Produced by: Manoj Kumar
Astronomers recently doubled the count of “dark comets”—space objects resembling asteroids but behaving like comets—sparking fresh intrigue about their origins and role in shaping Earth.
In 2016, NASA’s Davide Farnocchia observed asteroid 2003 RM’s unexpected orbital shift. Its comet-like behavior, minus a visible tail, hinted at something new—an unseen cosmic phenomenon.
A year later, interstellar visitor ‘Oumuamua displayed comet-like acceleration without a tail. Its odd behavior reinforced suspicions about 2003 RM and deepened the dark comet mystery.
By 2023, seven known objects blurred the line between comets and asteroids. Astronomers named them “dark comets,” identifying their dual nature—silent, tail-free travelers with cometary traits.
Led by Darryl Seligman of Michigan State University, the latest study categorized dark comets into two groups: outer dark comets with eccentric orbits and inner dark comets on circular paths.
Outer dark comets, found beyond Jupiter, are large—spanning hundreds of meters. Their elliptical orbits resemble Jupiter-family comets, indicating ancient and possibly icy origins.
Inner dark comets dwell near Mercury, Venus, Earth, and Mars. Smaller and tens of meters across, they travel in nearly circular orbits, silently skimming through the inner solar system.
Seligman and Farnocchia propose that dark comets might hold clues to life’s origins. Could these shadowy objects have delivered essential life-sustaining materials to Earth eons ago?
What causes their anomalous accelerations? Do they contain hidden ice? With each discovery, dark comets challenge what we know about celestial bodies—and Earth’s cosmic history.