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Where Earth is in the Universe

Welcome Fellow ExplorersHello reader, lets turn on our imaginations and strap ourselves to our office chairs or in whatever it is you are sitting on for a journey that begins right here on Earth. We are going to explore one of the great astronomical, cosmological, and quantifiable questions ever asked.

"Where is Earth in the Universe?"

To learn about where we are we will have to travel back in time to the very beginning of our universe and take a journey that will land us here in the present and then outward into the observable universe we see and detect with our modern day technology. From our own Solar System to the edge of time and space we will explore this question together and hopefully end up with at least a better understanding of where we are in the universe.

When primitive men peered out from the safety of their caves and into the night sky filled with the glowing brilliance of a multitude of stars that make up the canopy above, I wonder if they pondered the same questions we do today.Siemens Ultrasound Transducer I mean when you look up at night at the visible stars that shine on the clearest evenings you can only wonder if they asked themselves that very question, "Where am I in the Universe?" But the actual number of stars in the sky is probably greater than all the sand grains on all the beaches of earth. Trillions of stars litter the universe in all directions.

To gather information from the stellar movements across the sky on observable nights and to create shapes of familiar gods and creatures the ancient astronomers named the pictures they saw as they connected stars and we call those images constellations. Sailors use the north star Polaris to guide their ships at night keeping her to the right when sailing west and left when heading east.

A Brief History of Mans Understanding of the Universe:

The Greek philosopher Aristotle theorized that the Earth was at rest in the center of the Universe and all the things we see in the heavens orbited around Earth. The astronomer Ptolemy used this theoretical principle to understand the movements in the heavens and his books were used for 1500 years. This model was called the Geocentric Model and was also adopted later on by the Catholic Church.

Galileo (1564  1642) discovered that Jupiter had four moons using a telescope he made himself. The moons showed that Earth was not at the center of all motion in the Universe. Galileo supported the theory set forth by Copernicus that the Earth actually circled the Sun. This got Galileo (a Catholic Priest) into trouble with the Church and he was placed under house arrest for the rest of his life.

In The Beginning The Earth Was Void and Without FormBeyond the ink like blanket of night and the congregations of stars in the vast void we turn the dial of a radio or we switch on a television with only static. What we hear is the familiar hissing, that hissing is a microwave fingerprint revealing the violent distant past of our universe, made by a big bang at the beginning of time and space.

To know where we are in the universe we must look back at where we came from. Some 14.5 billion years ago all the mass and energy in the universe was compressed into an infinitely dense state heated to several trillion degrees. What followed was an expansion of energy a featureless mass of heat and energy rushed outward as matter and antimatter came into existence and annihilated one another giving the universe a push in its expansion. Matter tipped the scales in favor of a stable universe where we can exist. Since that initial Big Bang our universe has been expanding ever since.

In its infancy the Universe was a very hazy place and was formless. After a million years the background temperature of the universe dropped to (3k degrees above absolute zero). Soon the strong force began to form nuclei which then captured electrons to create hydrogen and some helium. This helped the universe clear the heated froth of the after glow from the big bang and suddenly the universe gave birth to light as the first hydrogen stars ignited to life forcing back the cosmic haze. Denser regions of heated gas pulled together through gravity and birthed into stars. Soon those stars formed into galaxies. We know that today's universe is still expanding. But we can see the background radiation of that ancient cosmic explosion called the Big Bang.

The matter of the universe collected into galaxy forms held together by the force of gravity. Gravities influence is felt all over the universe and integral to its structure. As we move outward from our own Galaxy and it's closest neighbors the Local Group we find ourselves in a tendril of galaxies strung into Super Clusters and the pattern repeats over and over like the nexus celluloid of a sponge's foamy surface.

Did You Know?Asteroids have moons! Asteroid moons orbit larger asteroids with more mass. In some cases the two asteroids are almost the same size.

Lagrange points are locations in space where gravitational forces and the orbital motion of a body balance each other. Lagrange points are often used by NASA's JPL Mission Teams to help navigate space probes from Earth to the other planets.

Most Science Fiction films and television shows depict the asteroid field as being a huge mass of many large and small objects made largely of stone and dust. These fields have to be navigated carefully because of proximity issues. But this couldn't be further from the truth about what our asteroid belt looks like

The asteroid belt though populated by asteroid families are actually not very close together at all. These fields can contain many objects but they are weakly held together by gravity floating out there in the spacial expanse between Mars and Jupiter. This is also true for space junk. Yes it is true that there is LOTS of junk out there, but. It isn't like that scene in Wall E where they have to bust through a cloud of coffee cups and cigarette butts.

Our Sun Sol:

The Sun is our home star. It has a mass of over 300,000 Earths. It is classified as a G2 yellow dwarf star. Our Sun produces nuclear fusion which releases tremendous amounts of energy through heat, light, radiation, electromagnetic energy, and electricity. Our Sun is in its prime of life phase being that it is still bright and this is a sign that it is in its main sequence phase of life. Hotter stars glow brighter where they dim with age and become red giants. Our Sun has a while before it uses up all its hydrogen and helium and ends its life as a white dwarf.

The Sun goes through cycles of activity called solar cycles. These happen when the Sun's electromagnetic field lines twist up because of the Sun's differential rotation. See the Sun is slighting squished because of the forces of mass and inertia. It is so massive that it's outer equator rotates faster than its polar caps. This causes the magnetic field lines to twist while the Sun rotates. Convection of electrified plasma below the Sun's surface creates large electrical currents that have a north and south dipole effect. Prominences break the surface of the Sun creating flux ropes. If you could see the entire filament we'd see that it is a large circle much like you see when you place a magnetic beneath a sheet of paper with iron filings on it. This process creates solar weather. When the convection happens Sun spots form, Soon flux ropes of plasma and electromagnetic energy rise off the surface of the sun and once in a while they become so energetic they explode outward in a solar flare sending electrified solar winds into the solar system.

The Four Inner Planets or the (Terrestrial Planets):

The four rocky worlds that call our inner solar system home are the Terrestrial Planets. They are dense worlds made mostly of rock, silicates, minerals, and metals like iron and nickle. Most of them have an atmosphere, (Venus, Earth, and Mars all have atmospheres) and all three have weathering on their surface. Most of them have impact craters from asteroid impacts. They also have tectonic surface features like volcanoes and fault lines.

Mercury 1st Planet from the Sun:

Mercury is the first planet we encounter as we venture outward into the solar system. At only 0.4 astral units or AU from the son it is the closest and smallest planet in the solar system being only a .055 Earths mass. Mercury has no moons and is dotted with impact craters, ridges, and rupes all caused by gravitational contraction from when Mercury was formed. Mercury has no atmosphere, if it did it was scoured clean by the solar winds produced by the Sun. Mercury is baked on its Sun facing side and freezing cold on the night side. Mercury's interior is mostly a thin mantle and a large iron core which makes up the bulk of planet. This iron core also produces an electromagnetic field much like Earths.

Venus 2nd Planet from the Sun:

Venus is very close in size to the Earth. Like the Earth it has a thick silicate mantle which surrounds an iron core, a thick atmosphere and geological activity. But there are striking differences between the Earth and Venus. Venus has no moon, and on Venus it is hot enough to melt led and the pressure at its surface is so dense it would destroy a space lander if we sent one. The Russians did just this with Venera 3 a reinforced lander which crash landed and was only able to take one picture before it was destroyed. Venus is covered in a thick layer of cloud which produces acid rain, Venus is so hot because of a run away greenhouse effect in the atmosphere, this makes Venus the hottest planet even above Mercury in the solar system. Venus has no magnetic field it is bombarded with solar energy constantly but because of its atmosphere it is absorbed and reflected back out into space. Though there has been no geologic activity detected on the planets surface it is believed to be geologically active since the atmosphere seems to be regularly replenished by gases released by what scientists think are volcanic eruptions.

Earth 3rd Planet from the Sun and Our Home:

Earth our home planet and the largest and most dense of all the inner planets and the one with current observable geological activity. It is also the only world we know of where life is known to exist. The reason is that the Earth orbits the Sun at just the right distance so that the element H2O or water can exist in liquid form. Because of this anomaly the chemical process to create life happened on Earth many millions of years ago. Life now inhabits almost every single environment on Earth. This solar orbit where life took hold is known as the Goldilocks Zone where conditions for life were just right. The earth is very geologically active with tectonic plate movements and volcanism. The Earth has a hydrosphere or ocean where much of the life on Earth exists. The oceans have tides and this phenomena caused by the Earth's Moon is what creates tide pools where it is believed in the primordial period before life collected the amino acid chains that began life. The Earth's atmosphere greatly differs from the other planets in the solar system. Life has altered the atmosphere significantly with 21% free oxygen. The Earth is also the only inner planet to have a large satellite (the Moon).

The Earth's Moon (Luna)

The Moon is our most familiar neighbor in space. It is also the only alien body our race has visited so far. We have sent probes to other worlds, but only on the Moon have men landed and walked upon its surface. The Moon is the largest satellite of any of the moonlit satellites in the Solar System as compared by its size to its host world Earth. It is also the second dense Moon in the Solar System after Jupiter's IO. It orbits in synchronous rotation with Earth showing Earth the same face and never its far side. It is the brightest observable object in the sky after the Sun; this happens even though its surface has a low reflectivity rate and is as dark as coal. It's importance has helped mankind keep track of months and the passage of years by it's regular cycles. It's gravitational power can be observed in the tidal forces seen in our oceans. It is said that this may have played a major role in evolution and beginning of life on Earth.