Tag Archives: NonGravitational

Press enter or click to view image in full size Trajectory of 3I/ATLAS with positions of the planets on October 31, 2025. (Credit: NASA/JPL) Yesterday’s report on a non-gravitational acceleration of 3I/ATLAS near perihelion (discussed here) stems from data obtained by the Atacama Large Millimeter Array (ALMA) which indicated that 3I/ATLAS was 4 arcseconds away in Right Ascension from where …

Press enter or click to view image in full size A stack of 134 images of the interstellar object 3I/ATLAS at perihelion, taken by the PUNCH’s WFI3 satellite on October 29, 2025. (Credit: kwalsh4a, Marshall Eubanks) By the date of its perihelion, 3I/ATLAS displayed the first evidence of a non-gravitational acceleration. The report (accessible here) was filed by Davide Farnoccia, …

Press enter or click to view image in full size Residuals in sky coordinates (Right Ascension [RA] and Declination [Dec]) of 3I/ATLAS relative to a gravity-based trajectory between May 15 and September 15, 2025. Averages and uncertainties are shown for 4,022 observations from 227 observatories worldwide, which were binned in time. The residuals are consistent with zero between May 15 …

Press enter or click to view image in full size (Image credit: Max Barry/Nation States) A simple way to distinguish a spacecraft from a rock is through its large non-gravitational acceleration. A natural icy rock like a comet is propelled by its mass loss. That mass loss can be observed through the cometary plume of gas and dust that surrounds …