As you know, a lot has been discovered about space in a very short period of time. Scientists are always finding new information and proving themselves and other people wrong and right. We usually don't hear what people thought about space in the 20th century, which is why you probably do not know what people's knowledge of space was back then.
In the 19th and 20th century, people's space knowledge was very limited. They didn't know about things like black holes - an object in space which is where the gravity pulls so much no light can get out - which was first discovered by Karl Schwarzchild in 1916. If you are interested in finding out more about black holes, I highly recommend you use this link: nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html. In the early 20th century, people didn't really know about the moon's surface since no-one had been there and seen what it was like and they didn't really get a good idea by looking at satellites, which had been sent there by the Soviet Union and the USA.
Currently, our understanding of space is incredible. We know about all the planets in our solar system and we have even found out that one used to have water on and might still have water on. This planet is obviously Mars. I also remember watching a youtube video (youtube.com/watch?v=YojBpilJB00) talking about top 10 Earth-like planets. Humanity are thinking about going to some of these planets when Earth gets too hot and unhabitable. The number 1 on the list was Mars, showing that we will almost definitely live there in the very near future, probabably in our lifetime since it is very similar and close to Earth. Although this decision is not liked by many people, Pluto is now considered a dwarf planet whereas it used to be a planet and lots of American students were taught this acronym to remember the planets " My very excellent mother just served us nine pizzas ". Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
What do you think is the right knowledge?
Write a comment on what you think.