The LookUp Project demonstrates the impact of bright satellites on
optical astronomy in real time. It provides insight into the
disruptive nature of such interference, the threat that low-Earth
orbit satellites pose to astronomy, and demonstrates how the
StealthTransit system protects astronomy and helps you coordinate with
the LookUp/StealthTransit team to safeguard your observations.
In the middle of Screen 1, we show Sensor 1 (green) of an astronomical
camera and the sky as seen through the “eyes” of telescopes located in
various places around the globe. For clarity, we show the impact of
satellites on a 1°×1.33° (3:4) field of view (green). The observation
direction of each telescope is chosen arbitrarily.
Screen 1, with a size of 4.5° x 6°, shows the movement of satellites
around the telescope’s field of view, as well as their trajectories.
To demonstrate the movement of satellites, we use current orbital
parameters known as TLEs (Two Line Elements) from the website
Space-Track.org (NORAD).
For illustrative purposes, we simulate a 300-second telescope
exposure. Satellites leave trails in the “images” just as they do in
real-life long-exposure astronomical photographs. After the exposure
ends, the website displays a number on Screen 1 for a couple of
seconds, indicating the degree of damage to the last image as a
percentage. This assessment is not strictly scientific, but it
provides an understanding of the danger that satellites pose to
optical astronomy.
The number of satellites in low Earth orbit is increasing every day.
According to forecasts, in a few years, an average of one satellite
will be visible per each square degree of the sky; the entire
celestial sphere covers about 41,000 square degrees.
Traditional digital methods for mitigating damage, known as
post-processing, do not effectively mitigate the impact of bright
satellites, such as BlueBird, which has the brightness of a full moon.
Along with removing satellite trails from images, post-processing
typically removes valuable scientific data. Predicting the timing of
satellite impacts on observations based on TLEs is inaccurate. TLEs do
not reflect satellite trajectories in real time. Therefore, protecting
astronomy from satellite impacts cannot rely on post-processing and
TLEs and requires special attention.
