2. Write answers to a question? Ancient people knew how many planets? Mercury what was the planet? Mercury has an atmosphere? Mercury is hot inside?

Ancient people knew about five planets: Mercury, Venus, Mars, Jupiter, and Saturn. These planets are visible to the naked eye and were known to ancient civilizations such as the Greeks, Romans, and Chinese.

Mercury is the innermost planet in the solar system and is named after the Roman god of commerce, travel, and thieves. It is the smallest planet in the solar system and has a rocky surface with numerous impact craters.

Mercury has a very thin atmosphere that consists mostly of oxygen, sodium, and hydrogen. The atmosphere is so thin that it is not capable of protecting the planet's surface from the intense solar radiation and meteor impacts.

Mercury is hot inside due to the effects of the sun's radiation on its surface. The surface temperature can reach up to 840 degrees Fahrenheit (450 degrees Celsius) during the day, while the temperature can drop to -290 degrees Fahrenheit (-180 degrees Celsius) at night. Despite this extreme temperature variation, there is no water on the surface of Mercury because the planet's atmosphere is too thin to retain any water vapor.