A Romanian astronomer helps solve the mystery of water differences between meteorites and asteroids

Dr. Simon Anghel, a researcher at the Paris Observatory and the Astronomical Institute of the Romanian Academy, is part of a team of researchers who investigated why meteorites found on Earth contain significantly less water than the pristine samples brought back by space missions from asteroids like Bennu and Ryugu. Many researchers believe that asteroids like these, were important sources of water for early Earth.

Although astronomical observations indicate that most near-Earth asteroids should be carbonaceous, less than 4% of meteorites discovered on Earth are carbonaceous chondrites. For a long time, it was assumed that Earth's atmosphere acts as a filter, destroying these more fragile rocks during their incandescent entry as fireballs. However, research led by Dr. Patrick M. Shober (NASA, Paris Observatory), using data from several fireball observation networks (including the MOROI network, which covers Romania), suggests otherwise.

When these asteroids orbit close to the Sun, large temperature fluctuations cause them to crack and fragment before they reach our atmosphere. Thus, only the more resistant, and often 'drier', fragments survive the cosmic journey and atmospheric traversal to become meteorites. This natural selection occurring in space explains the observed discrepancy.

The published work can be found here: Nature Astronomy

Published on: Apr 16, 2025