The Solar System
The known solar system consists of 1 star which is the Sun and is at the centre of our Solar System with the 8 planets and all the other bodies in orbit around the Sun as in the diagram below, all held in their orbits by the Sun’s gravity. Our Sun is just like all the other stars you see in the night sky, some are smaller and some larger, our star being classed as medium in size.
Our solar system
Our planets are split into 2 groups, the four inner Planets known as the Rockies and the four Outer Planets known as the Gas Giants, this relates to the makeup of these planets.
The four gas giants of the outer solar system
Astronomical Units of Distance
- The astronomical unit =149,600,000km (1.00AU), which is the distance between the earth and the sun.
- The light-year is a unit of distance. It is the distance that light can travel in one year. Light travels at a speed of about 300,000 km each second. So in one year, it can travel about 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometres.
- 1.00AU = 8.3 light minutes!
Size Of The Solar System
The size of the solar system was always based very roughly around Pluto’s orbit of the Sun which is an ellipse shape that ranges from 30 AU to 50 AU. But now, if dwarf planets are included, the size must relate to the orbit of Eris which ranges from 38 AU to 97 AU. Therefore, its average diameter is 135 AU, which should be the outer reaches of our Solar System. Many people find it difficult to relate to these figures. However, our solar system is an extremely tiny part of the Milky Way galaxy. If the diameter of the solar system (about 1 light day) is reduced to 1 cm, the diameter of the Milky Way (100,000 light years) would be 365 km. Compared to the size of the universe, our solar system is near infinitely smaller. It’s safe to say a grain of sand to the size of the earth isn’t even comparable to our solar system compared to the Universe.
Orbit Of Eris, one of the moons of Pluto and one of the outermost units that defines the size of our solar system
The following maps of the universe are taken from Atlas Of The Universe a site designed to give everyone an idea of what our universe actually looks like. There are nine main maps on this web page, each one approximately ten times the scale of the previous one. The first map shows the nearest stars and then the other maps slowly expand out until we have reached the scale of the entire visible universe.
The Universe Within 12.5 Light Years - Our Nearest Stars
This map shows all of the stellar systems that lie within 12.5 light years from us. The closest star to the Sun is only 7000 times further than the edge of our solar system.
The Universe Within 12.5 Light Years - Our Nearest Stars
The Universe within 250 Light Years - The Solar Neighbourhood
- Number of stars within 250 light years = 260 000.
This map is a plot of the 1500 most luminous stars within 250 light years. All of these stars are much more luminous than the Sun and most of them can be seen with the naked eye. About one third of the stars visible with the naked eye lie within 250 light years, even though this is only a tiny part of our galaxy.
The Universe within 250 Light Years - The Solar Neighbourhood: This map is a plot of the 1500 most luminous stars within 250 light years.
The Universe Within 5,000 Light Years - The Orion Arm
- Number of stars within 5,000 light years = 600 million
This is a map of our corner of the Milky Way galaxy. The Sun is located in the Orion Arm - a fairly minor arm compared with the Sagittarius Arm, which is located closer to the galactic centre. The map shows several stars visible with the naked eye which are located deep within the Orion arm. The most notable group of stars here are main stars in the constellation of Orion - from which the spiral arm gets its name. All of these stars are bright giant and supergiant stars, thousands of times more luminous than the Sun. The most luminous star on the map is Rho Cassiopeia and is 4,000 light years away, it is a dim naked eye star, but in reality it is a huge supergiant star 100,000 times more luminous than our Sun.
The Universe Within 5000 Light Years - The Orion Arm: This is a map of our corner of the Milky Way galaxy.
The Universe within 100,000 Light Years - The Milky Way Galaxy
- Number of stars within 100,000 light years = 200 billion
This map shows the full extent of the Milky Way galaxy - a spiral galaxy of at least two hundred billion stars. Our Sun is buried deep within the Orion Arm about 26 000 light years from the centre. Towards the centre of the Galaxy the stars are packed together much closer than they are where we live. Notice also the presence of small globular clusters of stars which lie well outside the plane of the Galaxy, and notice too the presence of a nearby dwarf galaxy - the Sagittarius dwarf - which is slowly being swallowed up by our own galaxy.
The Universe Within 100,000 Light Years - The Milky Way Galaxy: This map shows the full extent of the Milky Way galaxy - a spiral galaxy of at least two hundred billion stars.
The Universe within 500,000 Light Years - The Satellite Galaxies
- Number of large galaxies within 500 000 light years = 1
- Number of dwarf galaxies within 500 000 light years = 12
- Number of stars within 500,000 light years = 225 billion
The Milky Way is surrounded by several dwarf galaxies, typically containing a few tens of millions of stars, which is insignificant compared with the number of stars in the Milky Way itself. This map shows the closest dwarf galaxies, they are all gravitationally bound to the Milky Way requiring billions of years to orbit it.
The Universe within 500,000 Light Years - The Satellite Galaxies: This map shows the closest dwarf galaxies, they are all gravitationally bound to the Milky Way requiring billions of years to orbit it.
The Universe within 5 million Light Years - The Local Group of Galaxies
- Number of large galaxies within 5 million light years = 3
- Number of dwarf galaxies within 5 million light years = 46
- Number of stars within 5 million light years = 700 billion
The Milky Way is one of three large galaxies belonging to the group of galaxies called the Local Group which also contains several dozen dwarf galaxies. Most of these galaxies are depicted on the map, although most dwarf galaxies are so faint, that there are probably several more waiting to be discovered.
The Universe within 5 million Light Years - The Local Group of Galaxies
The Universe within 100 million Light Years - The Virgo Supercluster
- Number of galaxy groups within 100 million light years = 200
- Number of large galaxies within 100 million light years = 2500
- Number of dwarf galaxies within 100 million light years = 50,000
- Number of stars within 100 million light years = 200 trillion
Our galaxy is just one of thousands that lie within 100 million light years. The map shows how galaxies tend to cluster into groups, the largest nearby cluster is the Virgo cluster a concentration of several hundred galaxies which dominates the galaxy groups around it. Collectively, all of these groups of galaxies are known as the Virgo Supercluster. The second richest cluster in this volume of space is the Fornax Cluster, but it is not nearly as rich as the Virgo cluster. Only bright galaxies are depicted on the map, our galaxy is the dot in the very centre.
The Universe within 100 million Light Years - The Virgo Supercluster: The above map shows how galaxies tend to cluster into groups, the largest nearby cluster is the Virgo cluster a concentration of several hundred galaxies which dominates the galaxy groups around it.
The Universe within 1 billion Light Years - The Neighbouring Superclusters
- Number of superclusters within 1 billion light years = 100
- Number of galaxy groups within 1 billion light years = 240,000
- Number of large galaxies within 1 billion light years = 3 million
- Number of dwarf galaxies within 1 billion light years = 60 million
- Number of stars within 1 billion light years = 250,000 trillion
Galaxies and clusters of galaxies are not uniformly distributed in the Universe, instead they collect into vast clusters and sheets and walls of galaxies interspersed with large voids in which very few galaxies seem to exist. The map above shows many of these superclusters including the Virgo supercluster - the minor supercluster of which our galaxy is just a minor member. The entire map is approximately 7 percent of the diameter of the entire visible Universe.
The Universe within 1 billion Light Years - The Neighbouring Supercluster: The entire map is approximately 7 percent of the diameter of the entire visible Universe.
The Universe within 14 billion Light Years - The Visible Universe
- Number of superclusters in the visible universe = 10 million
- Number of galaxy groups in the visible universe = 25 billion
- Number of large galaxies in the visible universe = 350 billion
- Number of dwarf galaxies in the visible universe = 7 trillion
- Number of stars in the visible universe = 30 billion trillion (3×10²²)
This map attempts to show the entire visible Universe. The galaxies in the universe tend to collect into vast sheets and superclusters of galaxies surrounding large voids giving the universe a cellular appearance. Because light in the universe only travels at a fixed speed, we see objects at the edge of the universe when it was very young up to 14 billion years ago.
The Universe within 14 billion Light Years - The Visible Universe: This map attempts to show the entire visible Universe.
Cosmic Time and Scale
- If the solar system were the size of a table, the Andromeda Galaxy would lie at 10 times the distance to the moon, and the most distant galaxies would lie at 60 times the distance to the Sun.
- If we were to compress the time since the Big Bang into one year, and make the time of the Big Bang January 1.
- The Earth would be formed in mid-September.
- The mammals would appear on December 26.
- All human prehistory (from the first known stone tools) and history would have occurred in the last 1/2 hour of New Year’s Eve.
God Almighty mentioned in the Holy Quran that He created seven skies and that He adorned the sky nearest to earth with lights, i.e. stars, the basic units of the universe.
“Then He ordained them seven heavens in two Days and inspired in each heaven its mandate; and We adorned the sky nearest to the earth with lights, and made them secure: such is the ordaining of the Almighty, the All-Knowing”
[41:12]
“And, indeed, We have adorned the sky nearest to the earth with lights,”
[67:5]
Therefore, the seven skies or heavens are likely to be separate space-times beyond the limits of our universe or space-time (a sphere 14 billion light years across), the stars of which adorn the lowest of them.
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