Tag Archives: Avi

Press enter or click to view image in full size Hubble Space Telescope image of the interstellar object 3I/ATLAS on July 21, 2025. The brightness contours feature an elongation of scattered sunlight towards the Sun and not away from it as previously observed for solar system comets. The yellow and green arrows mark, respectively, the projected negative heliocentric velocity vector …

Press enter or click to view image in full size Deep imaging of the glow around 3I/ATLAS on September 7, 2025 displays a green color. (Credit: M. Jäger and Gerlad Rhemann) Until recently, all spectroscopic studies of 3I/ATLAS indicated a reddish color. The latest image of 3I/ATLAS from September 7, 2025 (reported by Michael Jäger and Gerald Rhemann here), suggests …

Press enter or click to view image in full size (Credit: PUNCHAN/ISTOCKPHOTO) A new paper (accessible here) that I co-authored with the brilliant graduate student at Vanderbilt University, Oem Trivedi, provides a framework for quantifying the Loeb Scale in the classification of interstellar objects as natural or technological. The recent astronomical discovery of a third interstellar object, 3I/ATLAS, following 1I/‘Oumuamua …

(Credit: shutterstock) How can we distinguish between the population statistics of interstellar rocks and a fleet of spacecraft that target that inner Solar system? The answer is obvious: by the spatial distribution of their trajectories relative to the Sun. Whereas rocks arrive on random trajectories initiated near their parent stars, spacecraft aiming to probe the habitable zone around the Sun …

Press enter or click to view image in full size (Credit: Adrian Mann) All spacecraft ever built by humans are smaller than 100 meters, the scale of a football field. They were all designed to explore the solar system and maintain their technological functions for less than a century. However, exploration of interstellar space requires long journeys, lasting millions to …

Press enter or click to view image in full size (Credit: BBC) Blind dates are exciting because they hold the potential for surprises, especially when dealing with an interstellar date partner of unknown origin. On October 3, 2025, the interstellar object 3I/ATLAS will pass within a distance of 29 million kilometers from Mars. At that time, the HiRISE camera onboard …

Press enter or click to view image in full size (Credit: Ciyavula) The biggest uncertainty about the interstellar object 3I/ATLAS involves the diameter of its solid-density nucleus. The flux detected by the SPHEREx space observatory at a wavelength of 1 micrometer from 3I/ATLAS on August 8–12, 2025 suggests a huge nucleus or alternatively an opaque dust cloud that scatters sunlight …

Press enter or click to view image in full size Deep images of 3I/ATLAS, taken by the Gemini South telescope on August 27, 2025. The different panels show images from short to long wavelengths in the u (upper left), g (upper right), r (lower left) and i (lower right) spectral bands, centered on wavelengths of 0.365, 0.467, 0.616 and 0.747micrometers, …

Press enter or click to view image in full size Logarithm of the nickel mass loss rate from 3I/ATLAS (vertical axis) as a function of heliocentric distance (horizontal axis). Blue circles show Very Large Telescope/X-shooter measurements of 3I/ATLAS and the black solid curve is a power–law fit to the data with a power-law index of −8.43±0.79. Colored symbols compare with …

Press enter or click to view image in full size Spectrally integrated flux maps for 3I/ATLAS observed by the NIRSpec instrument on the Webb telescope. Panel (a) shows the scattered sunlight around 3I/ATLAS on a scale of a few thousand kilometers (smaller by a factor of a hundred than the size of the CO2 plume detected by SPHEREx) at a …