This is an artist's rendition of Earth's primordial environment and the beginnings of life.
Windows Original

Earths Primordial Environment

In the beginning, Earth had a hydrogen based atmosphere. Since molecules like methane and ammonia were included it must have been a pretty smelly place! In time, the early atmosphere of Earth changed from a hydrogen dominated one to one which contained lots of oxygen. Examples of those molecules include carbon dioxide, and water vapor. In its primordial state Earth's atmosphere resembled other primitive atmospheres.

Jupiter's atmosphere is an example of what such primitive atmospheres must have been like. This is because Jupiter is so big it has enough gravity to hang onto every molecule. So scientists think that Jupiter's atmosphere today is representative of the early atmospheres of the smaller planets.

Certain chemical reactions require energy to make them go. That energy can come from ultraviolet (UV) light or lightning which can link small molecules together to make larger ones. The Miller-Urey experiment showed that ultraviolet light plus lightning in a hydrogen-based atmosphere can produce interesting long chemicals which form the foundation of living cells.

Earth's early environment was conducive to this process because the early atmosphere did not provide protection from ultraviolet light. On Earth today, the ozone layer absorbs almost all but the longest wavelengths of UV. On the early Earth, there was little free oxygen, so UV from the sun fell directly onto the surface of the Earth.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

What’s That Mineral?

Spotting minerals is fun! There are many different types of minerals. Each has a different name and special traits. You can learn more about minerals by looking closely at them to understand their special...more

Quartz

This mineral is called quartz! Sometimes it looks white like milk but usually it looks clear like glass, sometimes with a little pink or gray tinge of color. You can find crystals of quartz in many different...more

Mica Minerals

Mica minerals make some rocks sparkle! Look for them in your igneous and metamorphic rocks. Do they make your rocks sparkle? They break into flat plates because they have cleavage. ...more

Feldspar

This is a feldspar mineral! Look for it in igneous rocks where it looks like white or pink crystals. You might find it in other types of rocks as well. ...more

Olivine

The mineral that is green is called olivine! Look for it in igneous and metamorphic rocks. In this picture, olivine is filling a hole in the igneous rock. ...more

Type of Minerals

There are at least 2000 minerals on Earth. That's a lot of minerals! But you don't need to know all of them to spot the minerals lurking in the rocks of your backyard. That is because only a small number...more

What Is a Mineral?

Minerals are the building blocks of rocks. There are many different types of minerals. All of them are solid and all are made of atoms of elements. Minerals can grow even though they are not alive. Most...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA