A solar system is a star and all of the objects that travel around it—planets, moons, asteroids, comets and meteoroids. Most stars host their own planets, so there are likely tens of billions of other solar systems in the Milky Way galaxy alone. Solar systems can also have more than one star. These are called binary star systems if there are two stars, or multi-star systems if there are three or more stars.
Page Updated: January 25, 2018
"How many planets are in the solar system? How did it form in the Milky Way galaxy? Learn facts about the solar system's genesis, plus its planets, moons, and asteroids."
Source: National Geographic (Youtube) Published: on Aug 30, 2017
"The vastness of space is almost too mind-boggling for the human brain to comprehend. In order to accurately illustrate our place in the universe, one group of friends decided to build the first scale model of the solar system in seven miles of empty desert."
Source: National Geographic (Youtube) Published: on Mar 2, 2017
Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova. When this dust cloud collapsed, it formed a solar nebula—a spinning, swirling disk of material.
At the center, gravity pulled more and more material in. Eventually the pressure in the core was so great that hydrogen atoms began to combine and form helium, releasing a tremendous amount of energy. With that, our Sun was born, and it eventually amassed more than 99 percent of the available matter.
Source: NASA Page Updated: January 22, 2018
'You'll never get your head around how big the universe is,' warns astronomer Pete Edwards of the University of Durham in this film about measuring astronomical distances. 'There are as many stars in the universe as there are grains of sand on the Earth.' So how far is a light year? And supposing our galaxy were the size of a grain of sand, how big would the universe be?
Source: The Guardian (Youtube) Published: Feb 12, 2013
Page Updated: September 26, 2018