Venus is our closest solar system neighbor; yet how close exactly is she to Earth?
Science popularizers may have created the false impression that Venus is always Earth’s closest neighbor through their carelessness, misinterpretation or groupthink. To truly grasp reality we need to examine average distances between planets as they orbit each other over time.
Venus
Ask any average person which planet is closest to Earth and they will likely answer Venus; however, this distance depends on where each planet sits in their respective orbit.
On average, Venus lies about 67 million miles (108 million kilometers). But this distance can decrease to as little as 24 million miles (43.6 million kilometers) when Venus is at its perihelion or close to solar equinox.
As one of the brightest objects in our sky, Venus has long held human imagination captive. Once known as both morning and evening stars in ancient cultures’ mythologies and astrologies, and inspiring poetry by Homer, Shakespeare, and Virgil among many others – until telescopes made Venus known instead as a planet rather than star.
Venus is sometimes called Earth’s twin planet due to their similarities in size, density, gravity and composition. Unfortunately, however, Venus experiences significantly different conditions from those on Earth due to extreme greenhouse effects that make life near impossible there.
Venus boasts an atmospheric composition composed mainly of carbon dioxide and other gases, while layers of smog, haze, and vapor cover its surface. As a result, this dense atmosphere also makes Venus one of the hottest planets in our Solar System; temperatures on Venus range from about 900F (560C) at the poles to more than 1,300 F (672 C) near its equator.
Venus differs from Mercury by lacking a magnetosphere, meaning its metal core cannot generate its own magnetic field like Earth does. Instead, its thick atmosphere serves as a big brake on Venus’ rotation – slowing it by up to 80%! As a result, one day on Venus takes approximately 243 Earth days. Perhaps its unusually slow rotation could be related to Venus’ intensely hot atmosphere acting as an effective “thermo-phreatic brake.”
Venus has an intense, scorched surface dotted with wrinkled plains and volcanic cones, but the most captivating features can be found in its clouds that envelop it – made up of sulfuric and hydrogen oxides such as nitrosylsulfuric acid and phosphoric acid according to Britannica, these clouds may reach heights between 30-42-miles (48-668 km).
Mercury
The smallest planet in our solar system also happens to be one of our closest allies a lot of the time: Mercury orbits the Sun every 88 days, traveling an elliptical path which brings it as close to 29 million miles and 43 million miles respectively from it. Mercury is also the fastest moving object in space at nearly 112,000 mph (280,000 km/h).
Mercury can reach temperatures as high as 800 degrees Fahrenheit (430 degrees Celsius), reaching to 800 F on days when it has an atmosphere to retain heat. Conversely, night temperatures fall dramatically to as much as 290 below zero without an atmosphere retaining any of this warmth – prompting some scientists to suggest water ice may exist at both its north and south poles, sheltered from direct sunlight through deep craters that contain permanently shaded craters.
Atmospheres on Mars include oxygen and nitrogen with trace amounts of hydrogen, argon, xenon and krypton present. Its surface features numerous craters and impact basins formed when its core cooled and contracted over billions of years – these features crumpled the surface, producing long lobe-shaped scarps up to one mile high and crumpled scarps of thousands of miles in length.
Sumerians were among the earliest civilizations to recognize Mercury. They believed it to be home for Nabu, their god of writing.
Due to the danger of eye damage from direct sunlight, viewing Mercury requires special caution when undertaken during daylight hours when its maximum elongation appears nearly directly overhead at midday. At such times, telescopes can be utilized with minimal interference from Sunrays.
NASA’s MESSENGER probe discovered in 2012 evidence of an organic compound in Mercury’s core: Methylene dioxygen monomer. Although its formation remains unknown, scientists believe it might result from complex chemical reactions occurring near Mercury’s core-mantle boundary and could help further our understanding of how it formed and has changed through time; scientists hope to use this knowledge to improve future missions to Mercury.
Mars
“Which planet is closest to Earth?” is an age-old question for both laypeople and space researchers alike, particularly as we attempt to learn more about our solar system and where Earth stands within it. Additionally, researchers often consider sending manned missions out into space near Venus, Mars or Jupiter for scientific exploration purposes.
Technically speaking, Mars is the closest planet to Earth; it can approach as close as 25 million miles from our home planet depending on where both planets are in their orbits. Venus can get much closer when farthest away – sometimes up to 162 million miles! – when in what’s known as inferior conjunction.
Scientists have made great efforts since 1960 to explore Mars with probes sent from Earth. Many have reached its surface, including rovers and satellites which have covered up to 85% of Mars.
Mars resembles Earth in many respects, with clouds, winds, polar ice caps, volcanoes and canyons similar to Earth. Centuries of observations by terrestrial observers as well as spacecraft have revealed much about Mars; dark regions that might be oceans while lighter regions could possibly be continents, according to NASA reports.
Mars features a thin rocky crust 6 to 30 miles thick that’s composed of iron, magnesium, aluminum, calcium and potassium surrounded by an outer hot and rocky mantle that measures between 770-1,170 miles (2400-2100 km). Further inward lies its dense core of iron nickel sulfur that has the ability to create golden hues or greenish tints depending on which minerals are present on its surface.
Mars boasts two moons; Deimos orbits every 30 hours and measures only 10 miles across. Phobos is much larger and features deep grooves which may have resulted from either an impact or Mars’ gravity pulling it apart; projections estimate that within 50 million years Phobos will either crash into Mars or break apart into pieces.
Jupiter and Saturn, two outer planets that lie much further from Earth than Venus or Mars, are much further away than either. At its closest approach, Jupiter lies 367 million miles (590 million kilometers). Traveling at 50kmph would take approximately 306 days.
Jupiter
Jupiter, our fifth planet from the Sun, is an enormous gas giant that takes up more space than all the other planets combined in our solar system. It has 11 times Earth’s diameter and one-tenth that of Sun; and its storms and winds have long been observed by astronomers – something made even more dramatic by Juno data today.
Jupiter is composed of hydrogen and helium that has been compressed due to the immense pressure from its enormous size, turning into a giant ball of swirling gasses that generate a never-ending cycle of intense heat and light which produces powerful storms capable of spawning faster-than-ever cyclones than those seen here on Earth.
These conditions create an incredible combination of pressure and temperature that gives rise to an amazing series of jet streams visible around Jupiter’s colorful bands. Similar to ocean currents, but deeper within its layers than can be sensed with sensors on Juno. Scientists still don’t understand exactly how these structures form!
Jupiter boasts many fascinating features beyond its famous cyclones and jet streams, including belts and zones – white and reddish colors of clouds that stretch around its planet – separated by strong east-west winds of up to 335 mph (539 km/h). White clouds in zones are made from crystals of frozen ammonia while dark clouds found within belts contain various chemicals.
Jupiter may not be a solid planet, but it does possess several moons that orbit it. Galileo first discovered four major Galilean moons during his 16th-century observations; these helped establish the Copernican view of solar system which in turn inspired Newton’s laws of motion. Today there are 92 moons orbiting Jupiter; there may yet be more discovered in future.
Jupiter can be found an average distance from Earth of 367 million miles (590 million kilometres), though this could change depending on where Jupiter is in its orbit – for instance, being closer to its perihelion than to its aphelion will decrease this figure significantly.