Astronomy and Space Science

Earth is the second solar planet from the Sun and therefore the only solar-system body known to harbor and support life. About 29.2 percent of the earth’s surface is water containing oceans and continents. The remaining portion is solid earth including mineral layers, deserts, plateaus, and mountains. The crust of the earth is divided into two main sections: the continental crust and ocean crust. The continental crust is composed of continents that are in extended continental drift and the ocean crust is the sea floor.

A variety of physical and chemical processes have occurred on earth’s crust to give it the composition that it has today. Many elements and compounds are derived from fossils and ancient rocks and these provide evidence for the planet’s geology, atmosphere, and outer space environment. Geologists classify the earth based on their composition of tectonic strata.

Earth obtains its atmosphere from its orbit around the sun. About 90 percent of the earth’s total annual output of heat comes from its atmosphere. This heat radiates out into space and heats the uppermost layers of the earth’s atmosphere, making the planet hot. The Earth obtains a protective envelope of air that protects it from the solar wind, causing its chilly outer surface to be cool. A relatively thin film of water vapor is also emitted into space, cooling the earth further.

About 4.5 percent of the earth’s total volume is solid matter. This consists mainly of rock and a few ocean-covered icebergs. The rest of the earth consists mostly of water and other ocean-related substances. The earth’s interior is filled with great quantities of gases, which are trapped inside the Earth’s crust. Particles of dust, minerals, and gases from space also make up a significant proportion of the earth’s solid surface.

Astronauts visiting the moon and Mars have found that these celestial bodies offer far more diversity in their composition than scientists had previously believed. On earth, animals and plants appear very diverse, but on these celestial bodies, the diversity is incredibly pronounced. In fact, many types of plant and animal life have been discovered that were previously unknown. We are learning more about the composition of Mars and the moon every day.

Astronomy and space science have given us many fascinating new facts about our earth and other heavenly bodies. Although many of these discoveries are still in the discovery stage, we have been able to take a good look at the moon, Mars, and the planets in our solar system. This has allowed astronomers to discover phenomena that would not have been expected. By better understanding our earth’s place in the outer space, we may learn to deal with problems here on earth that would have otherwise been impossible.