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Astronomy and astrophysics

Welcome to the homepage of astronomy and astrophysics. If you want to know why does the sun illuminate or out of what the earth has originated, then have a look on this website

Chapter 1: The Big Bang and the formation of matter

The most known theory about the orgin of the universe is the Big Bang. The Big Bang took place 15,000,000,000 years ago. This theory says that something which was as big as an atom and which was very hot explosed. After 10-35 there were quarks (particles which forms protons and neutrons). There were also antiquarks and when the quarks and the antiquarks came together they have destroyed each other and they only left energy (often gamma radiation thus photons). The temperature was 1027 degrees. One theory says that there was more matter than antimatter, if it was not so now there were not any stars or planets in the universe. But it is a riddle, because the theory of the Big Bang tells us that the Big Bang was symmetrical and that means that there should be as much matter as anitmatter. Another theory says that at the beginning there was as much matter as anitmatter, but the antimatter had decayed very fast. After 0.0001 seconds mesons, protons and neutrons have been formed. The temperature was 1012 degrees. After 3 minutes protons and neutrons fused to ions and when it was colder this ions caught electrons and so the first atoms were born. But this happend 300,000 years later when the temperature was only 3,000 degrees. The first elements were hydrogen and helium. In all this processes there were much energy. So the matter like we know it today was born. Foremost since the Big Bang there is space and time and during the Big Bang the unified power has been divided in the four fundamental powers (gravity, electromagnetic power, weak power, strong power). The unified field theory will be discribed in the next chapter.

Chapter 2: The unified field theory

The unified field theory is for modern physics the most important problem. This theory says that after the Big Bang only one unified power has existed. This GUT-Power (Grand Unified Theory) was divided into four fundamental powers.

The four fundamental powers
powerrange strengthappearance
strong power 10-15 m 1 between quarks
electromagnetic power infinite 10-2 between charged particles
weak power 10-15 m 10-13 between leptons (neutrinos, elecrons)
gravity infinite 10-38 between all particles

Today we try to bring the four powers together. It has been discovered that a symmetry has existed between the electromagnetic power and the weak power which has broken. It is important to know that the W+-, the W-- and the Z0-particles are the exchangeparticles of the weak power. In our universe there is the higgs field, which unifieds with the field of the weak power. With high energy it is possible to destroy the higgs field and the exchangeparticles of the weak power are then free, they behave like photons and do not differ from them. For this discovery S. Glashow, S. Weinberg and A. Salam got the noble price. In an experiment in the CERN (Conseil Européenne pour la Recherche Nucléaire), in the proton-antiproton-collider this particles were found and so the electricalweak power was proofed. Now phycisists work to find a connection between the electroweak power and the strong power.

Chapter 3: galaxies

The formation of a galaxy

After teh Big Bang theory galaxies were formed 1,000,000,000 years ago. There are today different theories about the formation. One of this theories says that stars were formed of much gas, that they have drawed each other because of their gravity and that then galaxies were formed. The formation of a star will be described in the next chapter. Another theory says that there was much gas which has drawed each other. They came closer and closer and some of them formed stars. This stars circled round in the outer regions of the protogalaxy and they brought this protogalaxy to illuminate blue. This protogalaxy was much brighter than our galaxy. After a certain time next stars were formed of the gas in the center of the protogalaxie and then it was a galaxie.

Types of galaxies

Andromeda galaxyThe Milky Way

There different types of galaxies. Our galaxy is the milky way a spiral galaxy. She has got a diameter of 100,000 light years and has got four spiral arms. This form of galaxy is the most beautiful I think, because it is a disk of stars which illuminate the gas of the galaxy. Galaxies like this were formed when the gas cloud they came off has rotated. This rotation made it impossible for the gas cloud to go together, because of the centrifugal power and so not the whole gas could form stars. This galaxies can consists of a few billiard stars. The half of the stars in our galaxy are multiple stars. The single stars circles around one center of gravity. The next big galaxy is the Andromeda galaxy (M 31) which is 2.2 million light-years (1 light year is the distance which the light go throught in one year; 9,460,000,000,000 km) away and she is even bigger than our galaxy. Another typ is the dwarf galaxy which contains only a few million of stars. The biggiest galaxies are the elliptical galaxies. In this galaxies and in the dwarf galaxies there is not any gas. There are also irregular galaxies which has not got any symmetric form.

Galaxy clusters and super heaps

In the universe there are galaxy heaps with many galaxies. The heap where the Milky Way and the Andromeda galaxy are is the local group. This two galaxies are the biggiest and most massively galaxies of the local group and the dwarf galaxies are around this two big spiral galaxies. The local group contains 26 galaxies. She has got a diameter of 4 million light-years. There also super heaps with many galaxiy heaps. Super heaps are the biggiest knows structures in the universe.

Chapter 4: Stars

The life of a star

After 500 million years galaxies were formed and after 1,000,000,000 years gas and particle cloud were formed in some regions of the universe. The majority of the gas was hydrogen and a little bit of helium. This atoms came closer because of the gravity. They have begun to condense and so they have formed a protostar. In a protostar are not any nuclear fusions, but a protostar emits infrared light and radio waves which are able to pass the gas and particle clouds around the protostar. Some stars which have got to little mass for nuclear fusions stay in this state, but the gas and particle cloud disappear and they illuminate very weak. Star like this are called brown dwarfs. In other stars like our sun nuclear fusions begin after 10,000 years and now it is not any longer a protostar, but it is a star. But we should not despise brown dwarfs, because we think that they and black holes are the matter which misses in the calculations of phycisists. Because in the past scientists have done their calculations only with the matter which illuminates. But when this calculations does not corresponded to the Big Bang theory the phycisists began to search dark matter. For many million years the gas and particle cloud is around the new star. After a certain time planets can be formed from this gas and particle cloud like it was in our solar system. Up to this point the orgin of every star is the same, but now we must divide the star into classes. When a star has got a bigger mass than another star the nuclear fusions in star this are faster than in the smaller star. The consequence is that this star is hoter, but he lives shorter than a star with less mass. The spectral classes (star classes) are described at the bottom. There exists two types fusion reactions which we can find in stars. the first is the proton proton cycle (p-p-cycle) and the other other is the carbon nitrogen oxygen cycle (CNO-cycle). Only one of this cycles is in a star. The most massively stars are blue stars. Their surface temperature is about 25,000 Kelvin and they live only 10 million years. Our sun should live about 10,000,000,000 years and also red stars exists which live 100,000,000,000 years. The life exspectancy of a star depends on how fast the hydrogen is transformed into helium. When a star begins to burn helium then he begins to die. Our sun exists since 5,000,000,000 years. In 5,000,000,000 years, when the whole hydrogen in our sun is transformed into helium our sun will become a red giant. This red giant will be so big that Mercury, Venus and our Earth will be destroyed. Up to this time we need another planet to live on. After all this the red giant will become a white dwarf. A white dwarf is an object which is so dense that one cubic centimetre weighs about one ton. This white dwarf will be much smaller than our sun today, but its gravity will be much bigger than the gravity of our sun, because of the high density. When this white dwarf will loose his whole energy after a certain time he will be a black dwarf. When a star has got a mass which is 1.4 times the mass of our sun then it exploses during its death and this explosion is called supernova. Then it comes to a collaps and the core of the star becomes compressed and the end the star exploses. The final product depends on the mass of the star. One possibility is a neutron star which is so dense that one cubic centimetre weighs 300,000,000 tons and the other possibility is a black whole with a singularity where our physical laws do not matter and an infinite density. Even the light with a speed of 300,000 kilometres per second cannot escape from a black hole. Neutrons star and black holes are described at the bottom. Supernovas are so important, because during a supernova new elements are formed. The reason why stars collapse when they have transformed the whole hydrogen into helium is that this fusions thwart the gravity so we have got a balance, but now when there are not any fusions there is not any balance. During the normal life a star cannot explose, but it cannot collapse, because there is a balance. There are three possible ends for a star: a white dwarf, a neutron star and a black hole. Our sun is not a star of the first generation, because we can find heavy elements from other supernovas in our sun. Otherwise the earth would not exist. Stars of the first generation consists only of hydrogen.

The proton proton cycle

In the proton proton cycle in the sun it happens that because of the compression two protons are hold together for a short time. In this time one of the two protons decays into a neutron. A positron and neutrino are emited. This connection of one proton and one neutron is called deutrium (heavy hydrogen). When another proton hits this deutrium ion we have got helium-3 (two protons ans one neutron). Then two helium-3 ions come together and we have got the final product helium-4 (two protons and two neutrons) an two free protons. If you want to know more about nuclear physics have a look at the homepage of nuclear physics.

proton proton cycle

The spectral classes

Different stars has got different masses. When the mass is bigger then also the gravity is higher and the fusions must go faster to thwart this high gravity. A star like this is hoter than our sun, but it lives much shorter. 7 spectral classes exists: O (blue), B (blue-white), A (white), F (yellow-white), G (yellow), K (orange), M (red). The sentence says: Oh be a fine girl, kiss me. Star of the class O are the most massively and they are blue because of the high temperature of 25,000 Kelvin. Their life exspectancy is amoug 10,000,000 years because of the fast transformation of hydrogen into helium. The diameter of a star like that is a few million kilometres. A goog example for such a big star is Spica which is 275 light-years away and which has got a diameter which is eight times so big as the diamter of our sun. The coldest stars are stars of the class M with a temperature of 3,000 Kelvin. Their life exspectancy is 100,000,000,000 years. Our sun is in the class G. This means that our sun will live amoug 10,000,000,000 years. The most stars live on the main row of the Hertzsprung-Russel-Diagram, which goes from top left (blue over giants) tp bottom right (red dwarfs).


Neutron stars

Neutron star are formed during supernovas. They have got a density of 300,000,000 t/cm3 tons per cubic centimetre. Neutron star are not made of atoms, because in an atom there is much space between the atomic nucleus and the atomic shell. The atomic nucleus has got a diameter of 10-14 metre and the atomic shell has got a diameter of 10-10 metre. This means that the core is 10,000 times less than the shell, but 99.99 % of the mass are in the atomic nucleus. If you want to know mare about atoms and atomic nucleus look at the homepage of nuclear physics. The density in an atomic nucleus is as high as the density of a neutron star. A neutron star do not consists of atoms, but he consists of free neutrons, protons and electrons. The core of a neutron star consists of quarks, particles which forms protons and neutrons. This core is denser than the rest of the neutron star, because like in an atom there is space between the quarks in a proton or in a neutron. But in the core of the neutron star the protons and neutrons divided into quarks which lies one on the other and so the density here is amoung 1,300,000,000 t/cm3 tons per cubic centimetre. Around this core there is neutron fluidity with protons and electrons which superconducting and frictionless. Around this fluidity there is a crust which is 1 kilometre big and which is made of heavy neutron-rich atomic nucleus and free neutrons. The last thing around the whole neutron star is the atmosphere which is also made of heavy neutron-rich atomic nucleus. In neutron stars electrons and protons fuses to neutrons and a neutrino is formed during this process. It is an inverse beta decay. If you want to know something about the beta minus decay you can do it on the homepage of nuclear physics. Neutron stars which rotate very fast are called pulsars, because they emit radio waves. On every hemisphere there is a point where they have their source. Because of this radio waves it is possible to recognize neutron stars, because they diameter are 10 to 20 kilometres. Neutron stars also emits X-ray. Neutron stars have got magnetic fields with 100 million Tesla. When somebody should live on a neutron star it will be strange, because the escape velocity there is about one half of the speed of light, so it is possible to see the other side of the neutron star. Mountains on a neutron cannot be higher than 1 centimetre, because of the high gravity.

neutron star

This photo was taken by the Hubble Space Telescope and the white arrow shows a single neutron star. This photo is in the reach of the visible light.

neutron star

Black holes

Black holes are formed during a supernovas of very massively stars and in a singularity of a black hole where our physical laws do not matter the density is infinite. Black holes has got a horizon of events and when an object reachs them it cannot escape from there. Not even the light with a speed of 300,000 km/s can escape from a black hole. This is the reason why it is called black hole and when the light cannot escape it is invisible so black holes can be only proofed indirect. We suppose that the center of our galaxy is a black hole. When a shuttle for example will fall into a black hole it will become longer and longer and in the end it will break. When somebody goes closer to a black hole the time goes slower for him. The frequency of the light of a star which goes closer to a black hole will become lower and lower and this is called red shift, so the star will look red. Today we dicuss if black holes are time tunnels and if we can do time travels with their help. But if we want to travel throught we must be careful, because it will deadly for the traveller if he toughs the singularity. With the help of such worm holes it will be maybe possible to change things in the time, but it can have devastating consequences. There are also theories that parrallel universes exist which we can reach throught worm holes. When it will be possible to travel to other universes it will be possible to travel very long distances in our own universe, too. For example our next star, Alpha Centauri which is 4 light-years away. If we should travel with the speed of light it will take 4 years. But in our universe are also distances amoung millions or billiards of light-years. With the help of worm holes we can crook the space so strong that we can travel very long distances in a few seconds.

Chapter 5: Our solar system

Our solar system contains nine planets. Looking from the sun it is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Between Mars and Jupiter there is a belt of asteroids. This are asteroids which fly around the sun. Mercury, Venus, Earth, Mars and Pluto are terrestial planets, so they are solid. The four other planets are gas planets, but they have got a solid core. This planets have belts. In the following texts I will discribe all this planets.

The Sun


Our sun is made of certain layer. The core of the sun is the burning zone where the fusions take place and hydrogen is transformed into helium. The temperature here is 15,000,000 degrees. What we see is the photosphere. She has got a granular structure, because of the rise of hot gas from the inner regions of the sun. The temperature is 6,000 Kelvin. Here also the sun-spots. The reason are magnetic fields on the sun. They change in an eleven-year cycle. At the beginning of this cycle there are not any sun-spots on the sun, but during this eleven years there are more and more of this sun-spots. This sun-spots appear always together, because the magnetical lines of flux leave the sun in one sun-spot and enter them in another sun-spot. The dark places of this sun-spots are called umbra and the brighter border is called penumbra. The temperature of the umbra is 4,500 degrees and the temperature of the penumbra is 5,500 degrees. Over the photosphere is the chromosphere. She is made of thin gases. The temperature is about 4,000 to 50,000 degrees. Over the chromosphere we find the last layer of the sun, the corona. She is made of thin gases, too. The temperature here is even 2,000,000 degrees. This is a phenomen, because the corona is farer away from the burning zone than the photosphere or the chromophere, but she is hoter. The corona makes the solar wind. The solar wind consists of protons, heavy ions and electrons which have influence of the magnetic fields on Earth and on other planets, too. When this particles go into the atmosphere of the Earth we can see beautiful color effects in the sky, who are called polar light.

Data to the Sun
diameter at the equator 1,392,000 km
mass 1.989 * 1027 t
density 1.41 g/cm3
maximum surface temperature 6,000 degrees
minimum surface tmeperature 4,500 degrees



Mercury is a very hot planet, because he is very near at sun, but the roation period is 58 days, so he becomes cold on the side which is not exposed to the sun. He has got a very thin atmosphere of hydrogen and helium. Because he is so close to the sun he gets 4.7 times so much heat, light and other radiation as the Earth. With a diameter of 4,878 kilometres he is smaller than the Earth (12,758 kilometres diameter). His core which consists of iron and nickel has got a diameter of 3,600 kilometres and so he is bigger than the Moon. Around the core there is a rock coat which 600 kilometres big and then there is the crust with 66 kilometres big. Mercury is full of craters like the Moon. The biggiest crater has got a diameter of 625 kilometres and is called Beethoven. This craters are from planetesimales which Mercury caught throught his gravity. Because of this impacts lava came up which become cold. In the last 3,500,000,000 years Mercury does not change, because there are not many geological activities. The only discovery which was made by the space prob Mariner 10 between 1974 and 1975 were heat pols which lies on the opposite of each other. This heat poles are volcanical activities under the surface. The space prob discovered a weak magnetic field. Propable Venus, Earth and Mars looked at the beginning of their lives like Mercury today. The surfaces of Mercury and the Moon look very similar, but when we look into the inner regions there should be processes which were different during the formation of Mercury and the Moon. Mercury has got long grooves which are a few kilometres long and the Moon has not got any grooves like that. Propably they were formed during the warming and colling of the inner regions of Mercury. Another reason for this grooves might be that the gravity of the sun slows Mercury's rotation.

Data to Mercury
diameter at the equator 4,878 km
mass 3.303 * 1020 t
density 5.43 g/cm3
day (rotational period) 58.65 days
mean distance to the Sun 57,910,000 km
year (period) 87.97 days
orbital velocity 172,410 km/h
inclination of axis 2 degrees
maximum surface temperature 427 degrees
minimum surface temperature -212 degrees
moons 0



The surface and the structure of Venus is very similar to the surface and the structure of Earth. The first thing is that both planets are nearly of the same size, what you can see in the table. The second thing is that the core of Venus, with a diameter of 650 kilometres, and its coat are very similar to the core and the coat of Earth. The size is also nearly the same. Both cores consists of iron and nickel. The crust of Venus is 60 kilometres big and it is double so big as the crust of Earth. The atmospheres are different, too. The atmosphere of Venus consists of carbon dioxide (CO2). The atmospheric pressure of the atmosphere of Venus is 90 times as high as the atmospheric pressure of the atmosphere of Earth. On Venus it often rains sulphuric acid (H2SO4). When somebody looks at Venus he could not see the surface, because the atmosphere is so thick. The reason why the temperatures on Venus are higher than on Mercury is that the atmosphere of Venus contains very much CO2 and it is the greenhouse effect. There were a few space probs which have visited Venus for example Mariner 2, 5 and 10 and Venera 1 to Venera 16. This space probs should measure the speed of the wind and the structure of the surface. In the upper layers of the atmosphere the speed of the wind is about 360 km/h and in the lower regions it is about 3.6 km/h. Big pieces of the planet are plains and only some region lie lower. The space probs have found indications for erosions and they have discovered that the surface is covered in very small rocks.

Data to Venus
diameter at the equator 12,102 km
mass 4.869 * 1021 t
density 5.25 g/cm3
day (rotational period) 243.01 days
mean distance to the Sun 108,200,000 km
year (period) 224.7 days
orbital velocity 126,110 km/h
inclination of axis 177.3 degrees
maximum surface temperature 482 degrees
maximum surface temperature 446 degrees
moons 0



For us Earth is better known as all the our planets, because we make experiments on her ourself and we need not any space probs. The core of Earth consists of iron and nickel which is metallical in the inner regions and liquid in the outer regions. The inner core has got a diameter of 2,500 kilometres and the outer core is 2,200 kilometres big. The next layer is the coat which is 2,900 kilometres big. Then we have got the crust which is 30 to 40 kilometres big, but in the oceans the crust id only 5 kilometres big. The last thing is the atmosphere which makes life on Earth possible. 79 per cent of the atmosphere are nitrogen, 21 per cent are oxygen, 0.93 per cent are argon and other tarck gases like carbon dioxide (CO2) and helium. Because the atmosphere is not thin she holds the heat. After the industrial development there are more gases in the atmosphere which make the greenhouse effect. This are carbin dioxide (CO2) and nitrogen oxides.

Data to Earth
diameter at the equator 12,756 km
mass 5.976 * 1021 t
density 5.52 g/cm3
day (rotational period) 23.94 hours
mean distance to the Sun 149,600,000 km
year (period) 365.26 days
orbital velocity 107,250 km/h
inclination of axis 23.45 degrees
maximum surface temperature 58 degrees
minimum surface temperature -89 degrees
moons 1



The diameter of Mars is only the half of the diameter of Earth, but Mars is similar to Earth. This core consists of iron and nickel and has got a diameter of 3,000 kilometres. Around the core there is the coat which consists of silicates and which is 1,800 kilometres big. The next layer is the crust which is 100 kilometres big. The atmosphere is in the majority of carbon dioxide (CO2). Because Mars is farer from the Sun than Earth he has got a longer period. Because of the inclination of axis on Mars there seasons like on Earth, but it is colder. The Mars is red, because large pieces of the surface are covered in iron and silicon and so there is corrosion. This ferric oxide particles go up so the the sky looks pink. Mars is a desert planet. On this planets are many volcans which are much higher than on Earth. The poles of Mars are covered in ice, which consists of carbon dioxide (CO2) and water. The space probs which landed on Mars were Mariner 4, 9 and Viking 1. They have made very good photos of the volcanos and craters, so that even a full map of Mars exists. Today Mars becomes more and more interesting for space travel. NASA will land there with a manned spaceship until 2020. A few years ago NASA said that they will land with a manned spaceship between 2008 and 2011, but now they need more time. Before can happen Mars must be known better. In the moment Mars Global Survoyer and Mars Odyssey search Mars. Another important space prob was Mars Pathfinder. We will also examine if there is any life in this ice, because in former times Mars looked like Earth today.

Data to Mars
diameter at the equator 6,786 km
mass 6.421 * 1020 t
density 3.95 g/cm3
day (rotational period) 24.62 hours
mean distance to the Sun 227,940,000 km
year (period) 686.98 days
orbital velocity 86,870 km/h
inclination of axis 25.19 degrees
maximum surface temperature 27 degrees
minimum surface temperature -126 degrees
moons 2

The asteroid belt


Between Mars and Jupiter there are asteroids which circle round the sun like all other planets. Many thousends of them are known today, but only few of them has got a diameter which is bigger than 200 kilometres. Because of the gravity of Jupiter it is not only one ring of asteroids, but there are a few rings of asteroids. Jupiter has it even done so that a group of asteroids is on his own orbit in front of him and another group behind him. This both groups are called trojans. Asteroids have got many different colors, because they consist of different minerals and sometimes they have got water, too. They have got a longish form. Because of many impacts of little stone in space asteroids have got many little craters.



Jupiter is a gas planet with the least distance to the Sun and he is also the biggiest planet in our solar system. Like all other gas giants he is much bigger than the terrestial planets. The core has got a diameter of 30,000 kilometres and consists of a mixture of iron and silicates and a little bit of water ice, methane ice and ammonia ice. Because of the high pressure this material are in a metallical form. The temperature of the core is about 20,000 to 30,000 degrees. The next layer is the outer core which is 30,000 kilometres big and it consists of hydrogen. Because of the high pressure the hydrogen there is in a metallical form. Around the core there is a layer of hydrogen which is 25,000 kilometres big. The atmosphere of Jupiter, the last layer, is 1,000 kilometres big. The atmosphere is quite interesting, because there is a big red spot. Astronoms sees him since 340 years with the help of telescops. It is maybe a storm. The size changes, but we can say that his length is about 26,200 kilometres and this width is about 13,800 kilometres. On Jupiter there are winds about 400 kilometres per hour. In this atmosphere we can find clouds of hydrogen and other unknown materials. All this has been discovered by Voyager 1 and 2. Jupiter like other gas planets has got rings, but im comparision with the rings of Saturn they are small. Jupiter emits radio waves and he has got a big magnetic field, which catchs the particles from the and so on Jupiter there are polar lights like on Earth.

Data to Jupiter
diameter at the equator 142,984 km
mass 1.9 * 1024 t
density 1.33 g/cm3
day (rotational period) 9.84 hours
mean distance to the Sun 778,330,000 km
year (period) 11.86 years
orbital velocity 47,010 km/h
inclination of axis 3.12 degrees
maximum surface temperature -118 degrees
minimum surface temperatur -129 degrees
moons 39



Saturn is a little is less than Jupiter, but the structure is very similar. he is also a gas giant and has got the biggeist und most beautiful rings of our solar system. The core of Saturn has got a diameter of 25,000 kilometres und it consists of silicates, minerals and different types of ice. The core temperature is 14,000 degrees. Around the core there is a layer of metallical hydrogen which is 11,460 kilometres big. The next layer is 4,200 kilometres big and consists of helium. The last layer is 29,000 kilometres big and it consists of hydrogen and a little bit of helium. Around Saturn there is a cloud shell and over this cloud shell there are more clouds of ammonia. The speed of the wind on Saturn is about 1,700 kilometres per hour. The density of Saturn is 0.69 g/cm3 and it is so little that theoretical Saturn would swim in water. Like Jupiter Saturn also emits radio waves and he has got a big magnetic field and so on Saturn there are polar lights, too. Saturn was searched by Voyager 1 and 2. The rings of Saturn consists of rocks and ice particles, which circle round Saturn. Otherwise they would fall onto Saturn. The main rings are called A, B, C and D. This rings are only one kilometre big, so when we look on the front of Saturn we could not see them. Every 14 to 15 years they seem to disappear. The rings were discovered by Galileo Galilei in 1610 and a few years later he was very astonished, because he coulnd not see them.

Data to Saturn
diameter at the equator 120,536 km
mass 5.688 * 1023 t
density 0.69 g/cm3
day (rotational period) 10.23 hours
mean distance to the Sun 1,426,980,000 km
year (period) 29.46 years
orbital velocity 34,700 km/h
inclination fo axis 26.73 degrees
maximum surface temperature -179 degrees
minimum surface temperature -184 degrees
moons 30



Uranus has got a core which has got a diameter of 14,500 kilometres and which consists of iron and silicates. The core temperature is 7,000 degrees. Around the core there is a 10,000 kilometres big coat which consists of water ice, ammonia and methane. The last layer is the atmosphere which is 9,000 kilometres big and it consists of hydrogen, helium and methane. Uranus was searched by the space prob Voyager 2. He has got rings and a magnetic field.

Data to Uranus
diameter at the equator 51,118 km
mass 8.686 * 1022 t
density 1.29 g/cm3
day (otational period) 17.9 hours
mean distance to the Sun 2,870,990,000 km
year (period) 84.01 years
orbital velociy 24,510 km/h
inclination of axis 97.86 degrees
maximum surface temperature -208 degrees
minimum surface temperature -212 degrees
moons 20



Neptune has got a core of iron and silicates. The coat is an ionic ocean of water and ammonia. The atmosphere consists of hydrogen, helium and ammonia. The existence of Neptun was first only calculated, because the scientists searched a solution for Uranus' irregural orbit. Neptun was searched by the space prob Voyager 2 and it has got probably a magnetical field which weaker than the magnetical fields of the three other gas giants. Neptune has got a beautiful blue cloud shell and a big dark spot. Over this cloud shell there single white clouds of methane. Neptune has got rings.

Data to Neptune
diameter at the equator 49,528 km
mass 1.024 * 1023 t
density 1.64 g/cm3
day (rotational period) 19.2 hours
mean distance to the Sun 4,497,070,000 km
year (period) 164.79 years
orbital velocity 19,550 km/h
inclination of axis 29.6 degrees
maximum surface temperature -219 degrees
minimum surface temperature -221 degrees
moons 8



Pluto consists of a rock core, an ice coat and a crust of methane ice, water ice and ammonia. he is a terrestial planet. Scientists have searched another planet, because after the discovery of Neptune they could not explain the irregular orbit of Uranus and Neptune has got also an irregural orbit and this planet was Pluto. Even today scientists cannot explain why the orbits of Uranus and Neptune are irregular. Pluto cannot be the reason, because his gravity is to little. The orbit of Pluto is an ellipse which crosses twice the orbit of Neptune, but this two planets cannot collide, because the orbit of Pluto has got an inclination of 17 degrees to the other planets. Because of these reasons and because of the size of Pluto we think that Pluto was a very big asteroid. But if it is so then it is very astonishing that Pluto has got a moon. This moon is called Charon.

Data to Pluto
diameter at the equator 2,300 km
mass 1.27 * 1019 t
density 2.03 g/cm3
day (rotational period) 6.38 days
mean distance to the Sun 5,913,520,000 km
year (period) 248.54 years
orbital velocity 17,060 km/h
inclination of axis 122.46 degrees
maximum surface temperature -223 degrees
minimum surface temperature -234 degrees
moons 1

Chapter 6: Life

The base for life

the base for life on Earth is the chemical element carbon. It can form very long chains and also circularly molecules. It likes to connect with hydrogen and so hydrocarbon are formed. hydrocarbon are a very important part of chemistry. The most simple satisfied hydrocarbon is methane (CH4), which is also known as natural gas. Carbon also connects with other elements like nitrogen and oxygen. The molecules which form the DNA (desoxyribonucleicacid) consists of carbon, hydrogen, nitrogen, oxygen and phosphorus. These molecules are called adenine, thymine, cytosine and guanine. Later I will also describe the DNA. The range of carbon compounds where life is possible is between the melting-point and the boiling-point of water, because water is very important for life on carbon base. There are also other elements which might be a good base for life: silicon, germanium, sulfur, selenium. Scientists think that this elements could make life at higher temperature possible, but there are not so much possible connections like with carbon.

The formation of life

Today we think that life was formed since 3,800,000,000 years in the water. This organisms were single-celled organisms without a cell core. It is possible that organic compounds came with a meteorid to Earth. In the core of a meteorid organic compounds can be protected from short-wave radiation, that mean from ultraviolet radiation, X-ray, gamma radiation and cosmic radiation from the universe. These types of radiation are radioactive. If you are interested in radioactivy look at the homepage of nuclear physics. In the first atmosphere when life was formed, oxygen atoms formed molecules with other elements. The oxygen which is important for our life is O2. This oxygen consists of two atoms which are connected and so they form an oxygen molecule. 15 kilometres over the surface of Earth there is the oxygen molecule O3. It is also known as ozone.

The DNA (desoxyribonucleicacid)

The DNA is in the cell core of every cell. The DNA contains all heiress formations and when she is inactive we can find her in form of chromosoms. Human beings have got 23 chromosom pairs, but one chromosom pair is the sex chromsom pair. The DNA is a double rope and consists of four molecules: adenine, thymine, cytosine and guanine. There are many of every of these molecules in the DNA. The DNA of human beings consits of 3,000,000,000 building blocks. The molecules are specified with their initial letters. These molecules are on both ropes. A and T can connect and also G and C. These bridges consists of hydrogen. A part of the DNA which is responsible for a feature or a function of the organism is called gene. To form proteins the DNA is copied and this copy is called RNA (ribonucleicacid). To make a copy like that a part of the DNA must spread. The RNA consists of only one rope and so she can make proteins which consists of three molecules, of the DNA. If the RNA would be a double rope she would be closed and so she could not form proteins. Some parts of the DNA are unused today, but maybe they were important during the evolution. You should not associate any bad things with mutations, because the adaptation of human beings to their enviroment is a mutation, too. Radioactivity is very dangerous for the DNA. Radioactivity cuts off parts of the DNA and so it can come to mutations. When the doses is little the DNA can repair herself, but if it is to high then a repair is impossible. The consequence are degenerates cells which begin to split and we have got cancer. An example for adaptation are the people in Kerela in India. In this region are monazit sands with much thorium which is radioactive. The doses there is 48 times as high as in other parts of the world. But there are not more people who have got cancer than in other parts of the world, because throught many generations their DNA has got a better protection. They have adapt themselves to their enviroment. If you want to know more about radioactivity look at the homepage of nuclear physics. Today the whole DNA is decoded and this helps the science to defeat different illnesses. Maybe one day it will be possible to build a complete human being of death matter. But here we must ask ourself if human beings have got a soul. When it is so it would not be possible to create a human being of death matter. I discuss this problem on the philosophy homepage.


Chapter 7: The end of the universe

Today two possibilities are known how the universe can die. When the density of the universe will stay under a certain valence the universe will expand forever. It is also possible that after a certain time the protons will decay into lighter particles. Before this can happen the galaxies will go farer and farer from each other. The stars in the galaxies will have less mass, because after the death of a star not his whole matter is used to form a new star. There will be more and more residues like white dwarfs, neutron star and black holes. The last active stars will be the red dwarf and the red giants. In the end there will be only residues and nothing will illuminate. The temperature of the universe will be less than today. When we think about the whole visible mass a scenery like that is possible. But scientists have discovered that in the universe there is much dark matter in form of black holes and brown dwarfs. When a certain density will be reached in the universe it would not expand forever, but it will collapse. All galaxies and also the black holes will come closer and closer then and in the end they will fuse together. All the matter will form a singularity, a place where our physical laws do not exist. This singularity which is now our whole universe will be as big as the object of what our universe was formed. It is possible that after the death of our universe another universe will be formed of this object. So the circle of death and reincarnation of the universe is closed. But all this might happen in a few trillion years or even more.

Please put in your weight on Earth: kg

Mercury: kg
Venus: kg
Mars: kg
Jupiter: kg
Saturn: kg
Uranus: kg
Neptune: kg
Pluto: kg
Sun: kg
Neutron star with 1.4 sun masses (not rotating): Mt
White dwarf with 1 sun mass: t

On the Download page you can find the C++-version of this program.

Author and Webmaster: Lukas Czarnecki

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Last Update: 19.05.2002