The Earth is isolated
The closest body to the Earth is its own natural satellite, the Moon, which is approximately 240,000 miles (about 386,243 Km) away. The nearest planet to Earth is Venus, which is approximately 26 million miles (about 41.8 million Km) away. The Sun is approximately 94 million miles (about 151.3 million Km) distant.The space between the planets and the sun is not only vast, but also empty, except for rare occurrences of extra-terrestrial debris (comets, meteorites) which add an insignificant amount of material to the Earth's surface. To all intents and purposes radiation from the sun is the only external input to the Earth.
What is the nearest planet to the Earth?