Get Solar System Webquest

A galaxy is a system of solar systems and other stars. Galaxies, like solar systems, are held together by gravity. In galaxies, the solar systems are separated by vast sections of mostly empty space. The galaxy that contains the Earth and its solar system is called the Milky Way.

The technology required to travel between galaxies is far beyond humanity's present capabilities, and currently only the subject of speculation, hypothesis, and science fiction. However, theoretically speaking, there is nothing to conclusively indicate that intergalactic travel is impossible.

The Milky Way contains at least one planet per star, resulting in 100 400 billion planets, according to a January 2013 study of the five-planet star system Kepler-32 with the Kepler space observatory.

Exoplanets are planets beyond our own solar system. Thousands have been discovered in the past two decades, mostly with NASA's Kepler Space Telescope. These worlds come in a huge variety of sizes and orbits.

Exoplanets are planets beyond our own solar system. Thousands have been discovered in the past two decades, mostly with NASA's Kepler Space Telescope. These worlds come in a huge variety of sizes and orbits.

The end of our solar system is the Oort cloud. It theoretically ends at about 2 light years from the Sun and that would be the end of the solar system. 2.5 light years (ly), nearly.

Voyager 1, Earth's most distant spacecraft, left the solar system and entered interstellar space in 2012. According to NASA, it is currently speeding away at 38,200 mph. For Voyager 1 to travel 39 light-years, it would take the spacecraft 685,000 years.

Humans have only managed to send one object beyond the reaches of our solar system: Voyager 1, which launched in 1977 and entered interstellar space in 2012. At the rate it's traveling, the robotic spacecraft won't encounter another star for at least 40,000 years, according to NASA.

So, to leave our Galaxy, we would have to travel about 500 light-years vertically, or about 25,000 light-years away from the galactic centre. We'd need to go much further to escape the 'halo' of diffuse gas, old stars and globular clusters that surrounds the Milky Way's stellar disk.

So far, astronomers have found more than 500 solar systems and are discovering new ones every year. Given how many they have found in our own neighborhood of the Milky Way galaxy, scientists estimate that there may be tens of billions of solar systems in our galaxy, perhaps even as many as 100 billion.