lunes, 9 de noviembre de 2009







DIGESTIVE SYSTEM
RESPIRATORY SYSTEM
CIRCULATORY SYSTEM
EXCRETORY SYSTEM

VERTEBRATES AND INVERTEBRATES

martes 27 de octubre de 2009

    THE PROCESS OF NUTRITION


the animal kingdom is so huge and varied that it is very difficult to summarise how the different processes are carried out.


  • All animals need take food from their environment, all animals need to process the food in order to extract the nutrition elements. The processing of food takes place in the digestive system. Animal digestive system iis made up of a length of tube whish the food runs throught and in whish the food is transformed. Birds and mammals have a more complex digestive system than invertebrates whose system is much more simple or even not-exist, as in the case of sponges.


  • Animals also need to take oxygen from their environment, animals have a variety of differents respirator organs fish and many aquatic invertebretes have gills, insects have small tubes called trachea, and amphibeans, reptiles and mammals have lungs.



  • all animals need a system for transporting the substances they need to survive to the cells this is called circulatory sistem its more conplicate in the vertebretes than that of invertebrates.
  • finally all animals have an excretory system whish clean the blood and eliminates waste products.


VERTEBRATES AND INVERTEBRATES


INVERTEBRATES

Poriferan: are sea sponges


Coelenterates: are jelly fish,
corals and sea anemones.
Their bodies are soft and
almost see-through.

Arthropods: are insects,
spiders, crabs and centipedes.
They have a shell, legs and
antennae. Some of them also
have wings.

Molluscs: include snails, clams,
octopus and squid. They have
soft bodies but most of them
also have a shell.

Equinoderms: include sea urchins
and starfish. They have spines
and layers whish form a hard shell.


VERTEBRATES

fish: are acuatic, vertebrates
with scales, fins and tube.like
bodies. The are oviparous
and they breathe through.

Amphibians: include frogs
and salamanders. They are
oviparus. During their early stage
of growth they are aquatic
and their breathe through
gills. The adult animal
breathe using lungs and are
ussualy land creatures.

Reptiles: include snakes,
lizards, tortoises and
crocodiles. Most of htem
are land creatures. They
have scales, they are oviparous
and they breathe using lungs.

Bird: are land creatures.
Their bodies are covered in feathers.
They fly using wings. They are
oviparous and they breathe using lungs.

Mammals: are land creatures although some of them live in the water. Most of the have hair. They are viviparous and they breathe using lungs.

divercity of plants

22 September/ 09


THE DIVERSITY OF PLANTS

The plant kingdom is the second largest kingdom ( has the most species) after the animal kingdom. There are around 200,000 known species of plant.

We have seen a non-scientific classification of plants according to their shape. In order to classify them scientifically we have to use the criteria.

Plants are either vascular or non-vascular. This means that they either have or don't have a tube like structure which transports water, nutrients and mineral salts up the steams.
Some plants produce flowers and some do not.
some plants produce fruit and others do not.
Using these three criteria we can divide the plant kingdom into four large groups:


1.Bryophytes or mosses: commonly called mosses and liverworts, they are the smallest and simplest of all the plants. They have no fruit and are non-vascular. They depend on the presence of water of their survival and life in damp places.
2.Pterydophyta: this is a group of ferns. They are medium-sized vascular plants but they have no flower or fruit. They have large leaves are divided up into different sections. They also live and damp places.
3.Gymnosperms: this plants are vascular and they have flowers but not fruit. Most of them are threes or bushes like the pine tree and juniper bush or cypress. The largest tress in the world, the sequoias, belong to this group.
4.Angiosperms: these-plants are vascular, they have flower and fruit. This group of plants is the most varied because it includes grasses, bushes and trees. Some examples are, poppies, roses, rock-rose, thyme, holm cak, chestnut etc.

NUTRITION IN PLANT

FOOD FOR PLANTS

plants are producers which means that they produce their own food. In order to do this they need to absorb substances from the soil and the air and to transform them. This process has the following steps

1.plants absorb water and mineral salts from the soil plants need to absorb to their root . Various different mineral salts are dissolve in the water. The mixture of mineral salt and water which is up sort, by the plant is noun us raw sap.
2.The steamtransport the raw sap of the leaves, the rous sap moves up wards from the roots to the steam. After these if caries on up words through the vanes in ther steen, until it riches the leaves.
3.The raw up is transformed in the leabes, the fundamental proces of nutrition takes places in the leaves. This proces is called photosintesis.
4.The elaborated sap is distributed throughtout the plant finaly the nutrients containet in the elaborated sap are distributed throughtout the plant. It richers all the cells throught the vessels.



PLANTS RESPIRATION

plants breathe just as animals do. Their leaves takes oxygen from the airand release carbon dioxyde . Howeber, during the proces of photosintesis they take in carbon dioxide and realice oxygen. This proces of respiration involbes the taking and the relasing of glases bat in the reverse order as happends during nutrition. During the proces of nutrition the plant takes in carbon dioxide and releases oxygen.

During the day time the two proceses, respiration and nutririon are simultaneous. Howeber at night they are not.
.
During the day time plants breathe and carry out the proces of photosisntesis at night plants do not photosintesi but they do beathe

SEAS AND OCEANS

SEas AND OCEAN



the water in the seas and oceans covers almost three cuarters of the earthest surface earth the averal depth of the oceans is three thousand seven hundred
ninty five metres.

THE SALINITY OF SEA WATER


sea water is different from the continental fresh water in sow far as it has a wite content of south solution. the most common sauth in the sea water is
solt you lorate common south. there are also matter cuantities of lorate and others salt content of sea water ofr sea water is could it salinity and it is measere
in grams of soath lost a kg of water, the averech salinity of the water inthe oceans is 35 gramss, pear kg of water.*

in one water seas, were the water evaporate more the risajair level of salinity pearrit, in the red sea for example the salinity 41 grams pear kg of water*
in the very cold seas level of salinity is mach lower for example, in the valtic sea the salinity is only tell wgrams of sauth 10 kg of water, this level of salinity
is similar to some rivers and laker saltiest sea of all, is the dead sea whish has a salinity of 360 grams of salt pear kg of water,
haw ever the dead sea is not realy asi, it is a lake.

the constant movement of water


whe we amalise the movement of water we can see trhree differents site of movements:

1 the waves: are surface and dulations of the sea water and they are do to the action of the wind.

2 the tides: are increces and dicreaces in the level of the sea whish happend to a wrater or laced the wree or true the day.

3 the sea currents: are movements of hiuch mases of water from one point in the planet two anoter. there are one and could currents depending all the point of sorrilling of the movement and the areas
that the currents move thrue.

tarea: cuales son las corrientes marinas, y poner foto

PLANTS

plants

what is a plant?

its a living being

the plant kingdom in made up of organims with the following common characterisc:

they have eucaryotic cells organized into tissues. each tissue has a different funtion: growth, protection, etc. in turn the

fissues are grouped together to make organs such as leaves.

they are producers. they do not need to take in food like animals because they produce their own food.

what do all plants have in common ?

all plants have roots, steams and leaves.

they are green due to substance called chlorophy

plants cannot move themselves from one place to another but they do move.

homework: investigate and write the characteristics of:


grasses: have soft, flexible, green steems sam it samples of glases are:

wheat, nettles, violets, and poppis. Many plants in this category are very small bat others like the banana plants measure of the 2 meters and look like threes

bushes: are plants with a heart, woudy steem called a trunk. Bushes have a short trunk anf the branches grow outwards from the base, very close to the ground. Some bushes are very small like thime and others can grow up 2 m tall like box.

trees: have a much longer trunk and their ranches grow higher at the plant up the trunk. Some examples of threes are:

oack

holk

hold and pain.

PLANT REPRODUCTION

Plant reproduction

plant can reproduce in two different ways:

1)asexual reproduction: only one individual is involved in creating a new plant from its own parts. When we take a cutting off a geranium and replant it we are, in fact, aiding the plant in a asexual reproducction.
2)Sexual reproducction: two individuals are involved. The uniun of special cells from each of them produces a new plant. This is what happens when plants are reproduce throught flowers. Whithing these two broad groups there are many arieties. Some of the ways that angiosperms reproduce.
3)Flowers: the reprductive organims of angiosperms and gymnosperms are the flowers have two parts:
4)the reproductive: parts of a flower are the stamen and stigma
5)the productive: parts of flower are the petals whish make up corolla and the sepals whish up calyx
6)the ovules: are inside the stigma. When the ovules come into contact with the pollen produced in the stament they turn into seed. The flowers turn into fruit.
7)The reproducction proces:
1) pollination: pollen is transported from one flower to another on the wind or by insects like bees and buterflies. This transportation is pollination.
2) the fertilisation of the ovules: when a grain of pollen reaches the ovules. This is how the ovules are ferlilised.
3) the forming of fruit: after this the flower changes. The corolla and the calyx dry up and the stigma grows and changes until it becames the fruit the seeds. Whish are formed from the ovules are inside the fruit.
4) the germination of seeds. The seeds fall on the ground and, in a very short time, they germinate. The seeds open, a samall root comes out and tiny leaves begin to grow. A new plants graws the seeds.

miércoles, 12 de agosto de 2009

The water cycle.

The water cycle
Water moves from one part of the planet to another. it falls from the atmosphere down to the earth, rivers and seas.
It evaporates from the earth, rivers and lakes and goes back into the atmosphere.
This continual movement of water from one place to another is know as the water cycle. Living being also interve in the water cycle.
Example:
Trees more huge quantities of water. Theyabsorb water through their roots and then lose it it again through their leaves.
Why does water move?
  • The movement of water from the rivers to the seas is due to the inclination the land. The movement of water from glaciers and the sow from from the mountains to the rivers is due to melting.
  • The movement of from seas, and lakes to the atmosphere is due to evaporation.
  • Water vapour cools in the atmosphere and forms drops of water.This is condensation.

Water is not evenly spread out
este es el ciclo del agua, el agua cae y nuevamente sube al cielo pero evaporada en los dias de calor.

martes, 11 de agosto de 2009

The propierties of water

Water properties

Before we begin looking at the properties of water, maybe you'd like to take our True/False quiz about water properties. Some of the answers may surprise you.

What are the physical and chemical properties of water that make it so unique and necessary for living things? When you look at water, taste and smell it - well, what could be more boring? Pure water is virtually colorless and has no taste or smell. But the hidden qualities of water make it a most interesting subject.

the water have 3 states

solid: for example, ice

Water pollution: is the contamination of water bodies such as lakes, rivers, oceans, and groundwater. All water pollution affects organisms and plants that live in these water bodies and in almost all cases the effect is damaging either to individual species and populations but also to the natural biological communitis. It occurs when pollutans are discharged directly or indirectly into water bodies. without adequate treatment to remove harmful constituents.


Industrial waste is a type of waste produced by industrial activity, such as that of factories, mills and mines. It has existed since the outset of the industrial revolution.

Much industrial waste is neither hazardous nor toxic, such as waste fiber produced by agriculture and logging.

Toxic waste and chemical waste are two designations of industrial waste.

Sewage treatment can be used to clean water tainted with industrial waste.


OIL SLICKS

Oil slicks float on oceans and seas, covering them in a thick film of crude or refined petroleum oil. When freight ships carrying tens of thousands of tons of fuel crash, malfunction, or encounter harsh weather, they spill enormous amounts of oil into the water. Since oil and water don't mix, the oil spreads out into a layer that hovers, as one mass, on top of the ocean.

miércoles, 5 de agosto de 2009

martes 4 de agosto de 2009
how aquatic creatures adapt
many organisms live in a water medium. these creatures are well-adapted for moving and breathing in water.

- aquatic plants and weeds have flexible steams which do not break when they are moved by the current. they don need strong stems like plants on land because the water support them.

-aquatic animals usually have a streamlined shape like, for example a fish so that they can overcome the resistance of water. their extremities are usually wide like oars.

BREATHING IN WATER

aquatic plants and animals obtain their oxygen from the oxygen dissolved in water.

-aquatic plants breathe thought their leaves like plants like plants on land.

-aquatic animals have different organs for obtain oxygen from water. fish for example, have organs called gills which they use for breathing. gills are made up of small filaments which take in oxygen and expel carbon dioxide. this system.

martes, 21 de julio de 2009

water

THE WATER PLANET



what is water?


water is a colpourness, odourless and tasteless liquid.
this definition refers to pure water. it is in fact extremely
difficult to find pure water in our surroundings. an example
what we usually means by water es the in the rivers and
seas orv tap water and this water is a mixture of various substances.

the predominant substancee in these mixtures is purewater but pthers substances
are suspended in solutions, usually mineral salts. the great variety of
salts that can be suspended in water means that there are different
types of water. sea water has more salt content than river water
tap water alse has salts and other substances which are added to makes
it safe for drinking.

miércoles, 10 de junio de 2009

Water

WATER

The lasic definition of water is as follows:
Water is a colorless, odourless and tasteless liquid.
This refers to pure water.
What we usually mean by water is the water in the rivers and seas or top water is the water in the rivers and seas or tap water and this water is a mixure of varius subtances.
The predominant subtance in these mixure is pure water but other subtances are suspended in the solution, usually mineral salts. The great variety of salts that can be suspended in water means that there are different types of water. Sea water has more salt content than river water. Top water also has  salts and other subtances which are added to make it save for drinking.

The water molecule:
Water is made up of molecule consisting of atoms fro two elements hydrogen and oxygen. Each molecule is made up of one atom of oxygen and two atoms of hydrogen.

Notice that since water is in a liquid state the molecules are scattered about and can move relatively freely amongst themselves

miércoles, 15 de abril de 2009

otation: the rotation produce the change of tha day to night
inclination and revolution: produce the seasons

The Moon

is a satellite of this earth

Movements of the Moon

moves around of the earth and it takes abaut one month to produce this movement

the other side of the Moon is called the darcksite

Luna Phases






Lunar Eclipses


Lunar eclipse

From Wikipedia, the free encyclopedia

Schematic diagram of the shadow cast by the Earth. Within the central umbra shadow, the Moon is totally shielded from direct illumination by the Sun. In contrast, within the penumbra shadow, only a portion of the sunlight is blocked.
As seen by an observer on Earth on the imaginarycelestial sphere, the Moon crosses the ecliptic every orbit at positions called nodes twice every month. When the full moon occurs in the same position at the node, a lunar eclipse can occur. These two nodes allow two to five eclipses per year, parted by approximately six months. (Note: Not drawn to scale. The Sun is much larger and farther away than the Moon.)
As viewed from Earth, the Earth's shadow can be imagined as two concentric circles. As the diagram illustrates, the type of lunar eclipse is defined by the path taken by the Moon as it passes through Earth's shadow. If the Moon passes through the outer circle but does not reach the inner circle, it is a penumbral eclipse; if only a portion of the Moon passes through the inner circle, it is a partial eclipse; and if entire Moon passes through the inner circle at some point, it is a total eclipse.

lunar eclipse occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur only when the Sun,Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7, 2009.




Types of lunar eclipses

The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra. Within the umbra, there is no direct solar radiation. However, as a result of the Sun's large angular size, solar illumination is only partially blocked in the outer portion of the Earth's shadow, which is given the name penumbra.

penumbral eclipse occurs when the Moon passes through the Earth's penumbra. The penumbra does not cause any noticeable darkening of the Moon's surface, though some may argue it turns a little yellow. A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth's penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the Moon which is closest to the umbra can appear somewhat darker than the rest of the Moon.

partial lunar eclipse occurs when only a portion of the Moon enters the umbra. When the Moon travels completely into the Earth's umbra, one observes a total lunar eclipse. The Moon's speed through the shadow is about one kilometer per second (2,300 mph), and totality may last up to nearly 107 minutes. Nevertheless, the total time between the Moon's first and last contact with the shadow is much longer, and could last up to 3.8 hours.[1] The relative distance of the Moon from the Earth at the time of an eclipse can affect the eclipse's duration. In particular, when the Moon is near its apogee, the farthest point from the Earth in its orbit, its orbital speed is the slowest. The diameter of the umbra does not decrease much with distance. Thus, a totally-eclipsed Moon occurring near apogee will lengthen the duration of totality.

 Matter
what is matter? every thing that sound rounds as is make for matter, the earth,the rocks,animals,plants,everything,we cut define matter as all that ocupies space and can be weghed, when we are studie matter we use some basic quantities suchas lenght,surface area volume,mass,densit,or temperature.   so that are all using the same units in science we use what is called the internacional sismems in unites (S.A)

martes, 14 de abril de 2009


Jewish calendar


Jewish calendar is a lunisolar calendar used by Jews and the followers of Judaism, now predominantly for religious purposes. It is used to reckon the Jewish New Year and dates for Jewish holidays, and also to determine appropriate public reading ofTorah portionsYahrzeits (dates to commemorate the death of a relative), and daily Psalm reading, among many ceremonial uses. Originally the Hebrew calendar was used by Jews for all daily purposes. During the era of the Roman occupation (1st century BCE), Jews began additionally following the imperial civil calendar for civic matters such as the payment of taxes and dealings with government officials.

The principles of the Hebrew calendar are found in the Torah, which contains several calendar-related commandments, including God's commandment during the Exodus from Egypt to fix the month of Aviv as the first month of the year. The Babylonian exile in the 6th century BCE influenced the calendar, including the adoption of Babylonian names for the months.

martes, 31 de marzo de 2009

The materials of the earth surface
The earth is made up of solid materials predomunant in the litosphere, liquid more usual in the idrosphyre and gaseus predominant in the admosphere
Materials in the admosphere
The admosphere is made up of mostly gaseus materials. There are also solid and liquid materials like the minute drops of water nd ice that make up the clouts. As far as we are concermet the most inportant material in the asmosphere is air. Air is not a gas but a michure of gases, it is made up of 78& nitrogen, 21% oxigent and 1% other gases
materials in the hydrosphere
The hydrosphere is made up almost exclusively of 1 material, water. Most of the water in the hydrosphere is in a liquid state but the solid water, ice and snow, is sow sow consideret to be part of the hydrosphere. There maybe other materials in the water of te hydrosphere. For example sea water is very reach in salts. We can say that sea water is a mitsure of sant a water
Materials in the litoaphere
The litosphere is made up of rocks and mineral. These are solid materials, which can be many diferent types, chapes,sizes and colors. Sand is made up of small particles of rock. Clai is also made up of minute particles of rock mixt whit water.
workshop
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment, into the atmosphere.
EXAMPLES
Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from high temperature combustion.
Carbon monoxide - is a colourless, odourless, non-irritating but very poisonous gas.
Carbon dioxide (CO2) - a greenhouse gas emitted from combustion but is also a gas vital to living organisms. It is a natural gas in the atmosphere.
Where is the earth is more pollutet?
  • Chernobyl, Ukraine
  • Dzerzinsk, Russia
  • Haina, Dominican Republic
  • Kabwe, Zambia
  • La Oroya, Peru
  • Linfen, China
  • Mailuu-Suu, Kyrgyzstan
  • Norilsk, Russia
  • Ranipet, India
  • Rudnaya Pristan, Russia

Because are the most evolution countries of the earth....because they have most enterprices.

miércoles, 25 de marzo de 2009

:

The inside of the earth :
when we study the indide of the earth we find three layers: the crust, the mantle and the nucleus.
The Crust: Is the external layer of the earth. Its thickness varies from 6 to 12 kilometres on the sea beds to around sixteen km in th continental aries where the great mountain ranges are lokedet
The Mantle:is the layer wich goes from the earth´s crust down to a depth of two, 2900 km
The core: Is the inner-mostlayer. It goes from a depth of 2900 km to de earth´s core which is locker about 6378 km from the surface.The earth´s crust and the mantle form the litosphere.

homework: the materials of the earth´s surface.
t materials of the beach,in the litosphere ,atmosphere and the
the earth
the earth thas not have its on lite nider do eny of the other planets.the reason why whi see and iluminated planet when we look at the earth from space is because the earth resest light from the sun whish is the nearest star.
the earth is the therth planet in the solar sistem, whish is a set of celestial bodies be longin to a galaxi could the milkiway. the earth has onli one satelite could the moon.the parts of the earthlithophere hyerosphere
atmospherelithophere:

material of http://en.wikipedia.org/wiki/HydrosphereEarth's lithosphere In the Earth, the lithosphere includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the planet. The lithosphere is underlain by the asthenosphere, the weaker, hotter, and deeper part of the upper mantle. The boundary between the lithosphere and the underlying asthenosphere is defined by a difference in response to stress: the lithosphere remains rigid for long periods of geologic time, where as the asthenosphere is plastic. The lithosphere is fragmented into plate tectonics (shown in the picture), which move independently relative to one another.The concept of the lithosphere as Earth’s strong outer layer was developed by Barrell, who wrote a series of papers introducing the concept (Barrell 1914a-c). The concept was based on the presence of significant gravity anomalies over continental crust, from which he inferred that there must exist a strong upper layer (which he called the lithosphere) above a weaker layer which could flow (which he called the asthenosphere). These ideas were enlarged by Daly (1940), and have been broadly accepted by geologists and geophysicists. Although these ideas about lithosphere and asthenosphere were developed long before plate tectonic theory was articulated in the 1960s, the concepts that strong lithosphere exists and that this rests on weak asthenosphere are essential to that theory.The lithosphere provides a conductive lid atop the convecting mantle; as such, it affects heat transport through the Earth.The division of Earth's outer layers into lithosphere and asthenosphere should not be confused with the chemical subdivision of the outer Earth into mantle, and crust. All crust is in the lithosphere, but lithosphere generally contains more mantle than crust.There are two types of lithosphere:Oceanic lithosphere, which is associated with Oceanic crustContinental lithosphere, which is associated with Continental crusthyerosphere: HydrosphereFrom Wikipedia, the free encyclopediaThe movement of water around, over, and through the Earth is called the water cycle, a key process of the hydrosphere.A hydrosphere (from Greek ύδωρ - hydor, "water" + σφαίρα - sphaira, "sphere") in physical geography describes the combined mass of water found on, under, and over the surface of a planet.Contents [hide]1 Other hydrospheres2 See also3 References4 External links[edit]Other hydrospheresA thick hydrosphere is thought to exist around the Jovian moon Europa. The outer layer of this hydrosphere is almost entirely frozen, but current models predict that there is an ocean up to 100 km in depth underneath the ice. This ocean remains in a liquid form due to tidal flexing of the moon in its orbit around Jupiter.It has been suggested that the Jovian moon Ganymede and the Saturnian moon Enceladus may also possess sub-surface oceans. However the ice covering is expected to be thicker on Jupiter's Ganymede than on Europa.atmosphere: AtmosphereFrom Wikipedia, the free encyclopediaFor other uses, see Atmosphere (disambiguation).View of Jupiter's active atmosphere, including the Great Red Spot.An atmosphere (from Greek ατμός - atmos, "vapor" + σφαίρα - sphaira, "sphere") is a layer of gases that may surround a material body of sufficient mass,[1] by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, but only their outer layer is their atmosphere (see gas giants).The term stellar atmosphere describes the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Relatively low-temperature stars may form compound molecules in their outer atmosphere. Earth's atmosphere, which contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis, also protects living organisms from genetic damage by solar ultraviolet radiation. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

images:

martes, 10 de marzo de 2009




  • Que es un sistema de estrellas binarias?
    desart to stars tha turn around acommon senter point










    cluster stars system

    these are groups of tens, hundreds or thousansof stars










    diferent types of stars, stars have different characterics:
    color:when we luck at the stars though binocules or evenwith the naked eyes we can see different tound and different stars. Some are bluish, readdish, orange, and so on.
    - the sun is a yellow star.

    on the other hand,sirius be of comies majoris a hundred times smaller than the sun
    bear

    brightness
    some stars are brigther than others.sirius is very bright other sars are so faint that we cannot see them with the naked eye, they have been discoverd thanks to the use of telescopes
    light
    some stars emmit more light than others, to stars emitting the same amount of ligth will not be as brigth as each other is they are at different distances from the earth.
    HOMEWORK: hacer una presentacion en power poin en ingles,de los planetas del sistema solar donde diga,



  • masa



  • distancia del sol



  • radio



  • periodo de rotacion



  • periodo de traslacion




Ademas como sta organizado el sistema solar.





galaxi are make up of groups of stars, geses and dust awar galaxi is could the milki way, the nears galaxi to awer own is andromeda whish is more than two million lait years away. this means that when why look a this galaxi whi are seing it as it was more than two millions years ago.dependy or there cheip galaxis can be:








elliptical: is more or less spherical









Añadir imagen










spiral: a flat thisc whith several arms caming aut of the nucleous of spiral

The Milky Way, sometimes called simply the Galaxy, is the galaxy in which our Solar System is located. It is a barred spiral galaxy that is part of the Local Group of galaxies. It is one of billions of galaxies in the observable universe.


Milky Way Galaxy
Infrared image of the core of the Milky Way galaxy
Observation data
Type
SBbc (barred spiral galaxy)
Diameter
100,000 light years
Thickness
1,000 light years (stars)
Number of stars
200 to 400 billion
Oldest known star
13.2 billion years[1]
Mass
5.8×1011 M☉
Sun's distance to galactic center
26,000 ± 1,400 light-years
Sun's galactic rotation period
220 million years (negative rotation)
Spiral pattern rotation period
50 million years[2]
Bar pattern rotation period
15 to 18 million years[2]
Speed relative to CMB rest frame
552 km/s[3]
See also: Galaxy, List of galaxies
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