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The Interstellar Visitor: 3I/ATLAS

• The object is officially designated 3I/ATLAS (also known as C/2025 N1 (ATLAS)), marking it as the third confirmed interstellar object to pass through our Solar System, following 1I/?Oumuamua (2017) and 2I/Borisov (2019) WikipediaReutersLive Science.

• Discovery & Trajectory:

  • Spotted on July 1, 2025, by ATLAS in Chile ReutersNASA Science.

  • It’s on a highly hyperbolic orbit, unmistakable evidence that it came from beyond the Solar System WikipediaSpace.

  • It’s moving at a tremendous speed—estimated at up to 130,000 mph (209,000 km/h) AP NewsLive Science.

• Closest Approach:

  • It will reach its perihelion, the closest point to the Sun, on October 29–30, 2025, coming within 1.36–1.4 astronomical units (AU)—roughly inside Mars’s orbit WikipediaReutersNASA Science.

• Earth Safety:

  • No threat to Earth: it will remain at least about 150 million miles (240 million km) away—roughly 1.6 AU ReutersAP NewsNASA Science.

• Size & Appearance:

  • The Hubble Space Telescope’s latest imagery refines the estimated nucleus size to around 5.6 km (3.5 miles), potentially as small as 320 meters, surrounded by a visible dusty coma and tail EarthSkyAP News.

• Why It Matters:

  • It’s the largest and fastest interstellar object detected so far, giving scientists a rare opportunity to study material from outside our Solar System Live ScienceSpace.

  • Some researchers (notably Avi Loeb) have speculated—even hypothetically—on intriguing origins, but the consensus remains that it's naturally occurring People.comChron.