astronomers (some of these moons are not natural satellites), one moon in Jupiter's influence is actually larger than Mars. It took over a billion and a half years for the dust matter and debris to fully clump together, forming the planets and moons we see today.
Some cosmologist believe our Moon was once a part of the Earth, that matter from the Earth was blown out into space after a large asteroid or one of the dwarf planets crashed into the Earth at a glancing blow, with this matter being accreted into its present mass as a natural satellite of the Earth (the Moon is very similar in chemical makeup and shares many of the same minerals as the Earth) That is a debate that will go on throughout time as there is no way of knowing for sure the actual events that led to the formation of our Moon.
Our Moon has an interesting anomaly in that it only shows one side of its self to the Earth. The rotation of the Moon is at exactly the right speed to always be facing in the same direction as it orbits around our planet. Another interesting fact is that the Moon is currently exactly the right distance from Earth to precisely block out the Sun during an eclipse, although in its initial formation it was much closer to Earth and has been slowly inching its self away from the Earth ever since. Without the Moon, the Earth's axial tilt would wobble wildly, greatly affecting the seasons and weather on Earth, making it a much harsher planet to live on.
Some believe there is an actual ninth planet in our solar system; it has been referred to as Planet X. For many decades Pluto was believed to be Planet X, but after the mass of Pluto was determined to be too small to have the gravitational effects exhibited on the gas giant planets, Pluto was discounted as Planet X. The purported mass of Neptune was later discovered to be incorrect, when the new mass of Neptune was calculated, the anomalies of the orbits of the outer planets was accounted for. Once the anomaly of the missing planetary mass and its supposed effects on the outer planets was accounted for, the thought of a Planet X has pretty much been a lost hypothesis among most cosmologists, although there are still believers in a Planet X, or by some, even the belief of a brown dwarf companion to our sun (NO!).
There is another dwarf planet, Eris, thought to be much larger in mass than Pluto and subsequently helped in the demotion of Pluto to that of a dwarf planet. Eris (discovered in 2005 by Mike Brown, Chad Trujillo and David Rabinowitz at the Palomar observatory) has a very eccentric orbit in the far reaches of the Kuiper Belt. The orbit of Eris takes about five hundred fifty Earth years to orbit the Sun at a distance ranging from thirty eight to ninety five times the Earth-Sun distance. As you can see, the orbit of Eris is way outside of and then well within the orbit's of the outer gas giants, making it a true anomaly in our solar system.
As do the planets in our solar system orbit around the center of the solar system (the Sun), our solar system also orbits around the center (black hole) of the Milky Way Galaxy. As you know, the orbit of the Earth takes about three hundred sixty five days (one year) around the Sun and our seasons change accordingly. On the same note, our solar system takes about two hundred fifty million years to orbit around the black hole at the center of the galaxy we reside in. This rapid orbit around the center of the galaxy comes with some 'baggage', IE the tilt of the Earth on its axis changes during the orbit, thus drastically affecting the climate on Earth. As the Earth slowly 'wobbles' on its axis around the galaxy, ice ages come and go and what is now considered mild or moderate zones on the planet can be rendered as very harsh conditions (normal climate change, such as during the Hourglass Effect).
THE SUN
The Sun is not only the center of our solar system; it is what nourishes all life on this planet. The Sun's warming radiation is what contributes to make the Earth a habitable planet, because the Earth resides at the precise distance from the Sun, IE just the right amount of radiation to warm the planet for liquid water, what is commonly called the 'habitable zone' (5).
Our star, the Sun, is a middle aged, main sequence, fusion reaction star and is classified as a G2 star (on the small side as stars go). The Sun is currently comprised of about seventy five percent hydrogen and twenty three percent helium, with the remaining two percent consisting of trace amounts of other elements. The core of the Sun approaches fifteen million degrees Celsius, while the corona is in excess of one million degrees Celsius The Sun's mass is about three hundred thirty three thousand times the mass of Earth, and comprises about ninety nine point five percent (99.5% is a very significant number) of all the physical mass of our solar system.
The influence of the Sun is not just confined to the eight planets, the Sun's magnetosphere is felt about twenty three and a half billion kilometers out. Just as the Earth's magnetosphere protects our planet from the Sun's excessive solar radiation, the Sun's magnetosphere protects our whole solar system from the traversing radiation in the Universe. The particles of the Sun's solar winds can be measured at a distance of thirty three and a half billion kilometers; the solar wind is then buffeted by the radiation flying throughout the Universe towards our solar system.
The Sun is a little over five and a half billion years old and will last about another four and a half billion years. That is when it will have depleted its hydrogen fuel (as a star ages, the rate of fusion is drastically increased) and will start to cool down as the nuclear furnace turns off. The core of the Sun will then consist primarily of helium atoms with much less mass than it currently has, as most of the mass in the conversion from hydrogen to helium is lost as radioactive and physical particles on the solar winds.
What drives our Sun is the nuclear furnace within, the nuclear fusion (8) of the hydrogen atoms creates the heavier helium atoms releasing massive amounts of energy as this heavier atom is created, and this nuclear fusion happens billions of times each second. Most of the resulting energy (particles of radiation) is then thrust off into space on the solar winds, with a very limited amount of this energy actually penetrating our atmosphere and thus radiating the planet with just enough warmth. When an excessive amount of this radiation (such as a solar flare) is able to penetrate our atmosphere (especially in the polar regions), the resulting ionization of the atoms in the atmosphere illuminates the sky with spectacular colors, what we in this hemisphere refer to as the northern lights.
In modern times, the solar maximum (when the Sun is most active) occurs in cycles of about every eleven years. Sun spots (dark areas) are actually a cool region on the Sun's surface caused by increased magnetic activity in one region. Unlike the Earth that has well defined lines of magnetic flux, the Sun's flux lines exit and enter the Sun at random points, sometimes in excess of other regions, thus resulting in the sun spots (increased gravity that holds the molecules and radiation close). A solar flare is caused when a large amount of energy is expelled from within the Sun, usually this happens when the strong magnetic regions (sun spots) collapse and release the excess energy that has been held in check.
These solar flares are comprised of radio waves, X-rays, gamma rays, photons and other particles; this radiation travels at an incredible speed away from the Sun on the solar winds (6). Solar astronomers refer to the massive discharge as a CME (coronal mass emission). The last major CME was in 1859, with the Northern Lights seen as far South as Chicago and Paris. If we were to have a similar massive CME today, there would be worldwide problems as most of the electrical grid and communications satellites would fail.
There are stars whose core is made up primarily of other atoms such as helium instead of hydrogen, but these are usually gigantic stars with a very large mass of helium or other gas at the core. Under exacting conditions, the tremendous pressure exerted by the gravitational pull of the large core will cause it to ignite the nuclear furnace (helium stars comprise only a small percentage of all the stars in the Universe, with hydrogen comprising the majority of stars) When these types of stars fuse the helium atoms, carbon (which is the building block of all life forms) is the end result.
This process is called a triple alpha process because it takes thr
ee helium nuclei to produce one carbon nuclei. The first part (of the triple alpha process) is two helium nuclei combining to form a beryllium nucleus which then subsequently fuses with another helium nuclei, finally forming the carbon nuclei. The process of combining atoms (fusion) in any star can only occur under tremendous core pressure (gravity) in conjunction with high intensity nuclear force. Helium stars have such mass that their core temperature is in excess of one hundred million degrees Kelvin. The end of life for a helium star is usually that of a white dwarf, with the resulting core, as stated, consisting primarily of carbon and oxygen atoms.
Neutron stars (55) are an even rarer occurrence than a helium star, the neutrons are compressed to the point that a liquid like material is formed of the neutrons. The liquid like material has properties that are highly conductive of electrical energy (a metallic property), thus creating a very large and powerful magnetosphere, the largest in the Universe. Most astronomers believe all black holes are created by the collapse of a neutron star. (??)
The death of our Sun will be of little fanfare