Astronomers have detected a sugar molecule directly in interstellar space for the first time — in a cloud of gas and dust about 27,000 light-years from Earth. This matters because erythrulose may have formed even before planets were born. That means some complex organic substances, potentially important for future life, can appear already at the stage of star system formation.
Erythrulose is a sugar with four carbon atoms. Sugars had previously been found in meteorites and in samples from asteroid Bennu, but this is the first time such a molecule has been detected directly between the stars. Scientists suggest that it gradually builds up from simpler substances on ice-covered cosmic dust grains. Shock waves can then throw it into the surrounding gas.
The discovery does not prove that life came to Earth from space. But it supports another important scenario: young planets could receive some of the substances needed for complex chemistry already prepared — together with asteroids, comets and other cosmic material. In other words, the chemical "ingredients" of life may have appeared before the planets themselves.
