A rocket obliterates a sundog
On February 11, 2010, as NASA’s Photo voltaic Dynamics Observatory (SDO) launched into space, its path took it straight by way of an atmospheric optical phenomenon often called a sundog. And within the video above, you’ll be able to hear observers gasp in shock when the rainbow-hued sundog disappears because the spacecraft passes by way of that a part of the environment. Certainly, it was an auspicious starting for a spacecraft that has aided in our understanding of our native star. And the launch additionally dropped at gentle a brand new type of ice halo and taught those that love and research sky optics new insights into how shock waves work together with clouds.
The 2023 lunar calendars are on sale. Order yours before they’re gone!
What’s a sundog?
A sundog is a shiny rainbow-colored spot within the sky, fashioned by refraction of daylight by way of plate-shaped ice crystals drifting down from the sky like leaves fluttering from bushes. Les Cowley of the web site Atmospheric Optics defined what’s occurring within the video at a post at Science@NASA:
When the rocket penetrated the cirrus, shock waves rippled by way of the cloud and destroyed the alignment of the ice crystals. This extinguished the sundog.
A column of sunshine
Within the video, hold a detailed look out for the luminous column of white gentle that seems subsequent to the Atlas V rocket that powered SDO’s 2011 launch. Though Cowley and different sky optics consultants understood why the sundog disappeared, they didn’t perceive the occasions that adopted, particularly that white-light column. Cowley stated:
A luminous column of white gentle appeared subsequent to the Atlas V and adopted the rocket up into the sky. We’d by no means seen something prefer it.
Cowley and colleague Robert Greenler at first couldn’t clarify this column of sunshine. Then they realized that the shock wave from the Atlas V organized the plate-shaped ice crystals. So Cowley defined:
The crystals are tilted between 8 and 12 levels. Then they gyrate in order that the primary crystal axis describes a conical movement. Toy tops and gyroscopes do it. The Earth does it as soon as each 26,000 years. The movement is ordered and exact.
Like it!
By the best way, NASA’s Photo voltaic Dynamics Observatory has now been observing the sun for 13 years. It’s one in every of a number of observatories that keep watch over our sun, a part of NASA’s Living with a Star program. The video beneath highlights a few of SDO’s achievements over the previous decade.
Backside line: On February 11, 2010, a solar observatory that was launched into space ripped aside a sundog because it handed by way of clouds, and created a brand new ice halo that amazed scientists.
Via Les Cowley’s Atmospheric Optics
Enjoying EarthSky so far? Sign up for our free daily newsletter today!
