The universe - stars, planets, comets, the moon
Solar System and Universe: A very interesting topic, about planets, stars, black holes, comets and more. Useful for anyone who wants to gain basic knowledge about the solar system and the universe or learn new things about it.
Contents:
- Orientation on the universe and space research
- Influence of the sun and moon
- Movement of the sun, earth and moon
- Movement of the sun, earth and moon
- Stars and galaxies
- The search for extraterrestrial life
- Orientation on the universe and space research
1. Orientation on the universe and space research
A sun is a star that is not different from any other star. Nuclear fusion takes place in the interior of the sun. Due to the distance of the sun from the earth, sunlight takes 8 minutes to arrive on earth. The light from the moon reaches the Earth within 1.3 seconds.
The stars we see are a small part of the Milky Way. Stars are 4.3 light years or more away from us. The Milky Way is one of the galaxies of the universe. Another example of a galaxy is Andromeda, which is about 2.4 million light years away.
There are 8 planets, 5 of which you can see from here: Venus, Mercury, Mars, Jupiter and Saturn. All planets move around the sun. Comets come from a spherical cloud and often consist of ice. After decades,
the comet may pass by Earth again.
A meteor is a dust particle that enters the Earth's atmosphere at great speed. Such a dust particle often burns up in the atmosphere.
Satellites revolve around the Earth in a few hours, larger satellites such as the ISS can be clearly seen from Earth.
Patterns were discovered in the universe a long time ago, but it was only after the
invention of the telescope that it was discovered that the Earth was not the center of the universe was, and with the Hubble Space Telescope we learned much more about most stars.
You can see all kinds of objects from Earth. Often something looks like a small dot, but it can actually be an entire galaxy.
Research in space is very expensive. The reasons why we conduct research in space include finding answers to issues such as the origins of the Earth, life on Earth, life in other places in the universe, the origins of the universe and galaxies.
2. Influence of the sun and moon
All living organisms depend on the energy of the sun, plants also need sunlight to produce substances such as glucose and oxygen.
It is not the sun that moves across the sky, but the earth that rotates. The sun was and still is used to tell time. The diurnal arc of the sun is the path of the sun across the sky, which is different every day. The day arches are also different in different places.
In winter the sun is lower in the sky, so the sun shines for less time. This is because the Earth's axis is tilted relative to the Sun, at an angle of 23.5 degrees. At the beginning of the first half of the year it is winter in the Northern Hemisphere, and summer in the Southern Hemisphere, the second half of the year it is exactly the other way around. This is because the earth revolves around the sun, so that after six months the earth is on the other side of the sun. When the sun is higher in the sky (from the Earth), it is warmer in that location. This is because the sunlight comes straight from above, so the light energy is distributed over a smaller surface area.
A year is 365 days, during which time the earth revolves around the sun once. It takes a moon 29.5 days to revolve around the Earth. A lunar year is 354 days. Every 15 degrees is a time zone, and one hour is added or subtracted from the time. How many hours are added or deducted depends on the location opposite the town from Greenwich. Below is the world, divided into time zones:
The earth, sun and moon attract each other due to gravity. The moon draws the water on Earth towards itself. This creates a high tide. The earth rotates slowly, causing the moon to continuously draw in a different piece of water. If the water is not attracted to the moon, it will be low tide. The effect of the moon's mass is that a kind of water mountains form in the earth on the side of the moon and on the other side of the earth. It is high tide on that side.
3. Movement of the sun, earth and moon
There are four movements of the earth, the movement of the earth on its axis (23.93 hours), the moon revolving around the earth (29.5 days) and the earth revolving around the sun (365.256 days) the moon it rotates on its axis, but the same side always faces the earth.
A solar eclipse and a lunar eclipse can occur on Earth. A lunar eclipse occurs when the Earth is between the sun and the moon, so light cannot reach the moon. A solar eclipse occurs when the moon is between the sun and the Earth, preventing light from reaching the Earth. Below is a clear picture:
4. Movement of the sun, earth and moon
The Greeks could already distinguish planets from stars, because the planets do not move with the stars. Galileo Galilei was the first to see the moons of Jupiter, he noticed that not all four points of light were always visible. In Galileo's time, people thought that all heavenly bodies moved around the earth and that the earth was the only one stationary. The fuller Venus became, the further away it became, this is because Venus is much further from Earth when it is full. So he was actually the first to show that the earth was not central to the universe, which clashed with the views of the church. It was later discovered that there were many more moons. The 4 moons of Jupiter are called Io (consists largely of stone and iron), Europa (consists largely of stone and iron), Ganymede (consists largely of water ice) and Callisto (consists largely of water ice).
Inner planets are planets that are closer to the sun than the Earth, which is only Venus and Mercury.
Outer planets are planets that are further away from the sun than the Earth (the rest!)
Rock planets are Mercury, Venus, Earth and Mars.
Gas planets are the rest of the planets
Pluto is a dwarf planet and is no longer one of the planets nowadays. It is thought to be a boulder from the Kuiper Belt.
Meteors burn up in the Earth's atmosphere because the Earth crosses a path of small dust particles, which then impact the Earth's atmosphere.
A meteorid looks like a meteorite, but is larger. This can fall on Earth, if that happens it is called a meteorite. It
is not yet certain where comets come from, but probably from the Oort cloud. Comets can be seen from Earth for extended periods of time, such as Comet Hale-Bopp, which was visible for 18 months, even during the day.
5. Stars and galaxies
A star consists of a ball of hydrogen gas with a very large mass. Nuclear reactions take place in the center of the star, this happens because hydrogen fuses into helium. A star radiates that energy as light and other types of radiation. Stars can also have other colors, Annie Jump was the first to make a classification based on color, shown below:
- Hot, blue or white stars
- type O (blue) – temperature 50,000 Kelvin (K)
- type B (blue) – temperature 33,000 K
- type A (white) – temperature 11,000 K
- Yellow or orange, sun-like stars
- type F (white) – temperature 8000 K
- type G (yellow) – temperature 6000 K
- type K (orange) – temperature 5000 K
- Cool, red stars
- type M (red) – temperature 3600 K
You can say that the higher the temperature, the younger the star. When a star is 'up', they swell and then contract and extinguish. If the star had a very large mass, a black hole could be formed.
Also applies: The whiter the color, the higher the temperature.
A star usually forms when dark molecular nebulae clump together due to gravity. More and more is attracted, creating a swirling ball of gas. When the gas ball contracts, its temperature rises, causing nuclear fusion to take place.
Lord Rosse discovered that some 'dots' are entire solar systems, this was a major discovery, as the universe turned out to be much larger than previously thought. Scientists estimate that there are 300 billion galaxies in existence. Because the distance between stars is so enormous, light years are used. A light year is the distance light travels in one year, which is about 10 trillion kilometers. The Milky Way can be seen as a white band from Earth.
Edwin Hubble was the first to determine the distances of galaxies from Earth. He used the brightness of the stars for this. For example, he used this to determine the distance of the Andromeda Galaxy, 2.2 million light years. Edwin Hubble showed that the redshift is greater the further away the object is. So the further galaxies are from us, the faster they move away from us. This led to the big bang theory.
Other objects are also found, but they can no longer be found with the light telescopes. Radiations such as infrared and X-rays are used for this.
6. The search for extraterrestrial life
Certain conditions are necessary for life.
Conditions that affect extraterrestrial life:
- Temperature
- Liquid water
- Atmosphere
- Busy
- Elements
- Substances
- Energy
- Volcanism
- Thunder and lightning
When researching extraterrestrial life, a distinction is made between intelligent life and micro-organisms. Intelligent extraterrestrial life is a civilized being, which would be so developed that they could travel through space. There are many theories about how aliens will take over Earth and the planets they live on. There is a greater chance that micro-organisms exist. For example, single-celled ones are microorganisms.