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Office of the Secretary of Defense: 027_Satellite_Flaring_Paper

Department of Defense. Office of the Secretary of Defense. · 2023 · 18 pages · text from the file's own layer

This information paper from the Department of Defense's All-domain Anomaly Resolution Office (AARO) is dated December 2024 and was released in full in February 2025. It explains how sunlight reflecting off Starlink and other low Earth orbit satellites produces bright flares and satellite trains that observers can mistake for UAP. It gives step-by-step methods for predicting flare windows from the ground and from aircraft. It concludes that lights reported by an airline pilot near Gallup, New Mexico, in October 2022 were very likely satellite flares.

All-domain Anomaly Resolution Office (AARO)
9
Error! Reference source not found.These numbers will vary for satellites with different orbital
altitudes, but these guidelines are suitable for the current family of Starlink satellites.
Step-by-step Process to Estimate Location of Flare Window
We now have enough information needed to estimate the look angles to observe Starlink flares,
specifically the sun’s elevation angle and satellite elevation angle. One can use the following
process to predict the flare window’s azimuth and elevation. Table 1 provides a template for
recording your observation.
Note the following information:
1. Choose the observation location (latitude and longitude).
2. Select the year.
3. Select the date.
4. Predict the Sun's azimuth at the chosen time, date, and location by entering the information
from steps 1-3 into an online calculator of your choice. Two example calculators are
https://www.suncalc.org/ or https://www.timeanddate.com/sun.
5. Use the slider bar at the top of the page for suncalc.org or the expandable tables on
timeanddate.com to find the time and azimuth after sunset when the Sun's altitude is -38°.
6. Record the Sun's azimuth and the local time of day.
7. After recording information from step 6, use the slider bar at the top of the page for
suncalc.org or the expandable tables on timeanddate.com to find the time and azimuth after
sunset when the Sun's altitude is -46°.
8. Record the Sun's azimuth and the local time.
Table 1: Example template for recording estimated azimuth and times for Starlink flare windows.
Observation Site Latitude
NOTES:Longitude
After sunset Before sunrise
Date Time (L) Sun Altitude Azimuth Look
Angle
Date Time (L) Sun Altitude Azimuth Look
Angle
-38° 10° -46° 0°
-46° 0° -38° 10°
Measured Values of Satellite Flare Measured Values of Satellite Flare
Date Time (L) Flare
Azimuth
Flare
Elevation
Date Time (L) Flare
Azimuth
Flare
Elevation
9. Repeat steps 4 through 8 for the following day. Find the times and azimuths for the Sun
before sunrise at -38° and -46°.
10. Using the information in the table, perform the observations and record the measured
values in the table.
The scenario below illustrates this process by working through an example.
Scenario027Page determined to be Unclassified
Reviewed by Chief of Staff, AARO
IAW FY24 NDAA, Section 1841(a)(1)(C)
Date: 2/14/2025

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Official release, from the nara collection. The PDF is mirrored here; the original link is above. 18 pages are in the text index: search them above, or from the library's search.