New Hubble data highlights motion anomalies in interstellar object 3I/ATLAS

New data from the Hubble Space Telescope highlight motion anomalies in the interstellar object 3I/ATLAS.

On December 27, 2025, Hubble captured a 170-second exposure using its Wide Field Camera 3 UVIS detector with the F350LP filter at a central wavelength of 0.5851 microns, as reported by USA Herald.

The raw image shows a bright nucleus surrounded by a halo with asymmetrical elongation, differing from standard cometary profiles according to USA Herald.

The exposure reveals abrupt brightness falloff along certain axes and extended emission along others, suggesting directional activity rather than uniform outgassing.

Earlier images from July and November also show off-center brightness peaks consistent with jet activity, as noted by USA Herald.

Hubble Observations Reveal Motion Anomalies in 3I/ATLAS

Asymmetry in Nucleus and Coma

Analysis of the December 27 frame shows that the nucleus appears as a compact, bright source, according to USA Herald.

The surrounding halo is not circular, and elongation favors one direction aligned with previously observed sunward anti-tail behavior, USA Herald reports.

Brightness gradients drop off unevenly along different axes.

The background star field appears as short streaks due to telescope tracking of 3I/ATLAS, confirming that the asymmetry is intrinsic to the object rather than caused by instrumental motion, as indicated by USA Herald.

Comparisons with earlier frames indicate that the central brightness peak is offset from the geometric center of the halo, consistent with a narrow emission feature or jet oriented close to the observer’s line of sight, USA Herald adds.

Double-Jet Structure

Harvard Professor Avi Loeb reported that Hubble images taken on December 12 and 27, 2025, show a double-jet structure in 3I/ATLAS.

Loeb explained that the more prominent jet is directed sunward and corresponds to the previously documented anti-tail. The secondary jet appears weaker and oriented opposite to the main jet.

Earlier observations from July showed a sunward jet approximately ten times longer than it is wide, with a 7-degree wobble around the rotation axis, Avi Loeb noted on his Medium blog.

Post-perihelion images indicate that the original Sun-facing pole now points in the same direction as the weaker jet, while the stronger sunward jet emerges from the opposite side, Avi Loeb added.

Jet Variability and Observed Motion

The relative brightness and projected shape of the two jets changed between December 12 and 27, 2025, which may correspond to rotational wobble or variability in the jet sources, according to Avi Loeb.

Observations indicate that the anti-tail jet brightens when the opposite jet weakens. The jets’ velocity profiles have yet to be determined from spectroscopic data.

Both jets are constrained in size, and there is no broad fan-shaped dust tail typical of many outbound comets, USA Herald reports.

Hubble frames confirm that 3I/ATLAS remains structurally active after perihelion despite its high velocity and interstellar origin, USA Herald adds.

Controlled Geometry of Emission

Hubble data show that 3I/ATLAS maintains a compact and directed emission pattern, according to the USA Herald. The images do not reveal a chaotic dispersal of material.

The directional emission aligns with earlier observations, documenting consistent structure and jet activity over multiple months, as noted by USA Herald.

Post-perihelion activity may differ from pre-perihelion patterns, with jets potentially launched from opposite sides or composed of material with varying particle sizes and velocities, according to Avi Loeb.

The December 27 Hubble exposure provides detailed observational data for 3I/ATLAS.

Raw frames enable the measurement of asymmetries, jet orientation, and brightness offsets without averaging or post-processing effects, according to the USA Herald.

These data contribute to a consistent record of the interstellar object’s motion and emission characteristics as it exits the solar system, Avi Loeb confirms.

Stay tuned for more updates.