Our Solar system
Location of our Solar System is placed in the Milky Way Galaxy, a set of celestial objects, spirally shaped, with a diameter of about 100,000 light-years. It contains approximately 200 billions stars. Based on studies of radioactivity we can now assume with certainty that our Solar System was apparently formed about 4.5 billions years ago but for the Universe itself it is proven that is even older, twice that much, due to the order of occurrence: our Milky Way galaxy had to form before our Solar System was formed and the formation of galaxy itself took somewhat billions of years.
Astronomy telescope - view the planets yourself
History of understanding our Solar system
According to the Aristotle our Universe is spherical and finite. Both attributes indicating that the Universe has perfect shape with center. Of course, the planet Earth was believed to be that center.. But with the birth of the Renaissance many assumptions about the universe had changed.
It is only fair to mention three the most revolutionary scientists who had radically contributed to the different perception of the universe. Nicolaus Copernicus (1473 - 1543) who was the first person to formulate a heliocentric cosmology which displaced the Earth from the center of the Universe. The father of modern observationalastronomy, Galileo Galilei (1564 - 1642), who invented first advanced telescope and Giordano Bruno (1548 - 1600), whose cosmological theories were more advanced and controversial and who went far beyond the Copernican model with his believes. He claimed that the Universe is infinite and that there is infinite numbers of Suns. Each Sun was substantially a star which has proven to be still a valid theory. Due to his progressive claims he was sentenced to death by Roman Inquisition in 1600. He was burned at the stake but his believes still live on since were proven to be correct.
Solar system links
Modern theory of our Solar System
Nowadays we mostly follow surveys based on the Big Bang theory credited by very important scientist Edwin Hubble (1889 – 1953). Hubble found out, by his observations, that the Universe is continuously expanding. He discovered a formula which helped us calculate the real age of our Universe. Galaxy’s velocity is proportional to its distance, he discovered, so galaxies twice as far from us move twice as fast. One important consequence of his surveys is also that the Universe is expanding in every direction, which basically means that is has no center or that it’s center is somewhat “everywhere”.
Edwin Hubble biography
Planets of our Solar system
The constitution of our Solar System is made of many different celestial objects: planets, moons, numerous comets, asteroids, meteoroids, dust, gas and the only star - Sun, which also happens to be the richest source of electromagnetic energy in our Solar System. The well known difference between a planet and a star is in its motion: planets orbiting the Sun and moons orbiting the planets which gives an impression that Sun somewhat doesn’t move but that is just an impression. If the Universe is expanding, then all the objects out there change positions. We can classify 9 known planets into 2 different groups, according to their composition. Planets, closer to the Sun, are made of dense, rocky composition, like Mercury, Venus, Earth and Mars; planets is other group are mostly made of gases, due to the distance to the Sun. Jupiter and Saturn are far more massive and heavier than the Earth, although they are composed of hydrogen and helium. Uranus and Neptune aren’t so massive but they carry much ice in their configuration.