The mysterious nature of 3I/ATLAS continues to baffle scientists, especially after the latest images. In recent observations, the space object was apparently spotted without a tail after passing close to the Sun. Typically, comets develop a tail as they approach the Sun, due to solar radiation and wind pushing gas and dust away from the comet.
Images taken by the R Naves Observatory in Spain on November 5 show 3I/ATLAS without a tail, despite expectations of significant outgassing. The object also brightened fivefold after perihelion and turned green, indicating possible diatomic carbon emission. 3I/ATLAS exhibits unusual motion, suggesting it may be shedding mass, but no tail is visible.
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Other scientists propose it might be a comet with an irradiated crust, altering its outgassing pattern. Meanwhile, Harvard astrophysicist Avi Loeb has argued that the object could be an alien spacecraft due to its unusual behaviour. While writing on Medium, he said that an estimated 13% of the nucleus should be visibly trailing the 33 billion-ton object. But that's not the case. The tail is not visible.
"For a typical comet, this should have resulted in a massive coma with dust and gas that would have been pushed by the solar radiation pressure and the solar wind to the shape of a typical cometary tail pointing away from the Sun. No such tail is visible in the new images from November 5, 2025," he wrote in Medium.
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Previously, during July and August 2025, the comet displayed a sunward jet (anti-tail) that is "not an optical illusion from geometric perspective", unlike familiar comets.
Loeb told The Post, "This offers a clean test of the nature of 3I/ATLAS in the coming weeks." "If 3I/ATLAS is a natural comet, it should be surrounded by a massive cloud of gas that carries at least 13 percent of the original nucleus mass."
NASA and the European Space Agency will monitor 3I/ATLAS as it approaches Jupiter on March 16, 2026.
