New Study Casts Doubt on Comets Delivering Life’s Building Blocks

WHO:

Mashable - The study concerns the possible origins of life’s building blocks on Earth.

Phys.org - The study examines the theory that comets delivered molecular building blocks for life on Earth.

WHAT:

Mashable - A new study says comets were probably not the source of life’s ingredients on Earth and suggests asteroids or Earth itself as possible sources.

Phys.org - A new study challenges the long-standing theory that comets delivered the molecular building blocks for life on Earth.

WHY:

Phys.org - The comet-delivery theory has persisted because comets are known to carry many of the molecules associated with life’s building blocks.

(UPDATED October 28, 2026 19:07 UTC)

A new study challenges the long-standing idea that comets delivered the molecular building blocks for life to Earth, finding they were probably not the source. The theory endured because comets are known to carry many molecules associated with life’s ingredients. The researchers suggest asteroids or Earth itself may instead have supplied those building blocks.