Space is filled with numerous vast galaxies with uncountable stars, planets, and moons. Many celestial bodies that have been observed and are seen to have craters on their surfaces. Both our sun and the moon have observable spots and dents. The sun’s blotchy appearance has a different story where the moon is pitted with ridges and craters.
The sun does not have craters on its surface. As a star, it is a hot ball of bubbling gases, so its surface is not like other astronomical bodies like the planets and asteroids. Sunspots are caused by disturbances in the sun’s magnetic field welling up to the photosphere, the sun’s visible surface. They appear dark because they are cooler than other parts of the sun’s surface.
Find out how craters are formed and how is the sun different from other astronomical bodies, below.
What Are The Craters On Surfaces Of Planets?
Craters are the most common landforms in the solar system. Craters can be found on all of the terrestrial planets. It consists of roughly circular, excavated holes caused by impact events. The circular shape is caused by material flying out in all directions as a result of the explosion upon impact, not by the impactor having a circular shape.
Types Of Craters
Craters observed on the surfaces of Earth, moon and other planets can be classified in following three types.
Impact craters are formed when a meteorite collides with the Earth (or another planet or moon). A large meteorite’s high-speed impact compresses or forces a large rock area downward. The rock is pulverised as a result of the pressure. The compressed rock, however, rebounds almost immediately after the strike.
Massive amounts of shattered material shoots upward, leaving a wide, circular crater where the rock once stood. The majority of the material falls around the newly formed crater’s rim. There are numerous craters on Earth’s moon. Millions of years ago, most formed when meteors, or bodies of solid matter from space, collided with the lunar surface.
Many impact craters can also be found on the Earth’s surface, though they can be difficult to spot. Meteor Crater, near Winslow, Arizona, is one of the most well-known craters on the planet. A 50-meter (164-foot), 150,000-ton meteorite slammed into the desert about 50,000 years ago, creating the crater instantly.
Most of the solar system’s rocky planets and moons have impact craters. The solar system’s “gas giants”, Jupiter, Saturn, Uranus, and Neptune, lack craters. Because these planets are almost entirely made of gases, there is no hard surface for a meteor to strike. Meteors that enter the atmosphere of a gas giant simply disintegrate.
Craters are frequently formed by volcanic activity. Some volcanic craters have steep sides and are deep. Others are shallow and wide.
A caldera is not the same as a crater. Craters are formed when a volcano’s rocks and other materials explode outward. Calderas are formed when the magma chamber of a volcano collapses inward. Craters are typically much smaller than calderas, and calderas are sometimes referred to as giant craters.
Summit craters are formed by volcanic material near or on the Earth’s surface. Volcanoes, such as Mount Fuji in Japan, may have only one summit crater. They could also have several. Mount Etna in Italy has four of them. Volcanic material is near the surface but not visible in some summit craters. Despite the fact that Mount Fuji is an active volcano with magma and gases beneath the summit crater, the risk of an eruption is extremely low.
A third type of crater is formed by an explosion. When materials or chemicals explode, the explosion displaces all the material around it. The debris often lands in a circular pattern around the site of the explosion, creating a crater.
Explosions can be natural or artificial. The explosion that creates a maar, for example, occurs naturally when water interacts with superhot magma from a volcano. Maars are a type of explosion crater as well as a volcanic crater.
The Composition Of The Sun
When we look at the makeup of the sun, we can understand why the sun’s surface cannot have craters. Imagine trying to crack a hot air balloon, it would probably not be possible. The sun is similar to hot air, it is a huge ball of hydrogen and helium held together by its own gravity.
The sun is divided into several regions. The core, radiative, and convection zones are interior regions. Moving outward, the visible surface or photosphere is followed by the chromosphere, the transition zone, and finally, the corona – the sun’s vast outer atmosphere.
Are Craters Often Formed On Surfaces Of Planets?
Cratering is a rare occurrence in the solar system today. Planets, moons, comets, and other celestial bodies have fairly stable orbits that do not interact with each other. Meteors do collide with planets—including Earth—every day. However, most of these meteors are the size of a speck of dust and do not cause any cratering. Most meteors burn up in the atmosphere as “shooting stars” before ever colliding with the surface of the Earth.
Which Planet Has The Most Craters?
Mercury has more craters than any other planet, which means that, as the smallest planet, it also has the highest crater density. Impact craters are prevalent on the surfaces of Mercury and the Earth’s Moon. Both bodies lack liquid water on their surfaces that would erode impact craters over time. They also lack an atmosphere that could disintegrate meteoroids on planets like the Earth and Venus before they impact the surface.
Craters are commonly observed in many astronomical bodies but are not present in the sun. The blotchy appearance of the sun is caused by a different phenomenon called sunspots. The sun is a burning ball of gases hence its surface does not have a solid crust where craters can form.