In our solar system, the Sun is surrounded by eight planets and more than 210 planetary satellites (moons). Many asteroids and comets also orbit around the Sun.
The average distance between the planets is 149 600 000 kilometers, or about one Astronomical Unit. This measurement tells you how far away an object is from the Sun, which can be helpful for space travel.
The Earth is one of the eight planets in our solar system. It is the fifth-largest planet by diameter and the third-closest to the Sun. It is made of rocky materials and has an atmosphere that protects the surface from sunlight, heat and pollution.
Scientists think that the Earth formed around 4.5 billion years ago, and its moon is believed to have formed around the same time as well. The two merged to form the planet we know today, astronomers say.
As a result of the collision, Earth has an unusually complex structure. Its surface has layers that vary in temperature and density. Some parts are rocky, others are icy and others are made of minerals.
At the top of the atmosphere is a layer called the thermosphere. This is where the planet receives most of its radiation from the Sun. And it is also where the gases that make up our atmosphere are most concentrated.
From there, we move into the layer known as the exosphere. This is where most of our radiation and pollutants are emitted. This is also where our solar wind blows away the particles that fall into our atmosphere, making our climate warmer.
We also have an ocean that is made of liquid water. This is where most of our sea life thrives, including mammals, fish and plants. There are also strange and complex biospheres around hydrothermal vents on the ocean’s bottom, which astronomers think might be part of the planet’s deep interior.
Mars is the fourth planet from the Sun and is a large world in our solar system. It orbits the Sun in 687 Earth days. This is longer than the orbits of Mercury and Neptune, which orbit in a few days or weeks.
Mars was formed nearly 4.5 billion years ago from the same cloud of dust and gas that formed other planets. However, it differs from its neighbors in its composition and size. Its surface is composed of rock, sand, and minerals.
As a result, the planet has many different craters across its surface. These craters vary dramatically from region to region, depending on how old the surface is. Some craters are so large that they’re the size of a mountain. Others have a diameter of just a few miles.
The craters on the Martian surface may have been formed by impactors that hit underground water and ice. These water deposits can be as deep as 1,200 miles (2,000 km) below the surface.
There are also gullies, valleys and channels all over the Martian surface that seem to be caused by liquid water that once flowed across the planet’s surface. Scientists have discovered a number of these channels, and some can be 60 miles (100 km) wide and 1,200 miles (2,000 km) long.
The existence of water on Mars is an intriguing prospect. It would answer the question of whether we are alone in the universe, and it would also help scientists understand how microbial life developed on Earth and on other planets.
Jupiter is the largest and most gaseous planet in our solar system, but it also has a very rocky interior. This makes it a dangerous place to try and find life on its surface.
But that doesn’t mean that there aren’t some interesting things to see in its sky. For starters, there are several ring systems around the giant planet. And, as its magnetosphere swells out toward the Sun, it creates a magnetic tail that’s nearly 800 million kilometres (5.3 astronomical units; 500 million miles) long.
And, new findings from Juno show that there are cyclones in Jupiter’s atmosphere — not just the famous gas clouds we know and love — that churn thousands of kilometers below its surface. These storms have a different density at the top and bottom of the cloud, which means that they’re warmer on top but colder below.
What’s more, they seem to converge into polar cyclone groups at each of the planet’s poles. The northern group has nine cyclones, while the southern one is surrounded by five large storms and a single smaller one.
These findings are a big change from our previous model of the planet’s atmosphere. We thought that the signature bands we saw in the sky disappeared when they reached their poles, and that Jupiter’s atmospheric winds only reached up to the surface level. But new discoveries from Juno show that the cyclones are more complex than we thought and that their winds churn thousands of kilometers below the cloud tops.
Saturn is the sixth planet from the Sun and the second largest planet behind Jupiter. It is yellow in color due to ammonia crystals in its upper atmosphere. It also features a prominent ring system made of ice and rock particles that range in size and orbit speeds.
The rings of Saturn are one of the most beautiful parts of the Solar System. They extend from 6,630 to 120,700 km (4,120 to 75,000 mi) outward from the planet and average 20 meters (66 ft) thick. The rings are divided into several different sections, including the Cassini Division that separates the A and B rings and a gap measuring 2,920 miles (4,700 kilometers) in width called the Encke Division.
Astronomers on Earth have studied the refraction of starlight and radio waves from spacecraft passing through Saturn’s atmosphere. They have found that at depths corresponding to pressures of one-millionth to 1.3 bars, the temperature is roughly constant.
In deeper cloud layers, however, the temperature drops significantly as the pressure rises. At 4.7 bars, for example, the base of ammonium hydrosulfide clouds, the temperature is -150 degrees Celsius.
At 10.9 bars, the base of water ice clouds with aqueous ammonia droplets, the temperature is -140 degrees Celsius. Interestingly, these clouds are colored by chemical impurities like phosphorus, so the surface would be grey, brown, or yellow in a pure state.
On the north pole, a six-sided jet stream is formed from winds that swirl at about 200 miles per hour. This is an unusual feature on any planet, and it was first seen by Voyager I and is still observed by the Cassini spacecraft.
Uranus is the seventh planet in our solar system and the second-furthest from the Sun. Its distance varies according to where it is in its orbit, but scientists usually express this in astronomical units (AUs), which are equivalent to 93 million miles.
The planet is surrounded by a set of rings, but its inner system is relatively thin and dark. The rings are made of dark, fine dust particles, which resemble those of Saturn.
It also has a thick cloud layer that forms on top of a hydrogen-dominated atmosphere. The gaseous hydrogen absorbs red light, which causes Uranus to appear bluish-green.
In addition, the planet is incredibly rich in methane molecules. Methane is a powerful absorber of near-infrared light, and it makes up 2.3 percent of the atmosphere.
Another difference between Uranus and the other giant planets is that it has a 98-degree tilt on its axis. This causes a large variation in sunlight at the poles, which makes the seasons extreme.
The tilt also produces uneven warming across the two hemispheres. This means that the atmosphere is much less active on Uranus than on the other planets, resulting in fewer features such as storms and eddies.
Astronomers have used the Voyager spacecraft to detect a wide variety of radio emissions from Uranus, including maser-cyclotron and magnetohydrodynamic emission. These emitter types are not normally seen from the Earth, and they indicate a rich, complex magnetic field.
Neptune is one of the largest planets in the outer solar system. It is one of two ice giants, along with Uranus, and has a dense atmosphere composed of water, ice, methane, and helium. It is also known for its many moons, some of which are surprisingly small.
Neptune was formed around 4.5 billion years ago, and its orbital period is 164.8 Earth years. It is the second largest planet after Jupiter in terms of surface area, and the ninth largest in size overall.
The surface of Neptune is covered with clouds that have a blue color, which is due to the presence of methane gas in the planet’s atmosphere. This gas absorbs red light, giving Neptune its dark blue appearance.
Winds on Neptune are a mix of prograde and retrograde, depending on the direction of its spin. They range from 100 metres per second at the equator and poles to about 700 metres per second near latitude 70 deg S.
Neptune has at least five main rings and four prominent ring arcs, which are thought to be relatively young and short-lived. The rings, named Galle, Leverrier, Lassell, Arago, and Adams, start near the planet and move outward. They are not uniform, with four thick regions (clumps of dust) called arcs, which may be stabilized by the gravitational effects of Galatea, a moon that orbits inward from the ring.