The question of how many solar systems are in the Milky Way has intrigued astronomers for decades. Astronomers have been following many lines of evidence to understand the galaxy. But how many of these systems are actually planets? To answer this question, astronomers have used a wide variety of general techniques, including radio, optical, and infrared astronomy. Fortunately, this question has been answered for the most part.
We currently know of approximately 2×1011 stars in our galaxy, and we believe that at least some of them contain planets. The planets must be close enough to the star to make it habitable, or far enough from it that they are too distant to be habitable. Astronomers have detected 19 planets around 17 different stars, although this number is far lower than what the universe is capable of hosting planets.
The Milky Way contains billions of stars and is made up of several hundred billion solar systems. The number of solar systems in the Milky Way is approximately 10% of the total number of stars in the universe. Interestingly, however, this number drops drastically if there is life in the Milky Way. Considering that the Milky Way contains three hundred billion stars, the number of solar systems that are found within the galaxy is surprisingly small.
Some of the most well-known planetary systems have higher orbital eccentricity. These systems may have planets that have unstable orbital inclination, causing planetary bodies to collide. Some may have migrated and retained their natural satellites. Other planets may orbit the galaxy directly. Some planets may be ejected, which is possible if they had a large enough mass. If so, they would be known as rogue planets.
The distances to the stars and planets in the Milky Way are measured in parallax measurements, and scientists have used these measurements to map the galaxy. The closest confirmed system is Gliese 832 at 14.8 light years, and it is home to one Earth-mass planet. Another system that is known to have multiple planets is Gliese 876, located at 15.3 light years.
Another method to study planetary systems is to use Kepler telescopes. These telescopes detect planets that are edge-on to their parent stars. They also detect planets that transit away from the star. In this way, we can find more planets in the Milky Way. It is possible that there are hundreds of thousands of other solar systems in our galaxy. So how many solar systems are there? Let’s find out!
Open clusters are smaller and less massive than globular clusters, and they are mixed in with most of the system’s stars. The Sun is part of one of these systems. Open clusters can survive for a few hundred million years. However, a small fraction of open clusters can live for a billion years. The most popular theory is that the Milky Way contains a total of ten billion solar systems.