Astrônomos have identified a new interstellar meteorite candidate in Nasa’s fireball database. The object, named Polar-IM, was detected on April 1, 2026. Analysis indicates that it came from outside Sistema Solar with a high statistical margin.
The event occurred at 02:13 UTC over Oceano Atlântico Sul, east of Argentina. Avi Loeb, of Universidade Harvard, and his postdoctoral fellow Richard Cloete led the study that details the bolide’s orbital characteristics.
Detecção recorded high polar velocity
Sensores of the Estados Unidos government captured the fireball at an altitude of 90.5 kilometers. The latitude was -41.9 degrees and the longitude was -54.7 degrees. The geocentric velocity included a polar component of 59.8 km/s, greater than the escape velocity of Sistema Solar.
The researchers transformed the reported velocity vector. Eles applied a hyperbolic two-body model to remove the gravitational influence of Terra. Depois, added the heliocentric velocity of Terra obtained from JPL Horizons.
The result showed a heliocentric speed of 51.73 km/s. The excess speed compared to Sol reached 30 km/s. The orbital inclination reached 89.4 degrees, almost perpendicular to the ecliptic plane.
Simulações Monte-Carlo reinforces interstellar origin
The team propagated measurement uncertainties across a million realizations. Eles used the post-2018 CNEOS empirical error model. Nenhuma simulation produced orbit linked to Sol.
Statistical confidence exceeded 99.9997%. The value corresponds to a margin of 12.82 sigma. Essa tag makes Polar-IM the most robust candidate ever registered in the CNEOS catalog for interstellar objects.
- Velocidade final polar: +47.09 km/s
- Energia estimated kinetics: equivalent to 0.086 kilotons of TNT
- Approximate Massa: 150 kilos
- Estimated Diâmetro: about half a meter
Comparação with other interstellar objects
Polar-IM adds to discoveries such as 1I/’Oumuamua, 2I/Borisov and 3I/ATLAS. Esses larger bodies have been observed by telescopes. Smaller Meteoritos, like this one, only reveal themselves when entering the Earth’s atmosphere.
Population Modelos predict that metric-scale objects intersect the internal Sistema Solar with a frequency detectable by monitoring networks. Polar-IM demonstrates that fireballs can expose these invisible visitors to telescopes.
Recuperação of material is challenging
The impact energy was modest. The high altitude suggests high fragmentation in the atmosphere. Qualquer surviving material would require drop ellipse calculation before any search.
Isso contrasts with the 2014 IM1 interstellar meteorite. Naquele case, Loeb led an oceanographic expedition that recovered molten fragments. Para o Polar-IM, the initial priority is to refine the trajectory reconstruction.
Próximos steps include independent validation
The authors recommend higher fidelity reconstruction. Tests should inflate uncertainties and sample tails of the error distribution. Também it is necessary to backpropagate the trajectory with a more detailed model of Terra-Lua-Sol.
Observações ground-based optical, infrasound, seismic or regional fireball networks at the exact date and time could confirm the data. The event reinforces the need to better monitor these phenomena.
The discovery paves the way to better understand the population of small interstellar objects. Ela shows that they arrive at Terra regularly enough to be picked up by existing sensors.
The study was completed quickly after initial identification in the CNEOS database. Loeb noticed the event while checking logs after another fireball on Boston. Cloete already had analysis tools from previous work.
Impacto for the astronomy of interstellar objects
Previous Pesquisas had already identified candidates at CNEOS. Polar-IM stands out for its speed polarity and statistical robustness. Ele outperforms other post-2018 events by margin above escape velocity.
The scientific community can use the data to calibrate models of atmospheric input and fragmentation. Futuras missions or improved networks will be able to recover samples of similar objects more easily.
The work is available in preprint and reinforces the role of public databases such as CNEOS in detecting rare phenomena.