Whenever asked which planet is closest to Earth, most will answer Venus due to the fact that at their closest points together Venus comes closer than Mars does.
However, the order may not be as apparent at first glance due to planetary orbits that are not circular but instead elliptical in shape.
Venus
Venus, often called our solar system’s “sister planet,” shares similar size and mass with Earth, making them very similar in terms of size and mass. Venus is an unforgiving world covered with volcanoes and toxic gases; an entire day lasts roughly 243 Earth days while being bathed in an atmosphere made up of 96% carbon dioxide with pressure more than 92 times greater than our own at sea level.
Venus boasts the hottest temperatures of any planet in our solar system, reaching an ardent 737 degrees Fahrenheit (261 Celsius). At such extreme temperatures, water molecules simply cannot exist on Venus’ surface and any that do form quickly evaporate when exposed to such intense heat. Yet Venus offers more than its temperature alone: its night has the longest duration among planets in our solar system.
But is Venus really our nearest planet? The answer to that question can be complicated. A popular method to measure distances between planets (and stars) is dividing their radii difference; however, this does not take into account that planets don’t follow perfect circular orbits; instead they resemble more like ellipses than circle shapes. When Venus passes directly in front of Earth every 584 days (when at its closest), Venus and Earth may come within approximately 67 million miles; at their farthest apart they could be 1.72 AU apart.
Because Venus can shift in position from time to time, it would not be accurate to claim that she is Earth’s closest planet. A more accurate way of measuring distance between planets has been developed: researchers calculate the average of distances from various points on each orbital path of each planet before averaging them together; this provides a more accurate representation of their relationship because each spends some time close together while other parts are further apart; using this approach, scientists found Mercury to be Earth’s nearest companion most of the time.
Mercury
Mercury is the smallest planet in our solar system and one of its closest companions, orbiting our Sun in just 88 days – only two-fifths the time required by Earth to revolve once. Due to being so close, Mercury experiences dramatic day-to-night temperature swings; during daylight it may reach temperatures hot enough to melt lead while night temperatures can dip as far down as minus 275. Astronomers speculate as to why such temperatures fluctuations exist on Mercury; one theory suggests it formed from something larger and left a large iron core behind.
Mercury’s compact orbit also means it is often the closest planet to Venus and Mars as well as Jupiter, Saturn, Uranus, and Neptune – although these outer planets tend to orbit further from Mercury over time; nonetheless they often come closer during short intervals during their orbits.
People attempting to estimate how close two planets are typically use average distances from the Sun as a proxy. But this doesn’t always give an accurate picture because planets vary their distance from it throughout their orbit, and to find out who the closest one at any given moment, one needs to consider how long each distance spent from the Sun for.
Scientists had long agreed that Venus was the closest planet to Earth because it spends most of its time closer to the Sun than further away, yet now a team of researchers has discovered that Mercury actually remains closer for longer periods than any other planet.
A recent research effort employed a sophisticated mathematical technique to calculate the proximity of planets within their orbits. The technique utilizes point circles, which measure distances among multiple points on each planet’s path rather than just between two points at once; additionally, this approach accounts for each planet’s speed of orbiting the sun. Results were published in Science Advances.
Mars
Mars, the fourth planet from the Sun, is well known for its reddish hue caused by an abundance of iron oxide. Yet it shares many similarities with Earth: both are terrestrial planets with thin atmospheres and various surface features such as impact craters, deserts, valleys, and polar ice caps. Like our Moon, Mars also features two small satellites named Phobos and Deimos that orbit their planet tidally locking into each other so only one face faces Earth; additionally there is evidence of ancient river valley networks, deltas formation as well as mineral and rock formations which could only have formed under liquid conditions.
Most people believe Venus to be our nearest planet, but that isn’t accurate. Scientists use an alternative calculation when identifying this closest planet: they subtract out average distance between planets from their orbital periods around the Sun; although this does give more accurate results.
Venus comes close to Earth from time to time, though most of the time is on the other side of the Sun from us – this makes it the nearest planet at times when in that position but not when in more distant orbital phases; Mercury, however, remains consistently closer.
To identify which planet was closest to Earth over time, scientists created a simulation of the solar system and observed its planets moving through their orbits for thousands of years. After computing their average distances from the Sun, they concluded that Mercury is currently closest to our home planet over time.
Mars and Mercury will come close together at just under 1deg separation in 2024, visible low above Sagittarius near dawn before dawn in the early morning sky. They may even rise slightly higher than Jupiter and Saturn did during their Great Conjunction event in 2020.
Jupiter
Jupiter is an immense gas planet that dwarfs all others in our solar system, boasting twice as much mass. Its clouds are colorful due to various trace gases such as ammonia ice, ammonium hydrosulfide crystals and water vapor. Due to Jupiter having no solid surface for life to exist on, Ganymede, Europa and Callisto may provide better conditions. NASA is already working on missions that aim to explore these fascinating worlds.
Jupiter, as the brightest planet in our solar system, boasts a dense atmosphere filled with more hydrogen than that found on Earth – together with helium and other trace gases – comprising most of Jupiter’s mass.
Jupiter’s gravitational pull causes its cloud bands to expand and burst into stripes which can be seen from Earth. Jupiter features the Great Red Spot – a long-lived storm producing jet streams which generate lightning across Earth – as well as numerous white spots which appear similar. Both features result from intense turbulence on Jupiter’s surface.
Jupiter orbits our Solar System faster than any of the other planets, taking less than 10 hours for one complete rotation on its axis compared to 24 for Earth. Furthermore, Jupiter has three faint rings surrounding it as well as a layer of water vapor giving its yellow hue an added flair.
Jupiter’s atmosphere can not only emit light but also produces three types of radio waves: decimetric, decametric and thermal radiation waves. While not the kind seen on television and radio programs, these radio waves resemble those that interfere with audio programs on car AM radios. These three varieties are known by their acronyms of decimetric, decametric and thermal radiation respectively.
Jupiter is home to four Galilean satellites known as Ganymede, Europa, Callisto and Io. Each Galilean satellite exhibits signs of tectonic activity on its surfaces: Ganymede’s craters are filled with silicate rock while Europa and Io have frozen outer layers which may hide an ocean beneath. Research on Io indicates it as being amongst the most volcanically active bodies within our Solar System.