New research and updated modeling question a long-standing idea that comets delivered organic “building blocks” of life to Earth. Instead of surviving impacts, the fragile molecules that would be needed for life may not withstand comet strikes, reducing the likelihood that comets successfully seeded Earth with the relevant ingredients.
The outlets describe their work as revisiting century-old theories about how life’s chemical precursors might arrive on a young planet. Space.com emphasizes modeling that suggests these molecules would not survive the conditions of comet impacts. ScienceDaily reports Cambridge research concluding that comets likely traveled too fast and struck at angles unfavorable for molecular survival, making successful delivery “extraordinarily unlikely.” Both accounts shift the focus toward other sources, including asteroids or chemical processes on Earth, while also noting that other worlds like Mars may face different (but still slim) delivery odds.
