 1000 km to the north.
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Rwendland | July 14, 2010
Geoffrey, this China Daily article gives more precise times, making it about 12:30 GMT (+- 5 mins I’d guess) for the event. Also competent observers report the object to be more like high flying object than a re-entry:
“A staff member at Xiaoshan Airport in Hangzhou said a twinkling object was first spotted over the city’s sky around 8:30 pm on Wednesday. However, the object did not show up on the airport’s radar.
Xiaoshan Airport was then closed at 8:45 pm over security concerns, and only resumed operation at 9:41 pm.” …
The twinkling object could have been a light below the horizon reflecting on an airplane flying very high, given good visibility in the sky, said Zhu Dayi, who works at the Shanghai Observatory, adding such phenomena usually happen around an hour after sunset.
“If the speed of the twinkling object is extremely high, it could be a military aircraft,” he said, “But no conclusion can be drawn now, as the information is limited.”
Coincidentally the event was to the minute when OFEQ 9 was nearly overhead, so it probably had an excellent view! Not that this implies it was the OFEQ 9 upper stage, which must have been on a different orbit by then.
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jim oberg | July 14, 2010
but was ofeq still illuminated? serious question.
the press report did not refer to motion across the sky — that apparently was filled-in-from-supposition material.
a non-angular-motion celestial object that shortly set still remains an attractive hypothesis untl more original eyewitness accounts surface.
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jim oberg | July 14, 2010
here are some recent links, and a revised comment:
abcnews.go.com/International/ufo-china-closes-airport-prompts-investigation/comments?type=story&id=11159531
Since such reports really do often have clues about activities of interest such as the antimissile test in january (link below) i’ve been paying a lot of attention to this story. NONE of the photos seem to have any authentic connection to the event (the June 30 .comet. video is of a Russian space rocket — too bad the reporter neglected to mention that ironclad ID). The event appears to have been sparked by an approaching aircrew seeing a bright twinkling light ‘above’ the runway. ATC could not locate it on radar and prudently waved off landing flights for a little while. Direct eyewitness testimony, and not news media garble, remains essential to obtain. But based on the runway alignment and the celestial sphere at the time, the most plausible conjecture to me is just another typical pilot astronomical misperception — they actually do that a lot, the last famous UFO closing an airport case was Barnaul, Siberia, in 2001.
jan 2010 story
www.msnbc.msn.com/id/34886772/ns/technology_and_science-space/
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Eric | July 20, 2010
Chinese aviation authorities shut down the airport for two hours. This wasn’t Venus, my God. People such as Jim posting on here have a serious problem with simple logic.
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Martin | July 20, 2010
The airport remained open until flight controllers realized the object was in the sky above the vicinity of their airspace. Why would the Chinese military test a ballistic missile along a trajectory which took it on a course above or anywhere near a busy international airport? And more to the point, why would they not close the airport before launch?
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Jim Oberg | July 20, 2010
Eric, it may shake your model of the known universe, but lots of very smart people — especially pilots — often misperceive Venus and other bright celestial objects as craft in the sky. The example of the Barnaul, Siberia, airport shutdown in January 2001 is germane — a flight crew ready for takeoff noticed a very bright light at the end of the runway they had taxied onto, interpreted it (prudently) as the landing lights of an approaching plane not under ATC guidance, and held their position. The light was in precisely the position that setting Venus would have been at. The aircrew subsequently reported the ‘UFO’ had vanished (Venus has set), and took off.
Leave the deity out of your expressions of sincerity and learn a little about human perceptual foibles, especially those of pilots, who have been shown in statistical studies to be among the WORST observers/identifiers of aerial apparitions, especially celestial objects. This may conflict with your instincts, but that’s a problem with your assumptions and your openness to real study results, not with the conjecture.
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Jim Oberg | July 20, 2010
The airport management decision process, as described below by an official’s on-the-record explanation, was straightforward and prudent. Observers (including aircrew) saw a light (or light — the number of the original Chinese is not clear to me) twinkling ‘above’ the airport (as viewed from their approaching aircraft), and were concerned about interference in the controlled airspace. ATC tower could not detect any a/c on radar, and so could not verify that what the observers saw was NOT somewhere overhead, so they followed prudent procedures and halted all aircraft movements through the ambiguous airspace.
The rest is popular panic, a collection of neat-looking visuals to feed the TV audience, and general news media freak-out. Standard stuff.
Without access to first-hand observer testimony, no conjecture can yet rise to the level of a decent testable hypothesis, but an awareness of the wide array of potential prosaic stimuli for such apparitions [and what has actually happened in the past of a similar nature, such as at Barnaul) is an important basis for sound brainstorming.
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Jim Oberg | July 20, 2010
Here’s what I meant to append:
“China Airport UFO”: Xiaoshan Airport Staff Interview
On www.ghosttheory.com/2010/07/16/china-airport-ufo-xiaoshan-airport-staff-interview
Ruan Zhouchang, spokesperson, Xiaoshan Airport in Hangzhou
[through interpretor]
“There was an unknown object seen in the skies over the airport. So according to our regulations we had to close the airspace. Aircraft movements were suspended from 8:45 PM to 9:41 pm. “Reporter: “Airport staff say the first reports of the UFO came in just after 8 PM from both air traffic controllers and civilians. The object at the center of the commotion, visible as a light in the sky, was captured in this photo. It may not look like much but it does not belong to a civilian aircraft. Nor does it match the flight plan of any aircraft supposed to be operating in the area at the time. ….
“Ruan Zhoucheng said there were few eyewitnesses because the incident occurred at night. When most staff members were not present and passengers were in the waiting hall.”
Ruan Zhoucheng [through interpretor]: “I heard that some of the passengers whose flights just landed saw the object which appeared as glowing light[s]. It was not a normal civil aviation flight. What it actually was, no one knows.”
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Anthony | July 20, 2010
The video that has been circulating predates the “UFO” stories in china – it was actually the Progress M-06M launch on June 30th as seen downrange in Kazakhstan. This video – www.youtube.com/watch?v=iruc2SXYHcU – was uploaded on the 30th, and the uploader identified it as the progress launch. All of the vids purporting it to be a UFO removed the original (Russian?) background audio.
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geoff | July 20, 2010
There have been a number of comments (that I have not approved because of their lack of general interest) that have pointed out the similarity between UFO and “Unidentified Flying Object.” All of these commenters seem to think they have found some sort of error in my posting and yet I am sure that they know exactly what I meant. I am sure that every one of them knows that by “real UFO” everyone understands that to mean little green men and aliens from outer space. So future word police can relax and know that they are far from the first to think that they are making a contribution by trying to impose their own concept of grammar.
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Dave Dickinson | July 21, 2010
Good job sleuthing this one out; we were suspicious as no good video of the object was produced, even in this age of flipcams. Most of the China images of the object looked like time exposures. The Kazakhstan vid was outstanding and reminded us of the recent STS-131 launch from Florida: astroguyz.com/2010/04/05/05-04-10-sts-131-shuttle-discovery-launch/
Thanks! -
ranel | July 21, 2010
just want to ask.. if
does a rocket or missile nowadays does not create smoke? instead they made light rays downward?
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Galrahn | July 21, 2010
Geoff,
Great stuff. What if the launch came from the Xichang Satellite Launch Center. Give serious thought to doing a model, because I think you would find your answer.
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marius | July 21, 2010
My Girlfriend was at that time in China for a businesstrip and told me about the UFO’s and delays on the airport. She took some pics and didnt realize that she actually shot 3 of them in one picture. If anyone has interest or know where i can send it in, please send me an email to mariuskoller@gmail.com
Not a joke and not photoshopped image!
Thanks,
Marius -
Benoit Racine | July 21, 2010
I have posted a commentary on your brilliant analysis on the Fortean Times UFO forum. I am trying to link the Hangzhu sighting – and your explanation of it – with the Urumqi sighting a week earlier (June 30, 2010). This last one could also have been a genuine sighting of the Kazakhstan rocket launch for the refueling of the International Space Station but it also could have been a Chinese DF-21 missile. This all depends of course on the exact trajectory of the Russian missile. Your opinion?
I also write a short history of the Internet fakes that have bogged down the investigation.
My post is on this page: www.forteantimes.com/forum/viewtopic.php?p=1004794&sid=8c3592b7dd693e5e98205d34fc60fa74#1004794
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Sean | July 21, 2010
The photo I saw was in the abc video here:
abcnews.go.com/International/ufo-china-closes-airport-prompts-investigation/story?id=11159531have you done any analysis of those? They were more interesting to me than the video. The lights shining down are curious. Is this a photoshopped image?
Thanks for the time you’ve put into this. It’s very interesting reading.
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baracine | July 21, 2010
These pictures have been declared hoaxes. They are simply time-lapse photos of a helicopter with a strobe light on top and a search light on the underside, probably hovering over the streets of Manchester, England. They were first used by the “Sun” newspaper in England and Fox News in the US (both owned by Rupert Murdoch) alongside the Hangzhou story.
See: www.aolnews.com/article/space-expert-china-ufos-likely-from-this-world/19560026
I am curious to know whether the Hangzhou sighting is related to the Urumqi incident of June 30, 2010. I have summarized the stories on this forum: www.forteantimes.com/forum/viewtopic.php?p=1004794#1004794
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Tom | July 12, 2010
Elsewhere, the “ufo” was reported to be traveling from East to West across the sky. One of the commenters at Information Dissemination (www.informationdissemination.net/) pointed out that if this were true then the object could be the upper stage of an Israeli launch vehicle reentering, since they have to launch to the West out over the Med.
An intel satellite that the Israelis launched last month apparently also has a ground track near to Hangzhou at the right time (again, from Info. Diss.).