Astronomers have found new evidence of just how diverse the chemistry can be in the gas-and-dust disks from which planets form. Observations with the ALMA radio telescope revealed methanol containing a heavy isotope of hydrogen around one young star, as well as unexpectedly widespread methanol microwave emission in systems with young low-mass stars. These results will help determine which chemical substances are present in future planetary systems and how the conditions of their formation may influence the emergence of the ingredients necessary for life.

The research was conducted by an international team of more than 30 astronomers as part of the COMPASS project, which studies complex organic molecules around protostars. The scientists examined disks around 11 young stars using the ALMA array located in the Atacama Desert in Chile.

Such disks consist of gas and dust that gradually come together to form planets and their moons. Their chemical composition determines which substances may end up on forming worlds. However, scientists still do not know nearly everything about how this chemistry changes from one young stellar system to another.

Why scientists are interested in methanol

Methanol (CH₃OH) is one of the most widespread complex organic molecules in interstellar space. It is also found in disks where planets are forming. Thanks to its high abundance, methanol is particularly useful for studying rare molecular variants in which ordinary hydrogen is replaced by deuterium, a heavier isotope of this element.

The ratio of ordinary hydrogen to deuterium depends on the physical conditions in the gas-and-dust disk. Therefore, such molecules can serve as distinctive chemical markers that help reconstruct the history of matter in a young planetary system.

During the COMPASS observations, deuterated methanol was detected in the disk around one of the 11 protostars studied — IRAS 4A2. It is located about a thousand light-years from Earth, in the Perseus molecular cloud.

This discovery makes it possible to study the chemical composition of the material from which planets may eventually form. But the presence of such a molecule by itself does not mean that conditions for life already exist in the system: it only helps us understand which chemical processes occur in the early stages of stellar system formation.

Microwave “masers” found around young low-mass stars

Another unexpected result was the detection of methanol maser emission in more than half of the protostars studied. It was especially common among the youngest objects.

A maser works on a principle similar to that of a laser, but it amplifies microwave radiation. In space, such sources arise naturally — for example, when methanol molecules collide and enter an excited state in shock waves.

Methanol masers had previously been found in disks around massive protostars, where intense physical processes take place. They have now been detected for the first time around younger, lower-mass stars, more similar in type to the future Sun.

According to COMPASS project leader Maria Drozdovskaya of the University of Bern, this shows that even in systems with low-mass stars, local extreme conditions can arise that were previously thought to be characteristic mainly of massive luminaries.

One possible reason is bursts of activity from a growing star that continues to accrete gas from the surrounding space. Such events can generate shock waves in the disk and intensify methanol maser emission. However, this mechanism still has to be studied in detail.

The researchers suggest that methanol masers may be a common outcome of the processes accompanying the formation of stars and planets, regardless of the protostar’s mass.

The chemical composition of future planetary systems varies

ALMA observations also revealed differences in the chemical composition of the disks around the 11 stars. In particular, the scientists noticed changes in the abundance of molecules containing oxygen and nitrogen.

This means that the chemical “starter kit” from which planetary systems form is not necessarily the same everywhere. It can be influenced by conditions inside the disk and by the evolutionary history of the young star.

Understanding these differences is important for studying the origin of complex molecules and the subsequent evolution of planets. However, it is still too early to draw conclusions about how often conditions favorable to the emergence of life arise in such systems.

Studying the chemistry of space will take several more years

The first results of the COMPASS project were published in seven papers in the October 2026 issue of the journal Astronomy & Astrophysics. The team continues to analyze data on various molecules detected with ALMA and is preparing follow-up observations with other instruments, including the James Webb Space Telescope.

According to Drozdovskaya, processing the full dataset collected will take several more years. Scientists will need to determine which chemical processes are universal for young stellar systems and which depend on specific formation conditions.

This work does not provide a direct answer to the question of the origin of life, but it helps investigate an earlier stage: which chemical substances exist even before planets appear, and how they may become part of the worlds that form around young stars.