Mercury & Venus: The Closest Neighbors of Earth Mercury and Venus are the closest neighbors of Earth in the solar system. Despite their proximity, the two planets have distinct differences in terms of their characteristics and environments. Mercury, named after the Roman messenger god, is the smallest planet in the solar system. It has a heavily cratered surface, similar to the moon, with no signs of volcanic activity or plate tectonics. Its proximity to the sun makes it the hottest planet, with surface temperatures reaching up to 800°F (427°C) on its day side. However, its night side experiences extreme cold, dropping to as low as -290°F (-179°C). The planet’s year is only 88 Earth days long, but its slow rotation causes its day to be longer than its year, with one day on Mercury taking 59 Earth days. In contrast, Venus, named after the Roman goddess of love and beauty, is often called Earth’s twin due to its similar size and composition. However, its environment is vastly different. Venus has a thick atmosphere predominantly consisting of carbon dioxide, which creates a runaway greenhouse effect, trapping heat and raising the planet’s temperature to an average of 864°F (462°C). The atmospheric pressure is also 92 times that of Earth, making it a harsh environment for exploration. Venus has no moons and its rotation is unique, with one day longer than its year. Despite their differences, both Mercury and Venus have played important roles in our understanding of the solar syst（分析更多 生肖运势知识内容请关注 im星座网,WWw.imXinGzUo.cOm」em. NASA has sent several missions to explore Mercury, including the Messenger spacecraft and the upcoming BepiColombo mission, which is a joint venture between the European Space Agency and the Japan Aerospace Exploration Agency. The Soviet Union also successfully landed several probes on Venus in the 1970s and 80s. As our closest neighbors, Mercury and Venus continue to fascinate and intrigue scientists and space enthusiasts alike.