The Sun is a star made of hot plasma that glows and erupts solar flares, with a dense core generating energy through particle reactions. The Moon has no light or atmosphere of its own, rotating as it revolves around Earth in 28 days, always showing the same face. The changing phases of the Moon are caused by the varying illumination of its surface from Earth's perspective over the lunar cycle. In 1959, the Soviet Luna 2 was the first spacecraft to reach the Moon, followed by the 1969 Apollo 11 mission where Neil Armstrong became the first person to walk on the lunar surface.