Overview

• The comet will pass about 29 million kilometers from Mars on October 3, offering a rare vantage point for close-up measurements.
• ESA’s Mars Express and ExoMars Trace Gas Orbiter are already targeting the object, with NASA orbiters and rovers available to assist.
• Scientists classify 3I/ATLAS as the third known interstellar comet and report no threat to Earth during its current passage.
• The object reaches perihelion near the end of October, and ESA’s JUICE spacecraft plans follow-up observations in November.
• Hubble data constrain the nucleus to no more than about 5.6 kilometers across and possibly as small as roughly 440 meters, with Earth’s closest approach expected in December at about 269 million kilometers.