WG3K   > ANS      16.11.25 04:45l 37 Lines 1901 Bytes #198 (0) @ AMSAT
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Subj: Comet Photos Plagued by Satellite Streaks
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Recent months have seen space fans revel in a wealth of spectacular
astrophotography depicting the evolution of Comet Lemmonâ€Ös glowing coma and
twisting tail as it journeyed through a Northern Hemisphere night sky
swarming with satellites.

While many photographers opted to post sanitized views of Comet Lemmon,
others intentionally compiled their images to reveal the incredible number
of satellites that crossed the night sky over the course of multiple
exposures.

*A composite image of Comet Lemmon revealing where bright pixels were
rejected by an image-stacking algorithm. (Image credit: Dan Bartlett via
Space.com)*

“Photographically, if someone is attempting to take a single image of a
target and needs the image to be ‘cleanâ€Ö â€ö free of manmade objects â€ö well,
that image is nearly impossible to obtain,� astrophotographer Dan Bartlett
told Space.com in an email. “Every single subframe I take (prior to
stacking) now contains at least one, and usually more than one satellite
streak.�

There are currently about 13,000 operational satellites orbiting Earth, of
which about 8,900 are SpaceX Starlink craft. This number is set to
exponentially increase, with SpaceX alone aiming to orbit up to 42,000 of
its internet-beaming spacecraft, while competing companies aim to add
thousands more satellites to their own “megaconstellations.�

Astrophotographers combat satellite streaks by capturing a multitude of
short exposures over the course of a single session. The images are then
combined and subjected to an algorithm that determines a median value for
each pixel before rejecting outlier pixels with values that exceed set
parameters.

*[ANS thanks Space.com for the above information. Read the full article at
https://www.space.com/stargazing/astrophotography/comet-lemmon-photos-are-plagued-by-satellite-streaks-heres-how-amateur-astronomers-face-the-problem.]*


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