[ad_1]
Astronomers have searched the entire Milky Way to identify the safest places to live. It turns out we’re in a pretty good position.
But if the past year has made you feel ready to move to another planet, you might want to look towards the center of the galaxy, according to the new research.
The new discoveries were made by a group of Italian astronomers, who studied places where powerful cosmic explosions could have killed lives. These explosions, such as supernovas and gamma-ray bursts, spit out high-energy particles and radiation that can tear apart DNA and kill life. According to this logic, the most welcoming regions to life will be those without frequent explosions, astronomers have estimated.
“Powerful cosmic explosions are not negligible for the existence of life in our galaxy throughout its cosmic history,” said lead author of the new study, Riccardo Spinelli, astronomer at the University of Insubria. in Italy. “These events played a role in endangering life in much of the Milky Way.”
Related: 11 fascinating facts about our Milky Way galaxy
In addition to finding the deadliest hotspots, astronomers have also identified the safest places in the galaxy’s history, stretching back 11 billion years. The results show that we are currently at the limit of a wide range of hospital real estate. But in the youth of the Milky Way, the edges of the galaxy were a safer bet.
Galactic Goldilocks Zone
There are many factors that make a planet habitable. For example, the planets must be in a Goldilocks zone, where the heat and activity of their host star is not too much or too little – that’s right. But in addition to these local conditions, life also has to fight against harmful radiation from interstellar space.
Powerful cosmic events, such as supernovas and gamma ray bursts, scatter dangerous, high-energy particles at almost the speed of light. Not only can they kill all forms of life that we know of, but these particles can also strip entire planets of their atmosphere. After such an event, scientists believe that planets orbiting nearby star systems would be erased from life.
Related: The 9 Real Ways Earth Could End
“For planets very close to the stellar explosion, it is plausible that there is complete sterilization,” Spinelli told Live Science. “In these remote areas, mass extinction is more likely.”
The authors wrote in the study that a nearby gamma-ray burst may have played a leading role in the Ordovician mass extinction event around 450 million years ago – the second largest in Earththe story of. While there is no concrete evidence linking a specific gamma-ray burst to this extinction event, the authors believe it could be likely, given Earth’s position in the galaxy.
In search of security
Using models of star formation and evolution, astronomers calculated when specific regions of the galaxy would be inundated with killer radiation. At the start of the galaxy’s history, the inner galaxy about 33,000 light-years away was lit with intense star formation, making it inhospitable. At that time, the galaxy was frequently rocked by powerful cosmic explosions, but the outermost regions, which had fewer stars, were mostly untouched by these cataclysms.
Until about 6 billion years ago, most of the galaxy was regularly sterilized by massive explosions. As the galaxy aged, such explosions became less common. Today, the intervening regions, forming a ring 6,500 light years from the center of the galaxy about 26,000 light years from the center, are the safest areas for life. Closer to the center, supernovas and other events are still common, and in the periphery there are fewer terrestrial planets and more gamma-ray bursts.
Fortunately for us, our galactic neighborhood is becoming more and more convivial. In the long-term galactic future, there will be fewer extreme events nearby that could cause another mass extinction.
The new article’s conclusions seem reasonable at first glance, Steven Desch, an astrophysicist at Arizona State University, told Live Science.
“I am happy to see that they seem to put [the research] within a rigorous framework and have realistic expectations of what a gamma-ray burst would do, and take into account factors that people sometimes forget, “such as the fact that the energy and material released by gamma-ray bursts is not equal in all directions, said Desch, who was not involved in the new job. “I haven’t gone through their numbers in detail, but at first glance it’s reasonable.”
The new research, published in the March issue of the journal Astronomy and astrophysics, could one day help astronomers decide where to look for habitable exoplanets. But for now, the technology limits astronomers to only looking for nearby areas, Desch said.
Originally posted on Live Science.
[ad_2]
Source link