- Viewing Planets or stars at high altitude
We can not see planets or stars during the day time because of the scattering of the sunlight. But, in space, all planets and stars would be visible. Consider the situation that a rocket is going to space during the day time. At what altitude these stars or planets would become visible? On the contrary, consider an astronaut coming back from the ISS to the Earth during day time. Until what altitude he could see bright stars like Sirius or planet Venus?