Space Part 1: Our Solar System: Earth

Earth:

Earth is the 3rd planet out from the sun; 93 million miles away (11,733 Earths).  Earth is the largest rocky body in our solar system with a diameter of 7,926 miles.  It is also the only known thing in the universe to support life; although many scientists believe that life has to exist elsewhere.  Our planet is dominated by nearly 7 billion human beings; our population is expected to reach 9 billion by 2050.  If we want life to remain on this planet for years to come, we need to get our population under control.

On a happier note, because Earth is our home, it is the most widely studied object in the universe.  Earth was formed about 4.54 billion years ago.  After the formation of the sun, the leftover gases and dust eventually accreted into the spheroid that is our planet.

As this picture shows us, that initial cloud of dust and gases that was our planet eventually came under so much pressure that it ignited, forming our star.  Therefore, the Earth, and all of the living things on it, are here because of the process of star formation.  Our planet, and everything in our solar system, depends on the energy of the sun in some way.

We can also thank the sun for helping the first organisms on this planet get energy.  As mentioned in an earlier blog of mine, some of the first lifeforms on this planet were cyanobacteria (blue-green algae); organisms that thrived off of energy obtained from the sun through the process of photosynthesis.

Some cyanobacteria!

Since those first life forms (whatever they were exactly), life on this planet has gone through some pretty serious ups and downs.  Through the billions of years that life has existed on this planet, there have been countless number of species; including five major extinction events.  It seems as though life has an extraordinary ability to adapt to changing circumstances.  We have found organisms on the bottom of the ocean, underneath the crust at the bottom of the ocean, in the driest deserts, in the freezing arctic, in salt beds, in briny water, and underneath glaciers.  All of these life forms give scientists hope for finding life elsewhere in the solar system and beyond.

Our planet is the one example we have.  It is the one thing we can base our observations off of.  Because of this, it is essential that we develop a greater understanding of the geological processes that control this planet.  In addition, the more we learn about the animals that live on this planet, the more we will understand the complexity of life that might exist in the universe.

However, for all of this to be possible.  We must protect the environment in order to be able to sustain the life that we already know exists here.  There is no point in exploring the rest of the universe if we cannot sustain ourselves on this planet.