CAMBRIDGE, United Kingdom, Oct. 28, 2026 - A University of Cambridge-led study in Scientific Reports finds comets were an unlikely route for delivering the chemistry of life to early Earth. Dr Richard Anslow was the lead author.

Computer simulations suggest most comets hit Earth too fast and too steeply for life's molecules to survive. In 54% of 100,000 simulated bombardment histories, no comet delivered enough hydrogen cyanide.

The study does not completely rule comets out. Asteroids, volcanoes and hydrothermal vents are suggested as alternative sources. Comets may also have delivered carbon molecules to Mars more easily than to Earth. César Menor Salván, commenting on the work, noted that it assesses only direct delivery of hydrogen cyanide.

Earlier sample return work found amino acids and DNA and RNA building blocks on asteroid Bennu, which had supported the idea of seeding from space.

Impact Insight. Speed and angle decide what an impact does, and they are also the numbers planetary defense teams calculate first for any incoming object. An impact does more than deliver energy: it can destroy almost all the fragile material the object carries.