Scientists finally locate mysterious, missing material in space

Finding could have vast implications for much of what we know about planets

Scientists have finally located mysterious, missing material that appeared to have disappeared in space.

When stars are growing, there is plenty of carbon monoxide around. It glows brightly in the protoplanetary disks where new worlds begin life, and scientists can easily find it.

But much of it is missing, scientists have found over recent years. When scientists calculate how much carbon monoxide should be in those disks, and compare it with actual observations, something does not seem to add up.

But scientists appear to have solved the mystery. The missing material has been hiding, in ice formations within the disks themselves, researchers say.

“This may be one of the biggest unsolved problems in planet-forming disks,” said Diana Powell, a Nasa Hubble fellow who led the study. “Depending on the system observed, carbon monoxide is three to 100 times less than it should be; it’s off by a really huge amount.”

The mystery of the missing material is not only an important line of enquiry in itself. Carbon monoxide also tells us about other parts of the universe, so any problems with our measurement of that could in turn affect our understanding of disks and the planets they form.

“Carbon monoxide is essentially used to trace everything we know about disks — like mass, composition and temperature,” said Dr Powell. “This could mean many of our results for disks have been biased and uncertain because we don’t understand the compound well enough.”

To try and find the missing carbon monoxide, Dr Powell used models of how matter changes from one state to another, such as when a solid melts into a liquid. Such models are used to study distant planets, but helps us understand how ice forms on particles.

Adapting that model, Dr Powell looked to understand how carbon monoxide changes over time. She then compared the model with real observations of carbon monoxide in some disks that have been studied in detail – and they matched up.

Further work could use Nasa’s James Webb Space Telescope to further check the model. It could also actually detect that ice in disks, eventually.

The findings are described in a new paper, ‘Depletion of gaseous CO in protoplanetary disks by surface-energy-regulated ice formation’, published in Nature Astronomy.