An international team of astronomers has presented the first study of its kind. Within its framework, scientists tried to understand what exactly aliens could see if they studied our galaxy, the Milky Way, with instruments.
The study was published in the journal Nature Astronomy and is featured briefly by Space.com. Astronomers have tried to look at the Milky Way “through the eyes of aliens” in the same way that we now look at other galaxies. To do this, they used data from observations of our galaxy, obtained in recent years with the help of space telescopes and observatories.
In addition, the MaNGA survey was applied, which made it possible to analyze data from almost 10,000 galaxies. This revision made it easier for scientists to compare the Milky Way with them. For example, the MaNGA analysis helped to clearly define how the chemical composition of each galaxy varies on the way from its center to the outer regions. The scientists also used previously created computer models, including the TNG50 model, which makes it possible to follow the evolution of thousands of galaxies over 13.8 billion years.
The scientists then tried to piece together what extraterrestrial astronomers would see if they were to analyze the chemical composition of the Milky Way, specifically its metallicity. They compared the Milky Way to 321 galaxies in the MaNGA survey, which have about the same mass and the same number of stars as our galaxy. Analysis of the data has shown that our Milky Way is not a typical galaxy, which alien astronomers would probably have noticed. However, it is not unique either.
It turned out that about 1 percent of the galaxies in the MaNGA sample and 11 percent of the galaxies in the TNG50 simulation showed a structure of metals similar to the Milky Way. The discrepancy in the results turned out to be quite large. Astronomers attribute this to the uncertainty of the MaNGA data and the precision limitations of the TNG50 simulations. However, the comparative analysis helped establish that a chemical composition similar to that of the Milky Way is rare among other galaxies.
“The main takeaway is that our Milky Way is not a typical galaxy,” says study co-author Maria Bergemann, an astrophysicist at the Max Planck Institute for Astronomy. “In other words, the Milky Way probably could have evolved differently than other similar. objects… Interesting future research would be to measure more chemical elements. For example, oxygen, a key element for life on Earth, can be measured in other galaxies. Another potentially important element is carbon.”