Friday, February 28, 2014

What is wrong with this "picture of Aurora from Space"? Answer: everything!

Last night (27-28 Feb 2014) saw a geomagnetic storm that caused Northern Lights (Aurora borealis) in Europe at latitudes as low as 50 deg North. My home town was largely clouded out, but reports and images from elsewhere in the Netherlands as well as the UK, Ireland and Germany poured in.




As part of the buzz surrounding this auroral display, the image above was widely shared on Twitter. It purports to show aurora as imaged by "NASA", with some retweets adding that it was purportedly taken from the International Space Station.

Real images of aurora taken by NASA, ESA, Roscosmos and JAXA astronauts onboard the ISS do exist. But the image above is not one of them. It is completely fake, and it takes a knowledgeable person only a split second to recognize it as such.

Still, and rather surprisingly, even some professional Space and Astronomy organizations that should have known better initially fell for it and retweeted it.

So what is wrong with this image? What clear clues are there it is a fake? A deconstruction:

Exhibit #1:
One thing that immediately struck me was the lack of atmosphere. The image shows about 1/3rd of the Earth globe, but no clouds and no limb brightening. That immediately makes it clear that the earth globe shown is a digital rendering, where a cloud-free map of the earth has been digitally wrapped around the globe. It is not a true photograph of the earth from space.

Exhibit #2:
In addition to not showing an atmosphere, it does show something it should not show: bathymetry in the ocean.It shows the continental shelf as a lighter-coloured element in front of the Canadian coast. The continental shelf is often depicted as such on maps, but not actually visible as such on real satellite imagery. Again, this shows that a map of the earth including bathymetric elements was digitally wrapped around a globe: it is not a true photograph of the earth from space.

Apart from these two clear flaws, the whole image in fact clearly looks digitally rendered. The contrast between the daylight and nighttime parts of the earth is much too low too.

But, there is more, including the very damning exhibit #3:

Exhibit #3:
The auroral ring (actually an oval) is wrongly positioned on the globe. In the image, it is centered on the true Pole (the earth's rotational axis), in the Arctic sea. In reality, Aurora is however a phenomena connected to the Earth's magnetic field, and it therefore is centered on the Geomagnetic pole. The Geomagnetic pole is distinctly off-set from the true pole: it is located in Northern Canada, on Ellesmere Island.

Exhibit #4:
The auroral ring/oval is a complete ring on the image. In reality, the real auroral oval is much better developed on the night-time side of the globe than on the daytime side.

Exhibit #5:
Some retweets added that the image purportedly was made from the International Space Station. The ISS is however in a low 400 km altitude orbit. Aurora itself extends from 80 km to 200-300 km, during strong outburst up to 600 km altitude. In other words, the ISS orbits not much above, and in some cases even at similar altitudes as the aurora. It does not orbit as high above earth and the aurora as shown in this picture.

In fact, it is impossible to see this large a part of the Earth globe at once from the ISS. At anyone time the maximum footprint of the ISS in it's low orbit barely spans the N-American continent, as these images show:


click images to enlarge


The white filled circle is the area of the earth visible from the ISS. Clearly, an astronaut onboard the ISS cannot view as much as 1/3rd of the globe or more in one time, as the picture shows.

In fact, while an astronaut onboard the ISS could see a part of the auroral oval over Scandinavia or Canada, (s)he could never oversee the full auroral oval at once. This is only possible from a much higher orbit, a  Molniya orbit. So whoever insisted that image was taken from the ISS, got that part completely wrong too

Some sources say this image in reality is a digital 3D rendered graphic from an unidentified "NASA video". I doubt that NASA is the source: there is too much wrong with the graphic itself. Notably exhibit #3 and exhibit #4 are so sloppy from a scientific viewpoint, that I doubt such errors would be allowed in a NASA video.

update: it actually does come from a NASA video, to my surprise:

This issue of fake images popping up when an event gathers attention in the twittersphere, is interesting: someone, somewhere picked up that image and tweeted it with a BS story attached to it. This happens very often. Even more interesting is how it highlights the quick dissemination of misinformation through social media, even by people that should know better. I was rather surprised to see several persons and organizations that should have recognized it is a fake retweeting this image.

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2 Comments:

Blogger Roddy said...

When i posted it, I posted it in good faith. I saw it on Facebook and thought the image was lovely so I tweeted it. All hell broke loose. It made some people happy so I guess it's not all bad. No offence was meant, I apologise if some people to any.

28/2/14 20:55  
Blogger gav smith said...

Here's where the image comes from.
1 minute 22 seconds into this video of CGI animation.

http://youtu.be/i06fKeL2oJQ

The next time an image looks fake, just reverse google image it.

28/2/14 21:06  

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