Astronomers Map Ice Reservoirs Around 74 Nearby Stars in Landmark Survey

For the first time, scientists have captured detailed images of the frozen outskirts of 74 planetary systems around nearby stars, revealing vast belts of comets and ice-covered pebbles that could hold clues to how planetary systems like our own form and evolve.

The unprecedented survey, led by researchers at Trinity College Dublin, used arrays of radio telescopes in Chile and Hawaii to peer into these distant comet belts, which serve as cosmic deep freezers storing water and other compounds at temperatures as low as -250 degrees Celsius.

A New View of Alien Solar Systems

The study found remarkable diversity in these systems, challenging the traditional view of neat, ring-like belts similar to our own Solar System’s Kuiper Belt beyond Neptune. Instead, many of the observed systems feature wide disks of material, with some showing evidence of unseen planets through their gravitational effects on the distribution of debris.

“The images reveal a remarkable diversity in the structure of belts,” explains Dr. Sebastián Marino of the University of Exeter, who co-authored the study. “Some are narrow rings, as in the canonical picture of a ‘belt’ like our Solar System’s Edgeworth-Kuiper belt. But a larger number of them are wide, and probably better described as ‘disks’ rather than rings.”

Tracking Cosmic Evolution

The REASONS (REsolved ALMA and SMA Observations of Nearby Stars) survey captured systems at various stages of development, from newly formed stars to mature systems similar in age to our Sun. This range allowed scientists to track how these comet belts evolve over time.

“The power of a large study like REASONS is in revealing population-wide properties and trends,” says Professor Luca Matrà, who led the research at Trinity College Dublin. The team found that older systems contain fewer pebbles as their comets gradually erode, with this process happening more quickly in belts closer to their central stars.

Hidden Giants

The observations also provided indirect evidence of much larger objects lurking within these belts. By studying the vertical thickness of the debris disks, researchers concluded that objects ranging from 140 kilometers wide up to the size of Earth’s Moon must be present, even though they’re too small to detect directly.

Looking Forward

The study, published in Astronomy and Astrophysics, opens new pathways for future research. “The REASONS dataset of belt and planetary system properties will enable studies of the birth and evolution of these belts,” notes Dr. David Wilner from the Center for Astrophysics at Harvard & Smithsonian. He adds that follow-up observations using next-generation telescopes will allow scientists to examine these systems in even greater detail.

The findings could help astronomers better understand how our own Solar System’s comet belt formed and evolved, while providing insights into the ice reservoirs that might exist around other stars – a crucial factor in the potential for life beyond Earth.