> In astronomy, which of the following is the largest?Considering the Milky Way, Jupiter, our solar system, and the Oort cloud, theanswer is: the Milky Way. Photo courtesy: NASA, ESA.Our solar system includes our sun, planets, andobjects like moons and asteroids. Meanwhile, our galaxy, known as the Milky Way,includes hundreds of billions of solar systems. And now to really blow yourmind: the universe has billions of galaxies like ours.To put it all in perspective: if the sun was the size of a grain of sand, oursolar system would be about the size of your palm. The Milky Way, then, would be(get ready) about the size of North America. What's more: the Milky Way is justone of billions of galaxies in the universe. Feel small yet?In this sense, the major distinguishing factor between these cosmic groupings issize. But, if that wasn't enough, scientists believe that the universe is stillexpanding outward at its very furthest points. The big bang is the event said tohave given way to matter and life as we know it, and continues to be the sourceof the expansion of our universe. Did you know?The same way that the moon orbits around the Earth, and the Earth around thesun, solar systems orbit around inside their galaxies. However, a single triparound is no walk in the park: it takes the Earth's solar system roughly 200 to250 million years to complete its orbit.To see our galaxy in perspective, check out the video below.