The space is mind bogglingly large. Our galaxy alone contains about 100 billion stars, and there could be trillions of galaxies in the universe. (And almost a trillion Certainly bigger than you think!) But do we know how many planets there are?
Astronomers have 5502 planets discovered around other stars (known as outer planets) in the Milky Way. Add the eight in our website Solar System (Not nine, sorry Pluto), and that gives us a total of 5,510 known planets, all located in our galaxy. Counting planets is a difficult task, however, astronomers are sure that there are plenty of other planets out there that we haven’t found yet.
“Although we only know about 5,000 planets at the moment, we can estimate that there is about one planet for every star.” Mark PoppenchalkThe astronomer at the American Museum of Natural History in New York City told Live Science. “Our galaxy contains 100 billion stars, and it likely has many planets around it. We can’t give an exact number.”
Poppenchalk described determining exoplanet totals as trying to figure out how many people live in your city without searching on the Internet. To get an exact number, you could try to meet people one by one and count them, but that’s not entirely practical. It is much easier to get an estimate using data such as the number of people living in one house, and the number of homes in a city.
Astronomers estimate that each star has approximately one planet based on observations. In order to find out what a typical stellar family looks like, astronomers look to our neighbors. Scientists have used it A few different techniques for searching for exoplanetsincluding transit method used by Kepler Space Telescope and the radial velocity method that led to The Nobel Prize-winning discovery of 51 Pegasi b. At both transits and radial velocities, astronomers look at the star rather than the planet, looking for small signs of a planet’s presence, as the amount of starlight decreases when the planet orbits in front of it or vibrates in the star’s position due to the star’s gravitational pull. planet in a row.
However, all the planets discovered so far are within the Milky Way; No one has definitely found an extragalactic planet (sometimes referred to as an exoplanet), simply because it is too far away to see. One technique, called microlensing, has revealed a handful of potential exoplanets.
“In our galaxy, microlensed planets are detected when their host stars gravitationally bend the light of distant stars behind them, and the planet’s mass adds a small extra flash in the lensing light.” Unibrand“Lensing has long been a staple in studies of distant galaxies, so it makes sense that we would be able to see faint planetary lensing signals in other galaxies as well, but we haven’t confirmed any,” the University of Kansas astronomer told Live Science.
To continue Poppenchalk’s city analogy, by looking beyond the Milky Way, we ask how many people live in all of Earth’s cities. “If our galaxy has about 100 billion planets, and there are a trillion other galaxies, and each one probably has the same number of planets, we can multiply that together to get 100 sextelion planets in the universe,” Poppenchalk said. (This is the 1 followed by 23 zeros.)
With so many planets, people often argue that there must be at least one other planet with life somewhere in the universe. However, astronomers still don’t know how rare life – and the conditions needed for its emergence – actually are. “We will have to wait at least a few decades for the next generation of large space telescopes focused on exoplanets (such as the Habitable Worlds Observatory) to start looking for life elsewhere in the galaxy,” Brand said.
