The closest planet to Earth changes over time depending on where each one stands in relation to the Sun in their orbital path.
Jupiter will come closer to Earth than it has in 59 years on Monday, making its presence visible for those with an effective telescope.
Venus
Venus, our closest planet neighbor, lies approximately 25.7 million miles away and 67 million from the Sun. Venus’ thick carbon dioxide atmosphere absorbs sunlight and keeps temperatures on Earth at an optimal level – creating an extreme greenhouse effect and producing what some have described as hell – clouds-covered world with burning, scorched streets filled with ash-covered earth-bound rivers that never end.
Venus boasts temperatures that could support life as we know it; however, scientists haven’t detected any evidence for it. Venus rotates slowly – taking 243 days per cycle to complete one rotation cycle – making it the slowest planet in our solar system; additionally its magnetic field strength is only 0.15 times stronger than our own Earth’s magnetic field strength.
Scientists aim to gain more insight into Venus’s inhospitable climate by sending a spacecraft called DAVINCI mission in 2020. A flying chemistry, imaging, and environment probe will descend from an altitude of around 50 miles into Venus’s thick atmosphere before collecting atmospheric measurements of noble gases and trace chemicals while surveying Venus’ rocky surfaces for signs of past water and its formation history.
Venus is no easy destination; without special protection, a spacecraft would quickly be crushed under air pressure, burned by intense heat waves, suffocated by carbon dioxide gases or dissolving into acid rain. Venus boasts valleys and mountains topped by thousands of volcanoes for easy exploration by spacecraft.
Mercury
Mercury orbits our Sun at an extremely fast rate, moving closer and further away at different times; but overall it remains the closest planet, even though Venus can occasionally get closer.
Astronomers at NASA, Los Alamos National Lab and the U.S. Army developed a model published Tuesday in Physics Today to calculate average distances among planets – they discovered that Mercury typically lies closest to all others in our Solar System.
Due to Mercury’s proximity to the Sun, its atmosphere consists of oxygen, sodium, hydrogen and helium – as it should. Mercury lacks massive craters like those visible on the Moon but has rugged terrain with cliffs up to one mile high – as seen from spacecraft observations by MESSENGER in 2012. One such study showed evidence of frozen pockets near both poles that may have cometary impact or have come from water vapour freezing within its core forming pockets of ice that have formed there over time.
Hubble Space Telescope has avoided looking directly at Mercury due to concerns for damage to its delicate optics, but ESA’s bepiColombo mission should have a tighter orbit that should allow closer observation of this planet.
Mars
Mars stands out in our night sky as the brightest planet, appearing as a resplendent red “star.” It blazes like an enormous fireball when it swings past Earth in the evening sky before reappearing in western skies just before dawn – it is only outshone by Venus which shines slightly brighter. Currently, Mars has reached its closest approach as part of its annual opposition, providing telescope owners an ideal time to observe it through backyard telescopes.
Mars will come so close this summer that it will appear larger and brighter than it has since its closest approach in 2003, when Earth was only 35 million miles from Mars; that was its closest approach in nearly 60,000 years!
Both planets move along an elliptical orbit, with distance between them constantly fluctuating. Mars Close Approach will occur simultaneously with our Sun closest to it this summer; hence its brightness in the sky.
Last opposition, astronomers used the Hubble Space Telescope to capture some of the clearest images ever taken of Mars and its two small moons, Phobos and Deimos. Now that Mars is closer than ever before, researchers should be able to witness its polar ice caps, water ice clouds, and dust storms with unprecedented clarity.
Jupiter
Jupiter is one of the brightest objects in our sky, and currently it stands out because it is at an angle close to Earth in its orbital path – although at times it may reach distances of 600 million miles from us!
Jupiter, our fifth planet from the Sun, is an enormous gas giant approximately 318 times as massive as Earth. Featuring thin rings and the Great Red Spot storm system, it spins once every 9.93 hours with the shortest day-length in our Solar System; also, its equator bulges while poles contract creating what’s known as an oblate spheroid shape.
NASA’s Juno mission will soon fly within 222 miles (358 kilometers) of Jupiter’s icy moon Europa on Thursday and may provide us with our best look yet at life beyond Earth if the spacecraft can capture high-resolution images revealing an ocean between layers of ice and water, challenging our perceptions about where life could exist in space. It could also deliver high resolution imagery of Jupiter that would show where its magnetic poles may exist as well as provide insights into where this life may exist in space. This discovery would challenge our perceptions about where we perceive life to exist compared to where our own world exists in Space!
Saturn
Saturn may not be suitable for growing plants, but it is still an aesthetically pleasing gas giant and one of the Solar System’s most distinctive planets, notable for its extensive ring system.
Saturn was formed shortly after Jupiter approximately 4.5 billion years ago during the early days of our Solar System, likely formed closer to the Sun before migrating outward over time and its gravity likely lifted asteroids and comets which later hit Earth, helping bring water here.
Saturn shares similarities with Jupiter in that it features a solid rocky core surrounded by hydrogen and helium, along with trace amounts of volatile elements like methane. Saturn also holds the least dense density amongst all Solar System planets with an approximate mass density of 0.6887 grams/cm3 (half as dense as water).
Saturn is most notable for its rings, composed of denser particles than those on Earth’s Moon. Separated by an expanse known as Cassini Division, these rings consist of seven main rings named alphabetically A through F plus inner B and C rings; their rotation takes 29 years and takes about one rotation every 10 hours and 39 minutes.
Astronomers have identified numerous moons of Saturn. Astronomers have discovered many fascinating moons of Saturn; Pan and Atlas appear like flying saucers; Iapetus has one bright side as bright as snow and another dark side like coal; Enceladus displays “ice volcanism,” where water and chemicals spew forth from an underground ocean. With suitable equipment, observers may observe these and other Saturnian moons like Hyperion at magnitude 15 and Phoebe at 16 – although viewing these requires 12″ telescopes under dark skies for viewing.
Uranus
Uranus, a gaseous, cyan-colored ice giant farthest away from Earth, boasts a complex ring system and 27 moons, spins on its side, experiences violent storms, has an appearance derived from methane gas emissions, is 20 times further from the Sun than Earth, and experiences cooler weather than Venus and Mars (both which experience high temperatures), making life unlikely there.
Scientists have studied Uranus through telescopes and satellites, providing images that reveal its rings system, clouds and smaller moons. Most recently images taken with the James Webb Space Telescope reveal smaller moons such as Bianca Cressida Desdemona Juliet Portia Rosalind Belinda Perdita.
Astronomers have investigated Jupiter’s surface, noting its unusual tilt of 98 degrees from its axis in relation to the Sun. This causes extreme seasons. Jupiter’s moons also possess unique features; Miranda has an odd mix of old and new surfaces as well as canyons up to 12 miles deep–larger than Grand Canyon! Furthermore, Miranda boasts relatively few large craters which scientists suspect were formed through recent low-impact collisions.