March 30, 1999
Every candle on your cake is a tiny imitation of the stars that made you possible.
An Anomalous SETI Signal
Birthday · March 30, 1999
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published March 30, 1999. Credit: SETI League. A publication-date match, not a photo taken on your date. Independent of NASA.
No one knows for sure what caused this signal. The bright colors on the blue background indicate that an anomalous signal was received here on Earth by a radio telescope involved in a Search for Extraterrestrial Intelligence (SETI). A search for these signals is ongoing by several groups including volunteer members of the SETI League. Time labels the vertical axis of the above plot, and frequency marks the horizontal axis. Although this strong signal was never positively identified, astronomers have identified in it many attributes characteristic of a man-made satellite in low Earth orbit. Many unusual signals from space remain unidentified. No signal has yet been strong enough or run long enough to be unambiguously identified as originating from an extraterrestrial intelligence.
Image credit: SETI League