New telescope observations revealed streams of gas and dust, called jets, blasting out in rhythmic bursts every 16.16 hours precisely, much like a steady heartbeat.

Moreover, this pulsing makes the object’s overall glow brighten and dim by 20 to 40 percent in a clean, repeating cycle, which some have claimed suggest 3I/ATLAS is not a naturally-occurring comet.

https://www.dailymail.co.uk/sciencetech/article-15345507/Mysterious-heartbeat-interstellar-object-3I-ATLAS.html