Holidays from the Heights

Only two sets of people can fly around the entire world in one night. One is rumored to reside at the North Pole; the others live on the International Space Station (ISS). And for all of them, the night-lit view of the planet is simply extraordinary.

Bask in the warm light of your computer screen and sample the festive sights of the season from the perspective of satellites and space station residents.

In November and December 2011, professional and amateur astronomers reveled in observing a sun-grazing comet that dove close to the Sun and survived for a return flight back to the outer solar system. Astronauts on the International Space Station (ISS) enjoyed their own surreal view of the comet as it appeared on Earth’s horizon on the day of the solstice.

ISS030-E-014350ISS Commander Dan Burbank captured a series of digital photographs of Comet Lovejoy on December 21, 2011, as it rose above Earth’s limb. The ISS was passing from eastern Australia southeast toward New Zealand, between 17:35:50 to 17:43:02 Universal Time (6:35 to 6:43 a.m. local time on December 22). Those still images were compiled into a time-lapse video that you can view here. In an interview with WDIV-TV, Burbank described the moment as “the most amazing thing I have ever seen in space.”

Note how the tail of the comet points away from the Sun even as the comet itself is moving in the same direction, away from our star. Every comet has two tails, one of ice and dust, the other of ions, or charged particles. The heat and pressure of sunlight sloughs off the ice and dust, pushing it away from the Sun. Likewise, the solar wind strips ions off of the comet surface, though not necessarily in the same direction as the tail of debris and ice. The ion tail is not visible in this image.

The comet, officially designated C/2011 W3 (Lovejoy), was discovered by Australian amateur astronomer Terry Lovejoy on November 27, 2011. It belongs to a group of comets known as the Kreutz sungrazers, which are thought to be pieces of a much larger comet that broke up centuries ago. The comets are termed sungrazers because their orbits take them quite near—and often into—the Sun.

Comet Lovejoy is remarkable for diving through the superheated solar corona (atmosphere) to within 120,000 kilometers of the Sun’s surface and surviving the encounter. The event was recorded by five NASA and European spacecraft.

In the ISS image above, you can also see green and yellow airglow paralleling the Earth’s horizon line (or limb) before it is overwhelmed by the light of the rising Sun. Airglow is the emission of light by atoms and molecules in the upper atmosphere after they are excited by ultraviolet radiation. In the video, small intermittent flashes of white lightning discharges also are visible over Earth’s surface.

Astronaut photograph ISS030-E-015491 was acquired on December 22, 2011, with a Nikon digital camera, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 30 crew. The image has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Michael Carlowicz, NASA Earth Observatory, and Melissa Dawson and William L. Stefanov, Jacobs/ESCG at NASA-JSC at NASA-JSC.




ISS025-E-09858 Nile River Delta at night


ISS032-E-017547 Istanbul at night


If you happened to be flying a reindeer-harnessed sleigh through the sky on December 24th and 25th, the view might look pretty similar to what the ISS crew witnessed. You can follow such a holiday flight by visiting the NORAD tracking page, where satellites, fighter jets, and radar stations provide airborne reconnaissance for the jolly sleigh-rider in the red suit—who has special clearance one night per year.