There are many, many objects beyond Pluto, but where they came from and when they formed is a whole other question.
Rainbows are really cool because they’re a blend between art and science. It required a number of scientists to actually explain how they form, including Isaac Newton.
Counting the number of galaxies in the universe is tough, because we can’t see all of the galaxies in the universe. At a certain point, distant galaxies disappear from our field of view.
Water scarcity is essentially when there’s not enough water in the right place at the right time. Even in places that seem water-rich, it may not be clean enough for its intended purposes.
There’s actually gravity pretty much everywhere. But why do we feel gravity more here on the surface of the Earth instead of in space when astronauts appear weightless?