A team of astronomers has, for the first time, created an image of “the snow line” that is now thought to be responsible for the creation of a solar system around a star.
The system they’ve been looking at is V883 Ori, 1,350 light years from Earth, which is in the first moments of its existence on the cosmic scale – only about half a million years old, and is at an early stage of development.
Using ALMA , with planet formation probably not yet started. The observations, taken in radio wavelengths by (the North American, European and East Asian co-funded Atacama Large millimetre/submillimetre Array in Chile), the researchers were able to identify where in the system it gets cool enough for water to freeze out into a solid, influencing the formation and composition of the first bodies within the solar system.
Liquid water can’t exist in space, so ice that gets close enough to a star or protostar (a contracting mass of gas about to form a star) will heat up enough to go from its solid form straight to gas.
The water snow line is the distance from the protostar where this transition takes place. Snow can also form is space from other substances like carbon dioxide and carbon monoxide which each have their own snow lines at varying distances from the protostar.
It’s believed that once snow and ice has formed in space it can form the core of gas giant planets (like Jupiter) or comets like 67P/CG which the Philae lander touched down on after descended from Rosetta spacecraft in 2014.
In our solar system and possibly most others the gas giant planets formed outside our own snow line and rocky planets inside. But scientiosts say the snowline can also move vast distances further away or closer to a star through time depending on the materials available and the intensity of the star.
Snow lines in space have apparently been hard to spot previously as they’re often very close to their stars.
“Young stars are often surrounded by dense, rotating disks of gas and dust, known as protoplanetary disks, from which planets are born. Snow lines are the regions in those disks where the temperature reaches the sublimation point for most of the volatile molecules. In the inner disk regions, inside water snow lines, water is vaporized, while outside these lines, in the outer disk, water is found frozen in the form of snow. These lines are so important that they define the basic architecture of planetary systems like our own,” a statement from ALMA reads.
