The mystery of Earth's ghost moons and cosmic collisions

Space · Published 23 October 2026 Swipe more like this →

In short: For decades, scientists have debated the existence of eerie companions following our planet—objects that appear and vanish without explanation. While some call them 'ghost moons,' other parts of our solar system are revealing violent secrets involving massive collisions that mimic the birth of new worlds.

The concept of 'ghost moons' refers to mysterious objects spotted in Earth's vicinity that seem to haunt our orbit before disappearing. These elusive entities have sparked long-standing debates among astronomers regarding whether they are physical bodies or merely cosmic mirages. To date, the Moon remains our only confirmed permanent companion, but these fleeting sightings continue to challenge our understanding of local space.

While Earth's neighborhood remains mysterious, other systems are providing clearer evidence of celestial violence. Astronomers using the Hubble Space Telescope recently observed a nearby star system where an object initially thought to be a dust-covered exoplanet suddenly vanished. In its place, a different bright light source appeared, revealing that what was seen were not planets but glowing clouds of debris.

According to studies by Paul Kalas and Jason Wang, two distinct impacts between planetesimals—tiny stony bodies akin to asteroids—within the Fomalhaut star's planetary system produced these lights. Situated roughly 25 light-years away from our world, this area offered a primary live viewing of such an event beyond our own solar neighbourhood. These events occur over decades and offer a rare window into how planets form and what materials build new worlds.

Knowledge regarding these impacts remains crucial for initiatives involving planetary protection, including the Double Asteroid Redirection Test (DART). By studying the structure of asteroids through these violent impacts, scientists can better predict how to redirect objects that might pose a threat to Earth.

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