How many solar systems are in the milky way

So I think that almost every star will have a solar system with a couple of planets, some rocky, some gas giants, plus stuff like comets, asteroids and so on. Source: Wikipedia Extrasolar planets. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. How many planetary systems exist in our galaxy? Ask Question. Asked 8 years, 1 month ago. Active 7 years, 8 months ago. Viewed 12k times. Improve this question. The light from the lighthouse is so bright that you would have a hard time spotting the flicker of a firefly.

In the same way, all stars are bigger and staggeringly bright compared to the planets orbiting them. So far, the planets outside our solar system have proven to be fascinating and diverse. The force of gravity there would be much stronger than here at home. You would weigh twice as much there as you do on Earth! Another planet, called Keplerb, turns out to orbit two stars. A sunset there would provide a view of two setting stars!

An illustration that shows what it might look like to stand on the surface of Keplerb. Meanwhile, the European Space Agency's Gaia mission measured the positions, distances, and motions of stars to get a more definitive estimate of how much light — and thus, heat — they bestow on their planets.

The study found that there could be million habitable planets in the Milky Way. Some are just 30 light years from the Sun, the data suggest. Scientists have confirmed the existence of more than 4, exoplanets, although 3, more suspected exoplanets are awaiting confirmation. Some of these planets have shown signs of potential habitability, but whether they do host life will be extremely difficult to determine.

The mass is estimated by looking at how the galaxy rotates, as well as its spectrum using spectroscopy. All galaxies are moving away from each other, and their light is shifted to the red end of the spectrum because this stretches out the light's wavelengths. This is called " redshift. Astronomers must also know what the inclination or orientation of the galaxy is before making an estimate, which is sometimes simply an "educated guess," Kornreich said.

A technique called "long-slit spectroscopy" is best for performing this type of work. Here, an elongated object such as a galaxy is viewed through an elongated slit, and the light is refracted using a device such as a prism. This breaks out the colors of the stars into the colors of the rainbow. Some of those colors will be missing, displaying the same "patterns" of missing portions as certain elements of the periodic table.

This lets astronomers figure out what elements are in the stars. Each type of star has a unique chemical fingerprint that would show up in telescopes. Any kind of telescope can do this sort of spectroscopy work. Kornreich often uses the inch telescope at the Palomar Observatory at the California Institute of Technology, but he added that almost any telescope of sufficient size would be adequate.

The ideal would be using a telescope in orbit because scattering occurs in Earth's atmosphere from light pollution and also from natural events — even something as simple as a sunset. The Hubble Space Telescope is one observatory known for this sort of work, Kornreich added. A successor observatory called the James Webb Space Telescope is expected to launch in The challenge, however, is that Hubble is a telescope in high demand — and the same is expected of Webb after its launch.