The coexistence of ground-based radio observatories and artificial satellites in low-earth orbit requires ongoing negotiation. Although certain frequencies are protected for astronomy research, it is becoming increasingly apparent that the megaconstellation Starlink is emitting unintended radiation at key observational frequencies. Dylan Grigg and co-authors surveyed the appearance of these satellites in observations with the Engineering Development Array 2 (EDA-2) — a prototype for the Square Kilometre Array Low (SKA-Low) — and demonstrated their ongoing emission across the SKA-Low observing bandwidth.
The authors conducted 24-h observations at 29 unique frequencies and detected satellites by modelling their expected positions over time and assessing fit quality; a satellite was considered identified if it was detected at five or more distinct time steps. In total, 1,806 unique satellites were identified, with their occurrence rate depending on frequency and peaking in the 161.7 and 170.5 MHz channels, where satellites appeared in 30% of all images. The latest generation of satellite models dominated detections, reflecting the rapid expansion of the Starlink megaconstellation and their continued interference with astronomy (P. Woods. Nat. Astron. 8, 1212; 2024). The mean flux density of the emission was found to be 93 Jy beam−1, which is five orders of magnitude above the noise level required to characterize the epoch of reionization (a major science goal for the SKA).