The Planets of the Solar System

The sun, eight planets, satellites, asteroids, comets, gases and dust particles are the major components of our solar system. The sun is at the center of the system and all the objects revolve around it in their own orbits.

The solar system was formed 4.6 billion years ago by the gravitational collapse of a massive molecular cloud. The Earth is the third planet from the sun, and is the only known place in the universe where life has originated and evolved.

Earth’s Atmosphere

The atmosphere of the Earth is an incredibly complex mixture of gases, varying with time and space. The major components of nitrogen, oxygen, and argon remain constant, while trace elements like carbon dioxide and water vapor can vary considerably.

Dry air is composed of about 78% nitrogen and 21% oxygen, while carbon dioxide accounts for less than 1%. The rest is a mix of argon, methane, and various other gases.

These gases change with temperature, and there are five distinct layers within the atmosphere that are defined by changes in temperature and pressure with altitude. The boundaries between the layers are not fixed, and they can vary somewhat depending on weather conditions.

A layer of the atmosphere below the stratosphere is called the troposphere, and it extends from about 12 km (7.5 mi; 39,000 ft) above the surface to a point called the tropopause at an altitude of about 50 km (31 mi; 160,000 ft). It is in this layer that most of the weather takes place, with nearly all clouds formed here too.

The troposphere is also home to the ozone layer, which traps harmful ultraviolet radiation from the Sun and protects us from it. It also contains a layer called the planetary boundary layer, which can be as low as 100 metres (330 ft) during calm nights to as high as 3,000 m (9,800 ft) at midday in hot, dry climates.

Above the thermosphere is the mesosphere, which starts at 31 miles (50 km; 164,000 ft) above the Earth and ends at about 53 miles (80 km; 260,000 ft). It is in this region that the coldest part of the atmosphere occurs, reaching temperatures as low as minus 130 degrees Fahrenheit.

This mesosphere is much thicker than the troposphere and it reaches an altitude of about 80 to 550 kilometers (50 to 342 mi). It is here that particles are ionized by solar radiation, and this is where the phenomena known as Aurorae can be seen.

The exosphere, which starts at 500 km (310 mi; 25,000 ft) above the surface and extends up to 6,200 miles (10,000 km; 30,000 ft), is the outermost layer of the atmosphere. It is where atoms and molecules escape Earth’s gravitational pull into space, and where satellites orbit the planet. It is also where charged particles spiral around the Earth’s magnetic field lines, which make it behave like a giant magnet.

Earth’s Surface

A planet’s surface is the most prominent feature that distinguishes it from other bodies in its solar system. It contains most of the planet’s molten interior and is where life occurs on Earth.

The planet’s surface is shaped by its interaction with the sun and other objects in the solar system. This interaction has led to the formation of continents, oceans and a diverse array of landforms that provide habitats for animals and plants.

It also provides a solid base for Earth’s magnetic field to form. This magnetic field helps shield the planet’s surface from harmful solar radiation.

Most of the radiation from the Sun that reaches Earth is absorbed by the atmosphere, but some is reflected back to space. In total, about 70% of the incoming radiation from the Sun is absorbed by the atmosphere and Earth’s surface while around 30% is reflected back to space.

These absorbed and reflected energy are ultimately used to heat and cool the planet and its atmosphere. As a result, the balance between incoming and outgoing energy is crucial to driving our climate.

The incoming energy is made up of different types of radiation, including ultraviolet (UV), visible and infrared. UV radiation is a component of sunlight that can damage the eyes, skin and other body parts.

Infrared radiation is a component of sunlight that can affect the atmosphere, especially cloud cover. This is why the surface of Earth has a thick layer of clouds that block some infrared radiation from reaching its surface.

However, some infrared radiation can pass through clouds to reach the surface. This is why there are seasons on Earth and why the Northern and Southern hemispheres sometimes point toward or away from the sun depending on the time of year.

The solar system contains a variety of rocky and icy worlds. Some, such as Jupiter’s Galilean moon Europa, have cratered surfaces.

Craters are the most common type of landform in the solar system. They are formed by a variety of objects, such as meteors, comets and asteroids.

They can help scientists learn about the age of a planet, the nature and composition of its surface and how it was formed. They can also reveal how the planetary crust and mantle shifted and changed over time.

Earth’s Core

The core of a planet can be either solid or liquid, and sizes range from 20% of a planet’s diameter (the Moon) to 85% of its radius (Mercury).

The Earth’s core is the dense ball of iron-nickel inside which our planet rotates. It is also the source of our planet’s magnetic field, which shields Earth from charged particles ejected by the sun.

Scientists have long pondered the mysterious inner core of the planet. They have used seismic waves that travel through the core to study its composition and structure, which are influenced by pressure, temperature, and rock type. In the late 19th century, they discovered a “shadow zone” deep within the planet where some types of seismic waves—known as s-waves—were unable to transmit through Earth’s layers.

When s-waves disappeared in this region, it indicated that Earth’s inner core was liquid. Seismologists then discovered an increase in the speed of p-waves, another type of body wave, in that same core area.

Eventually, scientists discovered that the Earth’s core is solid. It is made of a hot, dense ball of mostly iron and nickel.

Because it is so dense, the core has been able to generate its own gravity, which causes a dynamo effect that pushes our planet’s crust and mantle upward. It also has the ability to change its magnetic field. This can result in geomagnetic pole reversals, which happen about every 200,000 to 300,000 years.

Now, scientists have found evidence that our planet’s inner core contains energized particles from the early sun. These particles, called solar noble gases, have hung out in the core and mantle for 4.5 billion years.

The researchers used a technique that combines data on earthquakes from around the world. They then analyzed a series of earthquakes that spawned seismic waves that traveled through the inner core. They found that 16 of these events spawned seismic waves that bounced back and forth multiple times.

They used this data to show that the inner core has been slowing down in recent years and has begun rotating slower than the rest of the planet. This has implications for the way we live on Earth, because it affects life on the surface.

Earth’s Moon

Earth is a planet in our solar system that revolves around the sun and has a natural satellite called the Moon. The Moon is a bit larger than a quarter of the size of Earth, making it one of the largest natural satellites in the solar system.

The Moon is a very interesting and mysterious object that orbits our solar system. Its appearance changes from day to day and from night to night, displaying various phases that are visible to the naked eye. It also has a complex history that has left us with several interesting things to learn about it.

Our Moon was formed 4.5 billion years ago from debris from Earth and an impacting body, probably Mars-sized. It is a rocky world that is surrounded by craters, caverns, and meteorite impacts.

It is one of the most interesting objects in our solar system and is a good example of how planets can form large moons. Other planets, like Jupiter and Saturn, have their own natural moons that are smaller in size than Earth’s moon.

A moon can be a very important part of a planet’s ecosystem. When a moon orbits closely to its host planet, it can affect the planet’s surface and atmosphere. This can also affect life on the planet.

The moon also has a huge influence on the planet’s rotational speed, or spin. When the Earth and Moon rotate around each other, a small drag forces the Earth’s rotation to slow down. The effect is known as “lunar braking.”

This has a dramatic impact on the length of a day on Earth. Without the Moon, a day on our planet would be much shorter, possibly only a few hours long.

In fact, if the Moon were not in our solar system, the Earth’s day and night would be much shorter and warmer than they are now. This could make it impossible for life to exist on our planet.

Another important effect of the moon on the Earth is its influence on ocean tides. The Moon’s gravitational pull tugs on the oceans and causes them to raise and lower.