Nation World News – The Solar System extends from the Sun, called Sol by the ancient Romans, and through the four inner planets, through the asteroid belt to the four gas giants and into the disk-shaped Kuiper Belt and the teardrop-shaped heliopause Goes far away. ,
Scientists estimate that the edge of the Solar System is about 9 billion miles (15 billion kilometers) away from the Sun. Beyond the heliopause is the huge circular Oort Cloud, which is believed to surround the Solar System.
The order of the planets in the Solar System, starting closest to the Sun and working outward, is as follows: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and then possibly Planet Nine.
The following is the order of the planets in the Solar System, quoted from AstroBackyard:
Mercury is the closest planet to the Sun and the smallest of the eight planets, which is only slightly larger than our Moon. The surface temperature of mercury varies widely, reaching 800°F (430°C) in the daytime and -290°F (-180°C) at night due to the lack of an atmosphere to retain heat. goes.
A day on Mercury is longer because the planet rotates slowly – it takes 59 Earth days to make one complete rotation. However, a year on Mercury passes much faster due to its proximity to the Sun. It only takes 88 Earth days, making it the fastest planet to orbit the Sun.
Two spacecraft have visited Mercury, including Mariner (1974/75) and Messenger (launched in 2004). Messenger orbited Mercury more than 4,000 times over four years, then crashed into the planet’s surface after running out of fuel. In 2016, scientists released Mercury’s first digital elevation model, which merged more than 10,000 images obtained by Messenger.
Diameter: 3,031 miles or 4,878 km
Distance from the Sun: 0.4 Astronomical Unit (AU)
Days: 59 Earth Days
Orbit: 88 Earth Days
Natural satellite: none
Venus is the second planet from the Sun and the second brightest natural body in Earth’s night sky after the Moon. It is similar to Earth in size and mass and is known as Earth’s sister or twin planets. Venus’s rotation period of 243 Earth days is slower than that of the other planets and is one of two planets that rotate in opposite directions (east to west).
Venus’s atmospheric conditions are an extreme example of the greenhouse effect. Its thick, toxic atmosphere traps heat, resulting in temperatures rising above 880 °F (471 °C), making Venus the hottest planet in the Solar System.
Due to these atmospheric conditions, detailed exploration of Venus is difficult. It was the first planet to be visited by a spacecraft (Mariner 2) and the first to land successfully (Venera 7), but the first detailed maps were not possible until the arrival of Magellan in 1991.
Diameter: 7,521 miles or 12,104 km
Distance from Sun: 0.7 AU
Day: 241 Earth Days
Orbit: 225 Earth Days
Natural satellite: none
Earth is the third planet from the Sun and the fifth largest. The Earth’s orbit around the Sun is of 365.25 days, rotating on an oblique axis that is responsible for the four seasons. Earth’s gravity interacts with the Moon, it is just a natural satellite, which helps stabilize the orientation of the Earth’s axis and slows its rotation which causes tides.
About 29% of the Earth’s surface is land (ie continents and islands), with the remaining 71% covered by water (ie oceans, lakes, rivers and freshwater). Earth’s outer crust consists of several tectonic plates with a solid inner core and a liquid outer core. Earth’s atmosphere is rich in nitrogen and oxygen and small amounts of some other gases.
Earth’s distance from the Sun, physical properties and geological history have allowed life to develop and exist on Earth. There are several million species of life on our planet, scientists believe, with many more species still to be discovered.
Diameter: 7.926 miles (12.760 km)
Distance from Sun: 1 AU
Days: 23 hours, 56 minutes
Orbit: 365.25 Earth Days
Natural Satellite: Moon
Mars is the fourth planet from the Sun known as the Red Planet because of the iron oxide (rust) in the soil. Mars is home to the highest known mountains and the largest canyon in both hemispheres and the polar ice cap that remains frozen throughout the year.
Because of its low atmospheric pressure, liquid water cannot be on its surface, only for a short time at its lowest altitude. Surface features and data from space missions have led scientists to believe that water could flow along the surface of Mars and still be in underground rock. Scientific evidence also suggests that Mars was once a hotter planet.
Mars is one of the most explored planets in the Solar System, including a mission to assess habitability and the possibility of life. The first spacecraft to visit Mars (Mariner 4) captured the first images of another planet from space.
Viking 1 was the first spacecraft to successfully land on the surface of Mars, and Sojourner, part of the Mars Pathfinder spacecraft, was the first robotic rover to operate on Mars. Additional astrobiology missions are planned with the rover Perseverance and Rosalind Franklin.
Diameter: 4.217 miles (6.787 km)
Distance from Sun: 1.5 AU
Days: 24 hours, 37 minutes
Orbit: 687 Earth Days
Natural satellites: Deimos and Phobos
Jupiter is the fifth planet from the Sun, the largest planet in our solar system and one of the brightest objects visible to the naked eye. It consists mostly of hydrogen and helium with traces of other gases. The outer atmosphere and internal heat have created cloud bands and the Great Red Spot – a giant storm that has lasted for more than 300 years. Jupiter also has three faint rings around the planet.
Jupiter also spins faster than any other planet, taking less than 10 hours to complete a rotation on its axis, compared to 24 hours for Earth. Jupiter’s four largest moons, known as Galilean satellites (Ganymede, Callisto, Io and Europa), show similarities to the terrestrial planets.
Several missions have flown from Jupiter, including Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Ulysses, Cassini and New Horizons.
The mission provided data on the Great Red Spot, uncovered volcanoes in Low, helped create the first detailed map of the Galilean satellites, discovered the rings of Jupiter, and provided close-up pictures of the planet and its largest moons. Future exploration will include a liquid ocean covered with ice on the moon of Europa.
Diameter: 86.881 miles (139.822 km)
Distance from Sun: 5.2 AU
Days: 9.8 Earth Hours
Orbit: 11.9 Earth years
Natural Satellite: 79
Saturn, also known as the ringed planet, is the sixth planet from the Sun and the second largest. Saturn is pale yellow in color due to ammonia crystals in its upper atmosphere and has a prominent ring system composed of ice and rock particles of various sizes and orbital velocities. The ring is about 20 meters (66 ft) thick and extends from 6,630 to 120,700 km (4,120 to 75,000 mi) from the equator.
Saturn has the second shortest day in the Solar System, taking only 10.7 hours to complete a full rotation. Like Earth, Saturn has a tilted orbital axis which means that Saturn also experiences seasons. Two of Saturn’s roughly 60 moons (Titan and Enceladus) show signs of geological activity.
The Cassini spacecraft is the largest interplanetary spacecraft ever built and has spent more than ten years orbiting Saturn, including crossing Venus, Earth and Jupiter. The mission ended in 2017 when fuel was low and it was deliberately burned in Saturn’s atmosphere to avoid the risk of contaminating Saturn’s moons.
During the end of its mission, Cassini traveled between the planet and its inner rings and brought it closer to Saturn than any other spacecraft.
Diameter: 74.900 miles (120.500 km)
Distance from Sun: 9.5 AU
Day: 10.5 Earth Hours
Orbit: 29.5 Earth years
Natural Satellite: 62
Uranus is the seventh planet from the Sun and, like Venus, rotates in the opposite direction to the other planets. Uranus is also the only planet that rotates on a sideways axis, meaning it spins on its side with the poles facing east and west.
Like the other giant planets, Uranus also has 13 light rings, although the outer rings are brighter in color and easier to see.
The oblique axis of Uranus. SPACE.com (Image credit: NASA and Erich Karkowska, U. Arizona)
In addition to water, ammonia and methane in the atmosphere of Uranus, there are gases like Jupiter and Saturn. The unique sideways tilt means that for about 84 Earth years, the Sun shines directly at each pole and the opposite half of the planet experiences a long, deep winter. It is the coldest atmosphere in the Solar System with a minimum temperature of 49 K (-224 °C; 371 °F).
Voyager 2 remains the only probe to Uranus to study the composition and structure of the atmosphere, moon and rings while making additional discoveries. Before moving on to Neptune, Voyager made its closest approach to the cloud top in 1986.
In 2009, an extension of the Cassini spacecraft mission to Uranus was evaluated, but declined to proceed with destroying it in Saturn’s atmosphere. Cassini will take 20 years to reach Uranus from Saturn.
Diameter: 31.763 miles (51.120 km)
Distance from Sun: 19.2 AU
day: 18 earth hours
Orbit: 84 Earth Years
Natural Satellite: 27
Neptune is the eighth and most distant planet in our solar system. It is the fourth largest planet and is composed of gas, ice, similar to Uranus, and has a series of moons and faint rings. Neptune is also the only planet whose existence was predicted using mathematics before viewing through a telescope. These predictions are largely based on changes in the orbit of Uranus.
Neptune has an active, visible weather pattern that is driven by the strongest and strongest winds of any other planet in the Solar System, reaching 1,500 mph (2,400 km/h). Neptune’s outer atmosphere is one of the coldest places in the Solar System.
Voyager 2 was the only spacecraft to visit Neptune with a flyby in 1989. The mission confirmed a faint ring system discovered years ago. Since the Voyager mission, additional observations from ground-based telescopes have continued.
Diameter: 30.775 miles (49.530 km)
Distance from the Sun: 30.1 AU
day: 19 earth hours
Orbit: 165 Earth Years
Natural Satellite: 14
Pluto is the ninth largest object orbiting the Sun and was known as the ninth planet until 2006 when the definition of a planet was changed, and it was reclassified as a dwarf planet.
Pluto is located in the Kuiper Belt and has an orbit that differs from the other planets in terms of its ellipse and inclination. The dwarf planet is made of ice and rock and is the largest trans-Neptunian object by volume and rotates (rotates from east to west) similar to Venus and Neptune. New Horizons remains the first and only spacecraft to fly by Pluto (2015). This historic journey took almost ten years and led to some interesting and unexpected discoveries.
Diameter: 2376,6 km (1.476 mi)
Distance from the Sun: 39 AU (may be between 30-49 AU)
Days: 153 Earth Hours
Orbit: 248 Earth Years
Natural satellites: 5 (Charon, Styx, Nix, Kerberos and Hydra)