ciencias

The solar system

The sun and all the celestial bodies that orbit it from the solar system. The solar system contains nine planets and their satellites.
Our solar system is part of the Milky Way galaxy.
The sun:
The sun is a star; it gives off heat and light. It appears yellow and is made up of gases. The sun is very big. It is bigger than all the planets in the solar system put together. It is more than a million times bigger than earth.
However, the sun is not particularly large for a star. It looks bigger than other stars because it is nearer to earth.
Earth receives heat and light from the sun. Earth is exactly the right distance from the sun for life to be possible here. If earth were nearer to the sun, the heat would burn us. If earth were father away, the cold would make life here impossible.
Planets and satellites:
Nine planets revolve around the sun. The path these planets take around the sun is called their orbit.
Planets:
*mercury: is much smaller than earth. Mercury has the shortest orbit around the sun
*Venus: is similar in size to earth, it is the brightest planet. Its surface has the highest temperatures.
Earth: is the only planet in the solar system to here there is life.
Mars: is an intense red color, it is full of craters and volcanoes. Some of these volcanoes are bigger than any mountain on earth
Jupiter: is the biggest planet I the solar system. T has a red pot on its surface.
Saturn: is surrounded by thousands of rings are made up of millions of small particles.
Uranus: Have characteristics blue-green color.
Neptune: is one on farthest planets from the sun, it is blue
Pluto: is the smallest planet. It is the farthest planet from the sun which is why it is also the coldest planet.
All the planets in the solar system except mercury and Venus have satellites the moo is earth’s only satellite.
The movements of earth

Earth’s constantly moving like all the planets in the solar system earth orbits the sun. It also rotates constantly.
-rotation: earth rotates on a imaginary axis.This axis crosses earth from the north pole to the south pole.
earth take 24 hours to make rotation.This are the 24 hours in a day. rotation produces the sequence of day and night.
revolution: earth also orbits the sun. earth takes about 365 days to complete one revolution around the sun.these are the 365 in a year.every fourth years has an extra day. these are leap years

The earth and the universe
The universe: all the bodies sky between the spaces them form the universe. The universe is very old. It began 15 bition years ago after a large explosion distances are huge in the universe.
For example:
The light emitted by the star nearest our solar system takes for years to reach our planet.
Celestial bodies:
There are many different bodies in the sky. These incluse stars, light the sun, planet, light, earth, and satellites, light the moon they are old called celestial bodies. They are two types of celestial bodies. Stars all luminous celestial bodies this means.
-they emit their own light
-they look likes small pants of lights.
-they are infact very big. Stars are different colors:
The hottest are blue and coolest are yellow and red.
*nonluminous celestial bodies
Planets, satellites, and comets are nonluminous celestial bodies this means they to not emit their own light.
-planets: orbit start
-satellites: orbit planets
-the Lune: is the earth’s only satellite
-comets: comets are small celestial bodies that orbit the sun. They do not emit their own light. They are made of ice and dust; these materials became luminous in the atmosphere and form a long tail. Comets are visible from earth periodically.For example: the hale Bopp comet can be seen every to thousand 2,364 years.ConstellationsWhen we look up at the stars from earth, they are appear to be in groups of stars are cold constellations.GalaxiesCelestial bodies are not isolated. They form groups’ cold galaxies. There are many millions of galaxies in the universe. Each galaxy is made up of millions of celestial bodies. Earth is in the Milky Way galaxy. Galaxies have different shapes.

Hormones are substances that control very important process in the human body. For example, hormones are involved in growth, puberty, and breast-feeding. Hormones are produced in organs called endocrine organs. The hormones enter the bloodstream and reach other organs, where the have a specific effect.
The pituitary gland is an endocrine organ it is located in the brain. The thyroid is also an endocrine organ. it is located inside the neck, in front of the larynx.

If the spectrum of a star is studied with high-resolution methods can be seen many dark lines at certain wavelengths. These lines are due to light absorption in the deeper layers of atoms of the upper, cooler. The atoms in the star are identified by comparing the stellar absorption lines with those produced in the laboratory by gas known; you can also calculate the temperature and pressure of the atmosphere and the relative abundance of chemical elements. See Fraunhofer lines. Most of the stars are at a stage of its life known as the "main sequence", at this stage, the temperature and luminosity increase with mass. Some stars are brighter and therefore larger than the sequence of the same temperature: the so-called red giant stars. Many stars are weaker and therefore smaller than the sequence of the same temperature, such as white dwarfs (1% of the diameter of the Sun) and neutron stars (0.001% of the diameter of the Sun). Theoretical models of stellar interiors have been calculated based on the theory of balance between the force of gravity, contributing to the collapse of the star, and the pressure of reheated gas, which tend to expand. High temperatures also drive a stellar heat flow from inside to outside the star. For the star is in equilibrium, this heat loss must be offset by the energy released in nuclear reactions internal. As above the various nuclear fuels, the star evolves slowly, and the core shrinks to increasing densities.