As 31/ATLAS swung close to the Sun, intense heat warmed its surface, causing frozen gases to vaporize and blast outward in jets. Those jets act like tiny thrusters, producing a continuous push that adds speed and nudges the comet off a purely gravitational track.
NASA has emphasized that while gravity cannot fully account for the motion, solar heating combined with uneven venting of gas and dust fits the data best. The agency has found no evidence of artificial propulsion.
Still, the behavior is unusual enough to demand close attention.
A Slight but Real Change in Course
Alongside the speed increase, NASA data show that 31/ATLAS deviated slightly from its expected trajectory after perihelion. The change is small and does not pose any danger to Earth—NASA has issued no collision warnings—but it is statistically significant.
“When a comet vents material unevenly, it can behave like a natural rocket,” one analysis notes, complicating long-term predictions.
For scientists, the key takeaway is not risk, but refinement. These subtle shifts highlight why non-gravitational forces must be built into models of future interstellar visitors.
Comparing 31/ATLAS to ʻOumuamua and Borisov
Because 31/ATLAS is only the third interstellar object ever observed, comparisons are inevitable.
- ʻOumuamua showed unexplained acceleration but no visible coma, fueling years of debate.
- Borisov behaved much like a classic comet, complete with a tail that matched expectations.
- 31/ATLAS sits somewhere in between: it shows a clear coma and tail yet also displays a “bizarre boost” in speed reminiscent of ʻOumuamua.Interstellar Comet 31/ATLAS Discovered by ALMA Reveals Alien Chemistry – USA Herald
NASA’s Stats and FAQ materials explicitly place 31/ATLAS in this lineage, helping scientists map the range of behaviors interstellar objects can exhibit.
New Images Reveal an Active, Complex Comet
Orbital data tell only part of the story. Images from multiple NASA missions are revealing a comet that is shedding gas and dust in intricate patterns.
