By definition, scientists do not know what to expect from the interstellar object 3I/ATLAS – only the third ever detected in human history to come from beyond the boundaries of the Solar System, Futurism reported. But the surprises keep coming. The mysterious body, first observed in early July as it sped toward the Sun from deep space, has since drawn the attention of the global scientific community.

The most powerful telescopes – Hubble, SPHEREx, the Transiting Exoplanet Survey Satellite (TESS), and James Webb – have already set their sights on the object. While there is broad consensus among astronomers that it is a comet – a small icy body that releases gases as it passes near the Sun – the data reveal a far more complex picture, placing 3I/ATLAS among the most enigmatic objects ever observed.

SPHEREx and James Webb have found that the coma – the vast gas-and-dust envelope surrounding the comet’s nucleus – contains unusually high levels of carbon dioxide. In fact, the CO₂-to-water ratio is the highest ever recorded in a comet. Archival observations from TESS show that the object was bright and active even at a distance of six astronomical units from the Sun – far beyond Jupiter’s orbit, where comets are typically inactive.

Hubble revealed a “tear-shaped dust shell separating from the solid icy nucleus,” but without the distinct tail typical of comets. This prompted Harvard astronomer Avi Loeb to even suggest the hypothesis that the object could have been sent by an extraterrestrial civilization.

Its origin remains unclear. In a preliminary publication, an international team of scientists proposed that 3I/ATLAS may contain ices exposed to higher levels of radiation compared to those in the Solar System, or that it may have formed near the “CO₂ ice line” in its native protoplanetary disk.

As it passes through the inner Solar System, the object will make relatively close flybys of Venus, Mars, and Jupiter. Loeb has suggested that the Mars Reconnaissance Orbiter could take advantage of its passage within less than two million miles of the Red Planet, and a few months later the Juno spacecraft might intercept it as it approaches Jupiter. This could provide valuable data about its unusual nature before 3I/ATLAS disappears once more into the depths of space. | BGNES