The Solar System consists of the Sun and eight planets, plus their moons, along with asteroids and other minor planets. It formed 4.6 billion years ago from the gravitational collapse of a giant molecular cloud.
The process of planetary formation is fairly straightforward. It is likely that the gas and dust in the solar nebula coalesced into rocky or metal-rich chunks relatively quickly.
Earth is the third planet from the Sun and the only world in the solar system known to harbor life. It has a large ocean of surface water and an atmosphere rich in nitrogen and oxygen. It also has a shifting crustal section floating on a hot mantle below, described by the theory of plate tectonics.
The Solar System is an assemblage of eight (formerly nine) major planets, their natural satellites, asteroids and comets that orbit the Sun in elliptical orbits. The asteroid belt, the Kuiper belt and other parts of the Solar System contain objects composed of rock, metal and ice.
Scientists use a variety of methods to understand the formation and evolution of planets, moons and other bodies in the Solar System. Understanding how these objects form helps astronomers find and explore more inhabited worlds in the universe.
Using astronomy, space exploration and other techniques to study the planets, stars, and other objects in the Solar System provides observable patterns that can be used to predict changes and events like eclipses, lunar phases, seasons and weather. This enables scientists to make informed decisions about future explorations.
The earth is round, not flat, and it rotates on its axis at about 1,532 feet per second (about 467 meters per second). This is supported by geodesy, the science of measuring Earth’s shape, gravity and rotation with satellites and other instruments.
Jupiter is a huge gas giant and the largest planet in our solar system. It is made of 90% hydrogen and 10% helium – similar to the Sun’s composition.
It has been shaped by gravity pulling swirling gas and dust over a period of about 4.5 billion years. It has a sprinkling of moons, most notably Ganymede.
One of the most fascinating things about Jupiter is its raging storms and powerful winds, including its Great Red Spot. NASA’s Juno spacecraft has been circling the planet since 2016 and has provided incredibly detailed images of violent tempests carried along by its rapid rotation.
The spacecraft’s observations have also provided a number of clues about Jupiter’s weather overall, like wind patterns, atmospheric waves and cyclones, as well as its gases and heat.
These findings will help scientists piece together more clues about the formation and inner life of Jupiter.
NASA released a pair of new Jupiter images that showcase the glowing auroras, hazes and clouds that swirl around Jupiter’s poles in different infrared wavelengths. The images were taken with Hubble’s Wide Field Camera 3 and Gemini North’s Near-InfraRed Imager.
Saturn is the second largest planet in the solar system, behind Jupiter. It has a large number of moons, including Titan, the largest and most notable.
Most of Saturn’s atmosphere is made up of a mix of hydrogen and helium, with traces of methane and ammonia. The upper reaches of its atmosphere are scoured by violent winds that move almost five times faster than Earth’s hurricanes.
Its interior is similar to that of Jupiter, with a rocky core and layers of liquid metals and liquid hydrogen. It also contains traces of ices.
The planet’s rings are a network of orbiting chunks of ice that extend out from its atmosphere. The outer ones are called the A, B, C and D rings.
In recent years, Cassini has detected a mysterious color change in the northern hemisphere of Saturn. The northern part of the planet now appears a bright blue.
This is the first time the planet’s northern hemisphere has ever changed color, scientists say. Scientists don’t know what caused it, but they suspect it may be related to colder temperatures.
The spacecraft also discovered that Saturn’s magnetic field is changing, which could be linked to changes in the planet’s core. The changes in the magnetic field may be causing a slowing of the planet’s rotation rate. These are just a few of the mysteries surrounding Saturn that scientists are attempting to solve.
Uranus is a blue-green gas giant that orbits the Sun with an axial tilt of 98 degrees. It takes 84 Earth days to complete one orbit and is so close to the Sun that its north and south poles almost lie sideways on its axis. This extreme axial tilt may have arisen from the collision of planets similar in size to those present in our solar system.
Until 1986, when Voyager 2 flew by Uranus, the planet had remained largely invisible to spacecraft. Despite this, the mission took thousands of pictures of Uranus’s moons and rings.
The smallest and innermost of the five main Uranus satellites, Miranda, has a complex geologic past. Its surface features cosmis-debris pitted areas, halo-effect craters, and numerous scarps and faults that create banding on the surface. Compressional tectonics were also thought to have contributed to the moon’s complex surface.
Like the other gas giants, Uranus has a thick layer of methane in its atmosphere that absorbs red wavelengths of sunlight. This gives the planet its unique blue color. However, unlike its kin, Uranus does not radiate more heat than it receives. This suggests that the planet’s interior is cold and lacks a heat source.
Scientists have learned a lot about the atmospheric structure of Uranus through ground-based telescopes and advanced imaging technologies used by the Hubble Space Telescope. Through these techniques, they have found that the southern hemisphere of Uranus has a bright polar cap and a dark equatorial band. These bands can be seen as latitudinal stripes on the planet’s visible surface, and they can be accompanied by winds that can blow in excess of 576 km/hr.
Neptune, the Roman god of the sea and a son of Saturn, is the second-largest planet in our solar system. This gas giant is the only planet in the Solar System that was discovered by calculation rather than observation. In 1846, astronomers Urbain Le Verrier and John Couch Adams independently calculated the position of Neptune by studying gravity-induced disturbances in the orbit of Uranus.
Neptune’s atmosphere is dominated by hydrogen and helium. The temperature varies with altitude and pressure, reaching a minimum of 50 kelvins (K; -370 degF, -223 degC) at the 0.1-bar level. The higher levels have a lower temperature and are largely composed of methane, but some are thought to be ice-rich.
Winds on Neptune range from 100 metres per second (360 km [220 miles] per hour) at the planet’s equator to 700 metres per second (2,520 km [1,570 miles] per hour) at the south pole. They are primarily driven by the planet’s rotation.
The James Webb Space Telescope released fresh space images of Neptune and its rings Wednesday, showing the outermost planet in its best light for decades. The photos show Neptune’s thin, bright rings, faint dust bands and seven of its 14 known moons.
The Webb telescope’s infrared capabilities enable it to see through the haze that covers Neptune and other stars and galaxies. The new images also reveal a mysterious band of brightness circling the planet’s equator, suggesting that atmospheric circulation is powerful enough to power Neptune’s winds and storms.
Pluto is a dwarf planet that’s smaller than our Moon, and denser than any other planet in the solar system. Its orbit overlaps with Neptune, which led to its demotion as a planet in 2006.
Scientists have been learning about Pluto since 1927. But it was only in 1988 that a chance alignment allowed astronomers to see the dwarf planet for the first time.
After a few months of studying it, astronomers were able to create a picture that showed us a lot about Pluto, including what makes it special and where it might be hiding.
One of the most notable features is Sputnik Planitia, an icy basin that’s churning with huge glaciers, reminiscent of Earth’s oceans. What’s more, it has a network of strange polygonal shapes that resemble cells under the microscope.
These strange polygons are a product of internal heat that’s trying to escape underneath the frozen plain. Warm ice rises into the center of these polygons while cold ice sinks along their margins.
Researchers believe this activity is the reason that Pluto’s surface ices are so diverse, with some areas incredibly bright and others dark as charcoal. It also suggests that Pluto’s surface is changing over time.
Another intriguing feature is a pair of bladed ridges on the far side of Pluto that seem to have been formed when earthquakes struck in a distant past, just like those found on Mars and Mercury. But on the far side, these bladed ridges stretch across an area that’s 3.5 times larger than on Pluto’s near side.
The solar system consists of the Sun, nine planets and their moons, as well as many other non-stellar objects. It formed 4.6 billion years ago from the collapse of a giant molecular cloud.
The four planets closest to the Sun – Mercury, Venus, Earth and Mars – are terrestrial, meaning their densities are similar to those of our own. The rest – Jupiter, Saturn, Uranus and Neptune – are gas giants.
The biggest planet in the solar system, Jupiter is a gas giant with a dense atmosphere. It has a ring and four large moons – Io, Europa, Ganymede and Callisto.
The fast rotation of the gas giant, which rotates once on its axis every 10 hours, creates jet streams that separate its clouds into dark belts and bright zones across long stretches.
Scientists think that these bands of colors are plumes of sulfur and phosphorus-containing gases rising from the planet’s warmer interior, extending upward from the clouds.
Researchers hope that these images will help them to better understand how gases and heat move throughout the giant planet.
The new space images come courtesy of NASA’s James Webb Space Telescope, which trained its lens on our planet closer to home for the first time. The images reveal shining auroras, swirling clouds and raging storms on Jupiter, allowing scientists to peer into its complex interior.
Saturn is a gas giant planet that sits in the outer part of our solar system. It has a thick atmosphere with high pressures and icy surface features.
Its ring system is the largest and most complex in our solar system. Its rings are made up of three main bands, dubbed the A, B and C-rings.
The inner ring, known as the F-ring, is knotted or braided, a strange feature that wasn’t detected until the Voyager spacecraft explored Saturn in 1980 and 1981.
As with Jupiter, Saturn’s atmosphere is dominated by a strong east-west flow that creates light-coloured cloud bands. These bands vary over time and look like a complex of small-scale red, brown and white spots, bands, eddies and vortices.
A rare storm is seen near the equator in this image taken by Hubble. It’s a white arrowhead-shaped feature with an east-west extent of equal to the planet’s diameter.
Uranus is one of the most interesting and mysterious planets in the solar system. Its axis is tilted by 60 degrees with respect to the plane of its rotation and it does not have a magnetic field centered on its center of mass, as do most other planets in our solar system.
This unusual position is believed to be the result of a collision with a smaller object early in the solar system’s history. Its lopsided magnetic field also causes its day-night cycle to be reversed.
The atmosphere of Uranus is made up mainly of hydrogen and helium. Astronomers have calculated that the ratio of helium to hydrogen is about 15 percent, which matches the value of helium in the Sun.
Uranus is surrounded by a dark ring system that extends from its south pole to its north pole and consists of several small satellites. Most of these were discovered by Voyager 2, though astronomers have found another 12 outer irregular moons that were not imaged by Voyager 2.
Pluto is one of the largest and most remote objects in our solar system. It’s two-thirds the size of Earth’s Moon and 1200 times farther away, making it difficult to view from Earth.
It also takes up a significant part of our solar system’s Kuiper Belt, the region of debris and frozen remnants of planetary systems that may have once formed in the outer reaches of our solar system. But unlike the other Kuiper Belt planets, Pluto doesn’t have a companion planet.
It does, however, have several moons, most notably Charon, the largest, whose diameter is just over half that of Pluto. The Pluto-Charon system is sometimes considered a binary system, because the barycenter of their orbits does not lie within either body.