Astronomes detected the emission of carbon monoxide and silicon monoxide from two strange interstellar objects. This composite image shows 1.2 microns light in cyan and 4.5 micron light in red. Credit: Alma (Eso/Naoj/Nrao), T. Shimonishi et al. (Niigata univ.)
In the century since Edwin Hubble discovered that the Milky Way is only one of the countless galaxies in the universe, our understanding of our domestic galaxy has grown with giant steps. But as recent research shows on a new type of cosmic objects, there is still a lot to learn.
The astronomers found two strange, dense and frozen objects by chance in 2021 during a survey on the album of our galaxy by the Japanese Akari satellite. A more careful look has shown that they are made of interstellar ice (containing both water ice and organic molecules) and dust. But a follow-up study recently published in The astrophysical diary I discovered that these dirty snowballs are not part of any known category. It is not clear what exactly they are and how they could have formed.
“They can represent a new class of interstellar objects that provide an environment in favor of the formation of Ices and organic molecules,” said Takashi Shimonishi, astronomer of the University of Niigata, Japan, who led the study, in a press release.
Organic molecules are the bricks of life. Until now, scientists have thought of forming mainly in dense molecular clouds (where the stars are born) or around the young stars, in protoplanetary records. But the new objects do not seem to adapt to any of these explanations. Finding organic molecules in an unexpected position challenges our understanding of how and where a complex chemistry can arise.
Identity: unknown
The frozen interstellar objects are generally surrounded by a haze of dust. But when Shimonishi and his team observed these goals using the large millimeter/submillimeter of Atacama (Alma) in Chile, they did not see that expected glow.
The radio emission of the objects instead showed the presence of more silicon monoxide than expected for molecular gas. This suggests dramatic invisible processes, because silicon monoxide is generally blocked in dust granules. Because so much of this is visible, the team thinks that a powerful source of energy can influence the gas around mysterious objects.
In narrowing the possible identities of the objects, scientists have excluded some explanations. Their characteristics initially seemed to correspond to those of the stars for children still bandaged in the gas and thick dust from which they formed – objects called young built -in star objects – or stars seen through dense nutritions of dust. But neither objects is found in a region that form a star; In addition, the two sources are not physically associated, despite appear close to heaven. (They are at separate distances of 30,000 and 40,000 light years away.) In addition, no cloud of dust is faced with either of them.
There are clouds of carbon monoxide surrounding each source, but move at different speeds, so scientists think they are not related. The bodies seem to go to drifting through the space completely alone, each of an unlikely ship for the seeds of life.
Seeds of life
Many scientists think that life on earth may have been sown by organic molecules from space, delivered through comets or meteorites. If these frozen objects provide an environment previously unknown for organic chemistry, they could offer clues to how the ingredients of life could be more widespread than we thought.
But anyway: what are they? Could they be relics of an unknown interstellar process? Family objects that behave strangely due to unknown circumstances? Future observations could define the true nature of the cosmic icebergs, perhaps by putting them in a new category.
For now, these two solitary walks remain a mystery.
