In fact, both the human body and the planet Earth have several connected systems that support life. The respiratory, digestive, reproductive, musculoskeletal, nervous, and immune systems all play important roles in human life. The planet's stability relies on the balance of its air, water, land, and life systems.

Venus is often called "Earth's twin" because they're similar in size and structure, but Venus has extreme surface heat and a dense, toxic atmosphere. If the Sun were as tall as a typical front door, Earth and Venus would each be about the size of a nickel.

Venus and Earth are very similar in size, mass, density, and element composition. The atmospheres, temperature, and surface of the planets are significantly different, making Venus a toxic and inhabitable environment. Venus is sometimes referred to as Earth's twin because of its similarities.

Venus is often referred to as our sister planet because of similarities in size, mass, density and volume. It is believed that both planets share a common origin forming at the same time out of a condensing nebulosity around 4.5 billion years ago. There the similarities end.

Venus, Earth, and Mars are sibling planets. They all have atmospheres, weathered surfaces, massive volcanoes, and chemically and thermally evolved interiors. Their atmospheres all possess clouds and circulate in response to the thermal forcing by the Sun, modulated by the effects of surface friction and planetary spin.

Venus, Mars and Earth, three out of the four inner or 'rocky' planets of the Solar System, have a lot in common – a solid surface you could walk on, a comparable surface composition, an atmosphere and a weather system.