Comet 67p/Churyumov-Gerasimenko may have a long and complicated name but Twitter user landru79 certainly made sure people will remember it. On April 23, he tweeted a beautiful GIF compiling images of the comet, which the European Space Agency (ESA) has made public since March 22, and his work has caused somewhat of a sensation in the few hours since.
The short video reveals what seems to be a cosmic “snowstorm” raging on the surface of the comet and has been described by New Scientist as “a cosmic winter wonderland.”
Although the “snowstorm” depicted in the GIF is not actual snow, as it was soon made clear by astronomers commenting on the tweet, the short video is undeniably beautiful and it still gives us a sense of what it’s like to fly past a comet as it tumbles through space.
According to LiveScience, the GIF was processed from 25 minutes’ worth of images beamed back to Earth on June 2016 by ESA’s Rosetta probe, which chased comet 67P for a decade before finally deploying its Philae lander on the comet’s surface in 2014, ESA informs.
The footage used by landru79 to create the now-famous GIF was captured by Rosetta’s OSIRIS, or Optical, Spectroscopic, and Infrared Remote Imaging System, notes Gizmodo. Three months after these photos were taken, Rosetta’s instruments went dead and the small spacecraft crashed into the comet, thus ending its long and fruitful mission.
— landru79 (@landru79) April 23, 2018
Soon after landru79 tweeted his GIF, ESA’s senior science advisor Mark McCaughrean commented on the post, explaining what the “snowstorm” seen on comet 67P really is.
Most of the “snowfall” in the footage is actually made of cosmic rays, high-energy particles that register as streaks of light when they trigger the camera’s sensors. The rest of it is an illusion created by dust and ice particles that float above the 67P’s surface.
Pretty wild ???? My immediate guess is that this is foreground sun-illuminated dust quite close to the spacecraft & as it moves through that dust, it creates an illusion of snow" falling on Comet #67P kilometres away in the background. Cool though ???? @BadAstronomer
— Mark McCaughrean (@markmccaughrean) April 23, 2018
The footage also captures the stars behind the comet’s rocky cliffside, which McCaughrean was called in to identify. He replied with a comment revealing the stars are part of the Canis Major constellation.
Earlier today, landru79 tweeted a second GIF made from the same footage, in which the starfield in the clip is frozen in place to make it easier to spot the movement of the comet.
Si apilamos todo el set alineando con las estrellas de fondo se distingue mejor que son estrellas y q es polvo (olvidaos de rayos cósmicos ) #ROSETTA ???? OSIRIS #67P/CHURYUMOV-GERASIMENKO new albums ????–ROSETTA EXTENSION 2 MTP030– Miércoles 1 Junio 2016 all filters stacked???? pic.twitter.com/UyZ628JxKP
— landru79 (@landru79) April 24, 2018
Landru79 announced he also plans to make a full-color version of the GIF by using the color information transmitted by Rosetta.
Comet 67P was discovered in 1969 and has been spotted since then every 6.5 years, as it orbits the sun in an elliptical path between the orbits of Jupiter and Earth. To see it in flight, check out this animation by ESA.