Planets form life existence or more extensively in different "soups"

　　In the universe, no two "soups" are the same

　　-Planets are formed in organic soups with different ingredients

　　Today's viewpoint

　　A series of 20 papers published on the preprint platform arXiv on September 15 shows that astronomers have mapped the chemicals in the planet’s “nursery” in great detail.

　　The newly published atlas reveals the locations of dozens of molecules in five protoplanetary disks (the areas where planets form dust and gas around young stars).

　　Life exists or more extensive

　　The Harvard-Smithsonian Center for Astrophysics, astronomer Kailin Oberg, who led the project for the atlas, said that these planetary disks are full of organic molecules, some of which are related to the origin of life on Earth.

"This is really exciting. The chemicals in each disk will ultimately affect the type of planet formed and determine whether the planet can carry life."

　　The results of the study indicate that the basic chemical conditions that lead to the existence of life on Earth may exist more widely throughout the Milky Way.

Large organic molecules were found in the protoplanetary disk surrounding the newly formed star, and a similar disk once surrounded the young sun to form the planets that now make up our solar system.

　　The existence of these molecules is significant because they are "stepping stones" between simpler carbon-based molecules (such as carbon monoxide found in large quantities in space) and more complex molecules needed to create and sustain life.

　　Planets are formed in different "soups"

　　The new disk diagram shows that the chemical substances in the protoplanetary disks are not uniformly distributed in each disk.

Instead, each disk is filled with different planets to form a "soup" (molecular mixture or planetary composition).

The results show that the formation of planets occurs in different chemical environments, and when they are formed, each planet may be exposed to very different molecules depending on its position in the disk.

　　The lead author of one of the series of papers, Oberg, said: "Our atlas reveals the importance of where planets are formed in the disk. Many chemicals in the disk are organic, and the distribution of these organics in a particular disk varies greatly. . Two planets can form around the same star, and their organic content is very different, so life is likely to exist."

　　Another paper mapped the specific locations of 18 molecules (including hydrogen cyanide and other nitriles related to the origin of life) in five disks.

These images were taken by researchers using the Chilean Atacama Large Millimeter/Submillimeter Array Telescope (ALMA) in 2018 and 2019.

The collected data is as high as 100 terabytes, and the researchers spent two years analyzing it and breaking it down into a separate picture of each molecule.

　　The final illustration of each disk shows that even the chemical reactions that take place in a single disk are much more complicated than people think.

The researchers explained: "Each individual disk looks very different from the next, and has its own unique set of chemical substructures. The planets formed in these disks will experience very different chemical environments."

　　Importantly, the area of ​​the disk where these organic molecules are located is also where asteroids and comets form.

A process similar to the initiation of life on Earth may also occur in these disks—asteroids and comets bombardment to transfer large organic molecules to newly formed planets.

　　The researchers said: "The main results of this work show that the same ingredients needed to breed life on our planet are also present around other stars. The molecules needed to initiate life on planets may easily be in all planetary environments. discover."

　　In search of the future planetary newborn

　　The new research project not only provides opportunities for astronomers to study the chemical environment of the disc.

Oberg said: "Our team uses these atlases to show where some of the planets that are forming are located in the disk, which allows scientists to associate the observed chemical soup with the future composition of a particular planet."

　　Researchers are using the collected data and atlases to find new planets.

Astronomers are convinced that the planets were formed in the protoplanetary disk, but there is a problem: they cannot see them directly.

The dense gas and dust will last for about 3 million years, hiding young, developing planets.

　　The researchers said: "It's like looking at a fish underwater. We know they are there, but we can't see the fish in the depths. We have to look for subtle signs on the water, such as ripples and waves."

　　In the protoplanetary disk, gas and dust naturally revolve around the central star.

The speed of moving matter that astronomers can measure should be consistent across the disk.

But if a planet lurks below the surface, researchers believe that it will slightly disturb the gas moving around it, creating tiny deviations in speed, causing the spiraling gas to move in unexpected ways.

　　Using this strategy, the researchers analyzed the gas velocity around two of the five protoplanetary disks—the young stars HD 163296 and MWC 480.

Small fluctuations in the speed of certain parts of the disk reveal that a young Jupiter-like planet is embedded in each disk.

　　The researchers say that as the planets grow, they will eventually "form open gaps in the disk structure" so that people can see them, but this process will take thousands of years.

The researchers hope to confirm these findings one step ahead of the upcoming James Webb Space Telescope, and to confirm this result by studying more protoplanetary disks in the future.