- Attachment: A Spiral Galaxy
- Then the Sun and the entire Solar System is traveling around the center of the Milky Way Galaxy at 486,000 miles per hour. Our galaxy and the Andromeda Galaxy are approaching each other at 670,000 miles per hour. Together with a Local Group of Galaxies we are approaching the Virgo Cluster of Galaxies at 2,370,000 miles per hour. That is our closing speed, our galaxy is traveling at 335,550 miles per hour in that direction. This whole Cluster of Galaxies is approaching the Coma Cluster of Galaxies at 16,000,000 miles per hour.
- These are all “approaching” galaxies because they are all gravitationally connected. Outside the gravity bounds of these galaxies is outer space that is expanding between galaxies. The rate galaxies are receding is known as Hubble’s Constant and it is 50,400 miles per hour per each million lightyears distance in separation. The further a galaxy is away from us, the more expanding space there is between us, the faster the galaxy is receding away from us.
- A galaxy that is 100 million lightyears away is receding at 5,400,000 miles per hour.
- A galaxy that is 10 billion lightyears away is receding at 504,000,000 miles per hour. That is 75% the speed of light. If we look over the opposite horizon at another galaxy that is 10 billion light years away receding at the same speed, the two distant galaxies are receding from each other at 1,008,000,000 miles per hour. That is 150% the speed of light.
- The Universe is only 13.7 billion years old. The two distant galaxies are 20 billion light years apart. The space between them is expanding 50% faster than the speed of light. Therefore no light, or any matter, or radiation, could ever be exchanged between them. And, it never will.
- Remember, the galaxies themselves are not traveling faster than the speed of light. It is the space between them that is expanding with a cumulative effect of separating them faster than the speed of light.
- Also remember, that the light that reaches us today can not be older than 13.7 billion years. But, it has been traveling for 13.7 billion years to reach us and the Universe has been expanding all that time. Our Observable Universe is 13.7 billion years in all directions, but, the actual “Observable Universe” that we will have to wait to see because the light that has not reached us yet traveling at 670,616,529 miles per hour, is 45 billion lightyears away in all directions.
- Here is a thought experiment: If Isaac Newton had blasted off the Earth on a spaceship traveling at the speed of light, we could observe him alive today through the telescope. He could be waving at us through the porthole of the spaceship at the same time we know he is buried in Westminster Abbey. In the same way we see galaxies as the looked billions of years ago. We have only imaginative ideas as to what they really look like today?
- Back to our Solar System orbiting Sagittarius at 486,000 miles per hour. The Constellation ”Sagittarius the Archer” is the “teapot” constellation in the southern night sky. Right at the top of the spout of the teapot is the center of our galaxy. We are 26,000 lightyears away from that center. Traveling in a circle around the center takes 220,000,000 years. It is a perilous journey through space. During our lifetimes we do not get very far around. But, during the lifetime of our Solar System, 4.5 billion years, we have made the trip 68 times.
- In one complete trip we have to pass through the 4 spiral arms of the Milky Way disk. We also have to bob above and below the disk about 4 times. Each bob gets us above and below the disk by about 200 lightyears.
- This is a perilous journey. We encounter many dangerous environments in space. Our Mother Earth has a very broken record of all it has encountered. The rocks and records have been constantly recycled by plate tectonics, seasonal and weather erosions. However, a better record can be found on the Moon. If we can get there and read the record, its rocks have been undisturbed for eons.
- The Moon’s sub-terrain certainly contains a record of our past journeys through the spiral arms of the galaxy. These arms are standing waves of denser regions where stars and gas come closer together. As our Solar System passes through each arm we are like a surfer riding an ocean wave. If our speed is just right we get pushed along with the wave. We could ride the wave for 10,000 years or more.
- Our Sun is richer in heavy elements than stars in our neighborhood. Also, the Dwarf Planet Sedna has an elongated orbit not explained by our Solar System physics. This could be evidence that our Sun was once closer to the center and once road such a wave. If we could get to the Moon we could find confirming evidence of our surfing background.
- The Orion Nebula is only 1,000 lightyears away. It is full of new stars and massive stars. Many supernovae have exploded in this region in the distant past. The Earth would have been much closer at times in its journey around the galaxy. X-ray radiation from these supernovae could have been responsible for depleting our ozone layer. Ultraviolet radiation could reach the surface with Cosmic Rays causing massive environmental change and mass extinctions of life on Earth.
- Discovery of the isotope iron-60 in ocean sediments suggests just such an event occurred several million years ago. The half life of iron-60 is 2.6 million years. It is commonly expelled material of supernovae, but, it is not found in any natural processes on Earth. Again, the Moon should have the answers. Astronomers hope to find other exotic isotopes like krypton-83 and xenon-126. The lava flows on Moon’s surface can be dated precisely by measuring decay of radioactive elements. Could the Moon’s records match the Earth’s records of mass extinctions?
- Today, our journey is in a relatively empty patch of space, with a hydrogen atom per 5 cubic centimeters. There are denser patches of space around the galaxy that have 1,000 molecules per cubic centimeter. Passing through these denser regions could have the effect of deforming our electromagnetic shield that encircles the Earth. This in turn could create reflective clouds and dust aerosols that would block the sunlight and trigger a global ice age every few hundred million years. We know a “Snowball Earth” era did occur some 700 million years ago. Again, the Moon could tell us Earth’s tale.
- Could our galactic odyssey be repeated encounters as we journey around the galaxy? Our Solar System today is north of the galactic plane. Could we be headed for danger? An announcement will be made shortly, stay tuned.
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707-536-3272, Friday, December 9, 2011
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