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night flight

time lapse sequences of SOFIA flight #298

Date:18.05.2016 Time:Start of each sequence in UT:
7:24, 8:01, 9:14, 10:43, 11:10
Exposure:1.6 s each, 2 s interval Field:max. 73o x 45o
Camera:Nikon D3 Optics:24mm f/1.4
Place:US West Observer:Till Credner

© copyright: the sky in

Flying on board of the Stratosphere Observatory for Infrared Astronomy (SOFIA) was a great opportunity for imaging the night sky from 40000 feet height. The Boeing 747 carries a 17 ton telescope in the back. But also a normal camera peeking through a planes window might give some interesting images. The light pollution from the ground is passing by. The moon was almost in its full phase. Nevertheless, the sky appears dark and a bright milky way can be seen. Planets Mars and Saturn shine brightly in the constellation of Scorpius (upper right).

flight plan

With the given times above and the flight plan you and your students might find some answers to the following questions:

  • Why are the clouds so bright?
  • Why is the video so shaky?
  • What is SOFIA and the big telescope doing to reduce this?
  • Measure and calculate, how long the five time lapse sequences were in reality. The video plays with 25 fps (frames per second).
  • What is the acceleration factor of this time lapse?
  • When did SOFIA change the direction? Is this according to the flight plan?
  • With the flight plan and Google Maps you may identify some cities.
  • Try to determine roughly the cruising speed of the airplane.
  • Why is the horizon inclined at the last sequence? The camera did not change.
  • What is happening with the image brightness at the end? In which direction are we looking?
  • Artificial light shining directly from the source into the sky and to SOFIA is called light pollution. This upward light can't fullfill any lighting purpose and therefore is wasted energy. Furthermore it is harmful to nature. What do you think are the visible sources of light pollution in the video?
  • Light pollution can brighten the sky so much that you only can see the brightest stars and no milky way. Why isn't this a problem for SOFIA?

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More impressions from these flights.