The Truth Behind This Amazing Video from the Surface of a Comet
Look at this amazing GIF. That snowy-looking scene wasn't captured on Mount Everest, or in some canyon in Antarctica. That's the view from a lander on the surface of a comet.
Remember Rosetta? That comet-chasing European Space Agency (ESA) probe that deployed (and accidentally bounced) its lander Philae on the surface of Comet 67P? This GIF is made up of images Rosetta beamed back to Earth, which have been freely available online for a while. But it took Twitter user landru79 processing and assembling them into this short, looped clip to reveal the drama they contained.
As several astronomers and casual observers pointed out in the replies to landru79's original tweet, the "snowstorm" depicted almost certainly isn't a true snowfall of the sort experienced on Earth and other planets. Instead, there are likely two or three different phenomena creating the snowy effect.
Up close to the camera, dust particles backlit by the sun are likely moving around, mimicking the look of snow on Earth. Cosmic rays may also be creating snow-like artifacts on the images. And those dots in the background, that appear to be falling straight down and disappearing behind the cliff? Those appear to be stars, which look like they're falling because the comet is rotating as it orbits the sun every 6.5 years.
The clip has also been sped up a great deal, enhancing the drama.
According to the creator, the first frame of the GIF is an image shot June 1, 2016, at 3.981 seconds past 5 p.m. UTC (1 p.m. Eastern). The last frame is an image shot at 17.017 seconds past 5:25 p.m. (1:25 p.m. Eastern) on the same day. That means that a bit more than 25 minutes worth of action is compressed into this short clip, so everything appears to be moving much faster than it did in reality.
But none of that is to detract from what landru79 pulled off here, which captures something close to the drama of standing on the surface of a far-away comet (though we've never tried that).
Landru79 said that in their next project they will use the color information Rosetta beamed home to make a full-color version of the GIF. Live Science can't wait to see it.
Update, 12:23 p.m. Eastern:
Landru79 posted another GIF on Twitter, which freezes the starfield in the clip in place, making it clearer that the comet is moving but the stars are mostly staying still.
Originally published on Live Science.