Universe / 6 min read / 18 May 2021
Before exploring our colossal universe, let’s start from our home.
Moon, the closest celestial body to our planet. It is our planet’s only natural satellite if we don’t consider the many other temporary satellites. There are many asteroids that come into Earth’s orbit and become temporary satellite but they detach after some time and fly off in interplanetary space. The moon is at a distance of about 384,400 km, which at first may sound like a lot but is even more. To get a better idea of this distance, we should know that all the other planets in our solar system including Pluto can fit between our moon and Earth. It is undermined how far away the moon is.
Speaking of being furthest, Voyager I is the furthest object that humankind has sent out of our planet. It travels at a jaw-dropping speed of about 17 km/s or 10.5 miles per second. That’s about the height of two Mount Everests travelled in 1 second. The probe has flown by Jupiter and also Saturn. It is about 22.8 billion km away from Earth, flying further and further through interplanetary space. Even at these kinds of speeds, Voyager will leave our solar system after about 28000 years. Our solar system has a diameter of about 287.46 billion km from one end to another. Pluto and Arrokoth few of the dwarf planets are present in the Kuiper Belt — a doughnut-shaped region of icy bodies beyond the orbit of Neptune. There may be millions of these icy objects, which are collectively referred to as Kuiper Belt objects (KBOs) or trans-Neptunian objects (TNOs), in this distant region of our solar system. If we Venture further, we reach the Oort Cloud, which is the most distant region of our solar system. The nearest objects in the Oort Cloud are thought to be many times farther from the Sun than the outer reaches of the Kuiper Belt. After we leave the solar system, we would still have to cross the Oort cloud. The outer limit of the Oort cloud defines the cosmographic boundary of the Solar system.
100 to 400 billion of these star systems make up our galaxy, which is called the Milky Way. It is a spiral galaxy of about 100,000 light-years. Our galaxy has a spiral pattern with 4 enormous arms radiating outwards, and we live in one of them, about two-thirds of the way outward from the centre. About 100 billion stars in the Milky Way orbit a supermassive black hole at the galaxy’s centre, which is estimated to be four million times as enormous as our Sun. The supermassive black hole does not alarm us as it is at a safe distance from Earth, at about 28,000 light-years away. We call our galaxy the Milky Way because to ancient observers our galaxy looked like a milky belt stretching across the dark sky.
Well, we have not finished telling you about the Universe yet. We will release part 2 soon!!!! Delving deeper into the unknowns of the Universe.