Particle.news
Download on the App Store

MeerKAT Radio Detection Points to Water in Interstellar Visitor 3I/ATLAS

Two OH absorption lines at 1665 and 1667 MHz point to water-bearing gases in the object's coma.

Overview

  • South Africa’s MeerKAT array recorded hydroxyl absorption on Oct. 24 at 1665 and 1667 MHz with a velocity shift near −15.6 km/s, as reported in The Astronomer’s Telegram.
  • The OH signature arises from water photodissociation, providing direct evidence of water-related volatiles consistent with comet-like activity.
  • Researchers present the radio result as strong support for a natural origin, countering artificial-ship speculation even as some commentators continue to note anomalies.
  • High-resolution images from Nov. 5 showed little or no visible dust tail, an unusual optical profile that sustains scientific scrutiny of the object's behavior.
  • Follow-up is expanding with facilities such as Green Bank and Bonn, a safe closest approach to Earth of roughly 1.8 AU expected on Dec. 19, and a planned Juno low-frequency search near Jupiter on Mar. 16, 2026.