Surface Feature of the Planets in Our Solar System

Surface Features

Introduction:

Our planet Earth is a part of the solar system, which has 8 planets in total revolving around a star named the Sun. All the planets of the solar system have different compositions and are made up of different components. In this session, we are going to look at the surface features of the planets one by one.

Explanation:

Every planet has different features of their surface such as craters, volcanoes, color, mountains, tectonic plates, etc. Some planets do not even have a surface.

Surface Features of Mercury:

Mercury is the closest planet to the Sun and it moves around the Sun in a highly elliptical orbit. As it is the closest planet to the Sun, it is the fastest-moving planet. There has been only one spacecraft named the Mariner, which has visited Mercury and took a picture in 1975. The surface of the Mercury has numerous craters and plain regions, crisscrossed with compression folds and escarpments.

After it was formed, it was hit heavily by large asteroids and comets, which caused its extremely cratered surface. This along with the periods of strong volcanic activity, resulted in the smooth plains, resulting in a very hilly surface. The maximum temperature that Mercury can reach is 427^o C, and it is a planet of extreme temperature variations, i.e., a minimum of -183^o C near the poles.

There may be deposits of minerals and ice within the craters near the poles. The deepest craters are found near the poles. The polar regions are the most likely to hold ice because they always stay shadowed never rising above – 173^o C.

Surface Features of Venus:

Venus is similar to the Earth in size, mass composition and distance from the Sun. However, it has no oceans and is fully covered with thick clouds. It has an atmosphere mostly comprised of CO₂, a greenhouse gas, that acts as a blanket to keep the heat in. It absorbs the infrared radiation emitted from the surface. That’s why its temperature is the highest among others, i.e., 471 ⁰C.

Everything that we know about Venus’s surface is from the radar because the atmospheric pressure is too high for a probe to survive longer than an hour. It has a relatively flat and smooth surface because it has an atmosphere that burns up most meteors before hitting its surface. Its surface is about 13 km between the lowest and the highest point. Most of its surface falls into one of the 3 categories: highlands, deposition plains, and lowlands.

There are some mountain ranges as well. It also has about 150 large shield volcanoes (many of which are called pancake domes, as they are wide and flat) and hundreds of thousands of small volcanoes as well.

Surface Features of Earth:

The Earth is the only planet that is believed to have life on it. The Earth looks blue due to the water content (70%) and hence it is called a blue planet. The lithosphere comprises both the crust and part of the mantle – specifically, the part that is rigid but has elasticity and becomes brittle over thousands of years.

The lithosphere is divided into tectonic plates, pieces that are about 100 km thick and move on top of the flowing asthenosphere, which lies underneath the lithosphere. Volcanoes and earthquakes often occur along boundaries between plates.

Plate boundary movement is also responsible for creating oceanic trenches and mountains. Some plates have hot spots – areas of volcanic activity under the mantle within the plate, where volcanoes often form.

Surface Features of Mars:

It is so thin that the average atmospheric pressure is less than 1% of that of the Earth. Its surface temperatures vary greatly from -133 ⁰C to 27 ⁰C. Mars has incredibly different northern and southern hemispheres. Most of the northern hemisphere is lower in elevation than the southern one (up to 6 km).

It also has far fewer impact craters and is much smoother and uniform all over.  The crust on the northern hemisphere appears to be much thinner than the southern hemisphere.  The surface mountains on Mars are just inactive volcanoes. Impact craters and basins are prevalent in Mars’s southern hemisphere.

Mars is believed to have ice underneath its surface – and there are also ice caps at the poles, the number of which changes depending on the seasons.

Surface Features of Other Planets:

The planets Jupiter, Saturn, Uranus and Neptune are gaseous planets. It’s mostly about their atmosphere. The gases get denser, hotter, and under greater pressure as you go further towards the center. These planets have no solid surface.

They all mostly have a liquid as a top layer and then the atmosphere. All these planets and their atmosphere, except the core, contain mostly hydrogen and helium in different states, such as liquid, solid, and gaseous. Apart from this, they also have ammonia and methane in some amounts.

Questions and answers:

Which of the planets in the solar system do not have a surface?

Answer:

1. Jupiter
2. Saturn
3. Uranus
4. Neptune