ways to see the sky

how a telescope works

Learn how a telescope works to be able to observe the sky and know the best constellations. Learn more here.

earth rotation movement

earth rotation

We tell you in detail everything you need to know about the Earth's rotation. Learn more about its importance.

arcturus

Arcturus

Know in depth everything about the star Arcturus, the brightest in the whole celestial north. Here we explain everything to you. Do not miss it!

solar storm characteristics

Solar storms

In this article we tell you everything you need to know about solar storms and their characteristics. Learn more here.

kuiper belt

Kuiper Belt

We tell you everything you need to know about the Kuiper belt and what its characteristics are. Learn more about it here.

Tycho Brahe

Tycho Brahe

We tell you in detail all the biography and feats of Tycho Brahe as an astronomer. Learn more about its importance here.

explore the universe

Space rockets

In this article we tell you everything you need to know about space rockets and their characteristics. Learn more here.

neutron star

Neutron star

In this article we tell you everything you need to know about the neutron star, what it is and what its characteristics are.

Orion's belt

Orion's belt

In this article we will tell you in depth everything you need to know about the Orion belt and its characteristics. Learn more about it here.

phases of an eclipse

What is a lunar eclipse

In this article we tell you what a lunar eclipse is, its characteristics, stages, origin and some history. Learn more about it here.

types of meteorites

What is a meteorite

In this article we tell you everything you need to know about what a meteorite is, its characteristics, formation and types.

month

What is a satellite

In this article we tell you everything you need to know about what a satellite is and what types exist.

accumulation of stars

Andromeda Galaxy

We tell you everything you need to know about the Andromeda galaxy and its characteristics. Learn more about it here.

osa minor and osa major

Little Bear

In this article we will tell you all the characteristics, importance and mythology of the Ursa Minor constellation. Learn more here.

how a black hole is formed

How a black hole is formed

In this article we will tell you in detail how a black hole is formed and what its characteristics are. Learn more about it here.

heliocentrism

Heliocentrism

In this article we tell you everything you need to know about heliocentrism and its characteristics. Learn more about it here.

what is the universe

What is the universe

In this article we tell you everything you need to know about what the universe is and its characteristics. Know all the secrets here.

Saturn's rings

Saturn's rings

In this article we tell you everything you need to know about the rings of Saturn, their characteristics and discoveries.

how to choose a telescope

How to choose a telescope

We give you the best tips on how to choose a telescope according to budget, features and experience. Learn more here.

asteroid belt

Asteroid belt

We tell you everything you need to know about the asteroid belt and its characteristics. Learn more about the solar system here.

star clusters

What is a galaxy

In this article we tell you what a galaxy is and what are the characteristics and types that exist. Learn more about the universe here.

Cassini probe

Cassini probe

In this article we tell you everything you need to know about the Cassini probe and its discoveries. Learn more about it here.

helicopter to travel to mars

Ingenuity Mars

We tell you everything you need to know about Ingenuity Mars and its characteristics. Learn more about exploring Mars here.

what is the sun

What is the sun

In this article we tell you everything you need to know about what the sun is and what its characteristics are. Learn more about it here.

geminidas and their characteristics

Geminids

We tell you everything you need to know about the Geminids and their characteristics. Learn more about it here.

constellation gemini

Constellation gemini

We tell you everything you need to know about the constellation of Gemini and its characteristics. Learn more about it here.

bright star in the night sky

Star Vega

We tell you in depth everything you need to know about the Vega star and its characteristics. Learn more about it here.

Virgo major stars

Virgo constellation

In this article we teach you everything you need to know about the Virgo constellation and its characteristics. Learn more about it here.

Constellation leo

We tell you everything you need to know about the constellation Leo and its characteristics. Learn more about the stars in the sky here.

comet Neowise

Comet Neowise

In this article we will tell you everything about Comet Neowise. Learn more about it here.

constellation scorpio

Scorpio constellation

We tell you everything you need to know about the constellation of Scorpio and its characteristics. Learn more about it here.

Shooting Star

Shooting Star

In this article we tell you everything you need to know about the shooting star, its origin and characteristics. Learn more about it here.

constellation pleiades

Pleiades

We tell you everything you need to know about the constellation of Pleiades and its characteristics. Learn more about it here.

hertzsprung-russell diagram

Hertzsprung-Russell diagram

We tell you everything you need to know to interpret the Hertzsprung-Russell diagram. Learn more about the stars here.

star growth

Neutron stars

We tell you everything you need to know about neutron stars. Learn more about it here.

accretion

What is accretion

We tell you everything you need to know about accretion and its importance in the formation of stars. Learn about it here.

rocky planets of the solar system

Rocky planets

We tell you all the characteristics and classification of the rocky planets. Learn all about it here.

black hole

Event horizon

We tell you everything you need to know about the event horizon and its importance in the discovery of black holes.

White dwarf

White dwarf

We tell you everything you need to know about the white dwarf, its characteristics and formation. Learn more about it here

gas giants

Gaseous planets

We tell you everything you need to know about the gaseous planets and their characteristics. Learn more about it here.

gravitational waves

Gravitational waves

We tell you everything you need to know about gravitational waves, their characteristics and importance. Know everything here.

double stars

Double stars

We tell you everything you need to know about double stars and their characteristics. Learn more about astronomy.

types of stars and characteristics

Types of stars

In this article we will tell you all the characteristics and classification of the different types of stars that exist.

spiral galaxy features

Spiral galaxy

In this article we tell you everything you need to know about the spiral galaxy and its characteristics. Learn more about it here.

brown dwarf

Brown dwarf

We tell you the characteristics, formation and curiosities of the brown dwarf. Learn more about this celestial object.

natural satellites

Jupiter satellites

We tell you everything you need to know about the satellites of Jupiter and their characteristics. Learn more about it here.

nasa and astronauts

NASA

We tell you everything you need to know about NASA and the best space missions in history. Learn all about it here.

transit of venus

Transit of Venus

We tell you everything about the transit of Venus and how you should see it. Learn more about this astronomical phenomenon.

alignment of unique planets

Planet alignment

We tell you everything you need to know about the alignment of planets. Learn more about when this phenomenon occurs.

space race

Space race

We tell you step by step everything you need to know about the space race and the advances of the human being.

exoplanets

Exoplanets

We tell you in detail what exoplanets are and what their main characteristics are. Learn the method to discover them.

satellites of venus

Satellites of Venus

In this article we tell you some theories about the satellites of Venus and if you have ever been able to have. Meet the mystery here.

stars in the sky

What are the stars

In this article we tell you in detail what stars are and how they are formed. Learn more about the universe here.

perseids in august

Perseids

In this article we tell you everything you need to know about the Perseids and their origin. Learn more about the Meteor Shower.

irregular galaxies

Irregular galaxies

In this article we tell you everything you need to know about irregular galaxies and their formation. Learn more about it here.

saturn and rings

Planets with rings

In this article we will tell you all the characteristics and composition of the planets with rings. Learn more about it here.

how to use a celestial planisphere

Celestial planisphere

In this article we tell you what a celestial planisphere is, how it is used and how one is made. Learn about observing the sky.

andromeda constellation

Andromeda constellation

We tell you in great detail everything you need to know about the Andromeda constellation. Learn more about the set of stars in the sky.

types of galaxies

Types of galaxies

We tell you all the characteristics and the classification of the different types of galaxies that exist. Learn more about the universe here.

Order of the planets

In this article we tell you everything you need to know about the order of the planets and the characteristics of the solar system.

sun and stars

Sun characteristics

In this article we tell you all the characteristics of the sun, as well as its layers, origin and components. Learn more about it here

aries constellation

Constellation Aries

We tell you everything about the constellation of Aries in the sky. Learn more about the mythology and origin of this grouping of stars.

Aquarius constellation

Aquarius constellation

In this article we will tell you all the characteristics, origin and mythology of the constellation Aquarius. Learn more about it here.

Artificial satellites

We tell you all the characteristics, importance and uses that are given to artificial satellites. Learn more about it here.

natural satellites the moon

Natural satellites

In this post we tell you everything you need to know about natural satellites and their main characteristics. Learn more here.

vision of outer planets

Outer planets

We tell you what the outer planets are and their main characteristics. Learn more about the entire solar system.

Inner planets

In this post we show you what the inner planets are and their main characteristics. Learn more about it here.

solar storm characteristics

Solar storm

In this article we tell you what a solar storm is and how it can affect the Earth. Learn all about these phenomena here.

Circumpolar constellations

In this post we will tell you all the characteristics and how to recognize the circumpolar constellations. Learn more about astronomy here.

How to recognize the constellation Pisces

Constellation pisces

In this article we will teach you everything you need to know about the constellation Pisces. Learn more how to search for it in the sky.

Sagittarius constellation

Sagittarius constellation

We tell you everything you need to know about the constellation Sagittarius. Learn here all the characteristics and mythology of this group of stars

Sun temperature and its brightness

Sun temperature

In this article we explain what the temperature of the Sun is and how it is calculated. Learn more about the star that dominates our solar system.

Face facing the Moon

Craters on the Moon

In this post we explain in detail how craters were formed on the Moon and what characteristics the lunar surface has.

Taurus constellation

Taurus constellation

In this post you can find complete information about the constellation of Taurus. Learn to identify it and its meanings.

Heritage

Skywatcher telescopes

We make a selection of the best Skywatcher telescopes and a comparison so that you can choose the one that best suits you.

Distance from Earth and moon

We teach you the mystery of the distance from the Earth to the moon. Learn to interpret the true distance between these two celestial bodies.

Tiny planets

Tiny planets

We teach you what the dwarf planets of our solar system are. Learn what are the features they have here.

Anaximander

Biography of Anaximander

In this article you will find the biography and most important feats of the philosopher and astronomer Anaximander. Do not miss it!

Where is the Roche limit

Roche limit

Learn what the Roche limit is and its importance in astronomy. In this article we will tell you everything in detail.

The galaxy we live in is called the Milky Way.  Surely you already knew that.  But how much do you know about this galaxy we live in?  There are millions of characteristics, curiosities and corners that make the Milky Way a special galaxy.  It is our heavenly home after all, since it is where the Solar System and all the planets we know are located.  The galaxy we live in is packed with stars, supernovae, nebulae, energy, and dark matter.  However, there are many things that still remain a mystery to scientists.  We are going to tell you many things about the Milky Way, from its characteristics to curiosities and mysteries.  Profile of the Milky Way This is the galaxy that forms our home in the universe.  Its morphology is quite typical of a spiral with 4 main arms on its disk.  It is made up of billions of stars of all types and sizes.  One of those stars is the Sun.  It is thanks to the Sun that we exist and life has been formed as we know it.  The center of the galaxy is at a distance of 26.000 light years from our planet.  It is not known for sure if there could be more, but it is known that at least one supermassive hole is in the center of the Milky Way.  The black hole becomes the center of our galaxy and has been named Sagittarius A.  Our galaxy began to form about 13.000 million years ago and is part of a group of 50 galaxies known as the Local Group.  Our neighboring galaxy, called Andromeda, is also part of this group of smaller galaxies, which also includes the Magellanic Clouds.  It is still a classification made by the human being.  A species that, if you analyze the context of the entire universe and its extension, is nothing.  The Local Group mentioned above is itself part of a vastly larger gathering of galaxies.  It is called the Virgo supercluster.  The name of our galaxy is named after the luminous band that we can see of stars and gas clouds that extend above our sky through the Earth.  Although the Earth is inside the Milky Way, we cannot have as complete an understanding of the nature of the galaxy as some outer star systems can.  Much of the galaxy is hidden by a thick layer of interstellar dust.  This dust does not allow optical telescopes to focus well and discover what is there.  We can determine the structure by using telescopes with radio waves or infrared.  However, we cannot know with complete certainty what is in the region where interstellar dust is found.  We can only detect the forms of radiation that are penetrating dark matter.  Main characteristics We are going to analyze a little the main characteristics of the Milky Way.  The first thing we will analyze is the dimension.  It is shaped like a barred spiral and has a diameter of 100.000-180.000 light years.  As mentioned before, the distance to the center of the galaxy is approximately 26.000 light years.  This distance is something that human beings will never be able to travel with the life expectancy and technology that we have today.  The age of formation is estimated at 13.600 billion years, about 400 million years after the Big Bang (link).  The number of stars that this galaxy has is difficult to count.  We cannot go one by one counting all the stars there are, since it is not very useful to know exactly.  There are an estimated 400.000 billion stars in the Milky Way alone.  One of the curiosities that this galaxy has is that it is almost flat.  People who argue that the Earth is flat will be proud that this is so too.  And it is that the galaxy is 100.000 light years wide but only 1.000 light years thick.  It is as if it were a flattened and twisted disk where the planets are embedded in curved arms of gas and dust.  Something like that is the solar system, a group of planets and dust with the Sun at the center anchored 26.000 light-years from the turbulent center of the galaxy.  Who discovered the Milky Way?  It is difficult to know for sure who has discovered the Milky Way.  It is known that Galileo Galilei (link) was the first to recognize the existence of a band of light in our galaxy as individual stars in the year 1610.  This was the first real test that began when the astronomer pointed his first telescope at the sky and could see that our galaxy is made up of innumerable stars.  As early as 1920, Edwin Hubble (link) was the one who provided enough evidence to know that the spiral nebulae in the sky were actually entire galaxies.  This fact greatly helped to understand the true nature and shape of the Milky Way.  This also helped to discover the true size and to know the scale of the universe in which we are immersed.  We are also not entirely sure how many stars the Milky Way has, but it is also not very interesting to know.  Counting them is an impossible task.  Astronomers try to find the best way to do it.  However, telescopes can only see one star brighter than others.  Many of the stars are hidden behind the clouds of gas and dust that we mentioned earlier.  One of the techniques they use to estimate the number of stars is to observe how fast the stars are orbiting within the galaxy.  This somewhat indicates the gravitational pull and mass.  Dividing the mass of the galaxy by the average size of a star, we will have the answer.

Milky Way

We tell you all the most curious about the Milky Way, our galaxy. Enter here to learn more about the universe where we live.

One of the layers of the atmosphere that protects us is the ionosphere.  It is a region that contains a large number of atoms and molecules that are charged with electricity.  These charged particles are created thanks to radiation that comes from outer space, mainly from our star the Sun.  This radiation hits the neutral atoms and air molecules in the atmosphere and ends up charging them with electricity.  The ionosphere is of great importance for humans and, therefore, we are going to dedicate this entire post to it.  We are going to explain everything you need to know about the characteristics, operation and importance of the ionosphere.  Main Features While the Sun is shining continuously, during its activity it is generating a large amount of electromagnetic radiation.  This radiation falls on the layers of our planet, charging the atoms and molecules with electricity.  Once all the particles are charged, a layer forms that we call the ionosphere.  This layer is located between the mesosphere, the thermosphere and the exosphere.  More or less you can see that it begins at a height of about 50 km above the earth's surface.  Although it starts at this point, where it becomes more complete and important is above 80 km.  In the regions that we are in the upper parts of the ionosphere we can see hundreds of kilometers above the surface that extend tens of thousands of kilometers into space is what we call the magnetosphere.  The magnetosphere is the layer of the atmosphere that we call this way because of its behavior due to the Earth's magnetic field (bond) and the action of the Sun on it.  The ionosphere and the magnetosphere are related by the charges of the particles.  One has electrical charges and the other has magnetic charges.  Layers of the ionosphere As we have mentioned before, although the ionosphere begins at 50 km, it has different layers depending on the concentration and composition of the ions that form it.  Previously, the ionosphere was thought to be made up of several different layers that were identified by the letters D, E, and F.  The F layer was divided into two more detailed regions which were F1 and F2.  Today, more knowledge is available of the ionosphere thanks to the development of technology and it is known that these layers are not very different.  However, in order not to make people dizzy, the original scheme that was had in the beginning is maintained.  We are going to analyze part by part the different layers of the ionosphere to see in detail their composition and importance.  Region D This is the lowest part of the entire ionosphere.  It reaches altitudes of between 70 and 90 km.  Region D has different characteristics than regions E and F.  This is because its free electrons almost completely disappear overnight.  They tend to disappear as they combine with oxygen ions to form oxygen molecules that are electrically neutral.  Region E This is the layer also known as Kennekky-Heaviside.  This name has been given in honor of the American engineer Arthur E.  Kennelly and the English physicist Oliver Heaviside.  This layer extends more or less from 90 km, where layer D ends up to 160 km.  It has a clear difference with the D region and is that the ionization remains throughout the night.  It should be mentioned that it is also quite reduced.  Region F It has an approximate altitude from 160 km to the end.  It is the part that has the highest concentration of free electrons since it is the closest to the sun.  Therefore, it perceives more radiation.  Its degree of ionization does not have many changes during the night, since there is a change in the distribution of the ions.  During the day we can see two layers: a smaller layer that is known as F1 that is higher up and, another highly ionized dominant layer that is known as F2.  During the night both are fused at the level of the F2 layer, which is known as Appleton.  Role and importance of the ionosphere For many, having a layer of the atmosphere that is electrically charged may not mean anything.  However, the ionosphere is of great importance for the development of humanity.  For example, thanks to this layer we can propagate radio waves to different places on the planet.  We can also send the signals between the satellites and the Earth.  One of the most important factors why the ionosphere is fundamental for humans is because it protects us from dangerous radiation from outer space.  Thanks to the ionosphere we can see beautiful natural phenomena such as the Northern Lights (link).  It also protects our planet from the celestial rock masses that enter the atmosphere.  The thermosphere helps us protect ourselves and regulate the Earth's temperature by absorbing some of the UV radiation and X-rays that are emitted by the Sun.  On the other hand, the exosphere is the first line of defense between the planet and the sun's rays.  The temperatures in this much-needed layer are extremely high.  At some points we can find 1.500 degrees Celsius.  At this temperature, apart from the fact that it is impossible to live, it would burn every human element that passed by.  This is what causes a large part of the meteorites that hit our planet to disintegrate and form shooting stars.  And it is that when these rocks come into contact with the ionosphere and the high temperature at which it is found in some points, we find the object becomes somewhat incandescent and surrounded by fire until it ends up disintegrating.  It really is a very necessary layer for human life to develop as we know it today.  For this reason, it is important to know her more thoroughly and study her behavior, since we could not live without her.

Ionosphere

In this post we show you what are the main characteristics of the ionosphere and the importance it has for humans.

Messier Catalog

Charles Messier

In this article we show you the biography and exploits of Charles Messier. Learn here everything about the life of this astronomer.

Moons of mars

Moons of mars

In this post we tell you what the moons of Mars are, their characteristics, origin and curiosities. Do not miss more about it!

Edmund Halley Biography

Edmund halley

In this post we show you the biography of Edmund Halley. Enter here to know all his contributions in science and his discoveries.

Saturn's rings

Moons of saturn

Know everything you need to know and did not know about the moons of Saturn. The ringed planet is discovered in depth in this post. Do not miss it!

Bright supernova

Supernova

We explain everything you need to know about the supernova. Enter here to learn the curiosities and secrets of star explosions.

Moon and its surface

Apollo missions

In this article we are going to explain the characteristics and importance of the Apollo missions for humanity.

Aristarchus of Samos on statue

Aristarchus of Samos

In this article we explain the exploits and biography of Aristarco de Samos. Enter here to learn everything about this mathematician and astronomer.

The face of the moon that we can only see

Movements of the moon

Here we explain in detail what the movements of the moon are and the consequences they have on planet Earth. Get to know them thoroughly.

Light years away

Distance from Earth to Sun

In this article we show you what the distance from the Earth to the Sun is. We also explain the methods to calculate it.

Asteroid

Asteroids

In this article we teach you everything you need to know about asteroids and their formation. We also clarify your doubts about meteorites.

Eratosthenes

Eratosthenes

In this post you can find the entire biography of Eratosthenes. Learn about the discoveries he made and his contribution to science.

Galileo Galilei and the contribution to astronomy

Galileo Galilei

We tell you in great detail the entire biography of Galileo Galilei. Enter here to see all the life and work of Galileo.

Collision of matter and antimatter

Antimatter

In this post you can find everything related to antimatter. Enter here and discover its secrets and mysteries. Do not miss it!

Johannes Kepler

Johannes Kepler

Enter here to know in detail the biography of Johannes Kepler. Meet the astronomical scientist who drew up Kepler's laws.

astrolabe

Astrolabe

Enter here to find out what an astrolabe is, what characteristics it has, how it works and what types are there. Do not miss it!

Black hole dynamics

Black holes

In this post we explain what black holes are and how they are formed. Enter here to debunk the myths of black holes.

Earth center of the universe

Geocentric theory

Enter here to learn everything about geocentric theory. Learn its characteristics and compare some aspects with the Bible.

Theory of the center of the universe

Nicolaus Copernicus

We explain the biography of Nicolás Copernicus in detail. Enter here and learn all about his work on the heliocentric theory.

Measure the distance between stars

Azimuth

We explain what the concepts of azimuth, elevation and heading are and what they are for. In addition, we teach you the instruments with which to measure in the sky.

Position of the Earth in its orbit

Perihelion and aphelion

Enter here and learn everything about the importance of perihelion and aphelion in the earth's balance. We tell you everything in detail.

Hubble space telescope

Hubble space telescope

Enter here to learn about the characteristics, evolution and great discoveries that the Hubble Space Telescope has brought to science.

Existence of life on other planets

Fermi paradox

In this post we explain everything you need to know about the Fermi paradox. Enter and know the possible solution to the existence of life.

Giordano Bruno

Giordano Bruno

In this article we explain the history and achievements of Giordano Bruno. Enter and know everything about his life and his cruel death.

Characteristic of wormholes

Wormholes

In this article we explain what wormholes are and how they work. Enter here and learn about it and if we can travel back in time.

Mount Olympus

Mount Olympus from Mars

Mount Olympus is located on the planet Mars. It is the largest in the entire Solar System. Here we tell you everything about him in detail.

Planet neptune

The planet Neptune

We tell you everything you need to know about the planet Neptune. It is the planet furthest from the Solar System. Enter and discover all its secrets.

Cassiopeia W shape

The constellation Cassiopeia

Cassiopeia is one of the most famous constellations in the sky in the Northern Hemisphere. Enter here and know all its characteristics and mythology.

Halley comet

Halley's Comet

Halley's Comet is the most famous that has ever been sighted. In this article you can learn everything about him and his origin.

blue Moon

blue Moon

The blue moon is an astronomical event that takes place when there are two full moons in the same month. Enter here and know everything about it.

Polar Star

Polar Star

The Polar Star belongs to the constellation Ursa Minor. Enter here and learn everything about its usefulness, history and how to identify it.

Where the sun rises

Where the sun rises

We have always wondered where the Sun rises and where it sets. In this post you will be able to know the reality on the subject. Come in and learn everything.

stars in the sky

Constellations in the sky

Constellations are imaginary shapes that stars take in the night sky. Enter here because we explain everything in detail about them.

formation of the earth

How the Earth was created

In this post you can learn everything about how the Earth was created. Learn more about our planet and how it has evolved over the years.

Uranus planet

The planet Uranus

The planet Uranus is one of those that make up our solar system, in addition to being one of the most remote. Do you want to know more about him?

Contributions on the expansion of the Hubble universe

Edwin hubble

Edwin Hubble was a scientist who made great contributions to astronomy that are still present today. Enter here to know everything about him.

Moon phases

Moon phases

The best known phases of the moon are new moon, first quarter, full moon and last quarter. Know here everything about them.

Pluto

The "planet" Pluto

Pluto was considered a planet for 75 years after its discovery. Know here all the characteristics and curiosities.

Nebulae

Nebulae

Nebulae are clouds of stellar dust and gas found in our Universe. Know their training and types in this post.

Planet venus

The planet Venus

The planet Venus is the second closest to the Sun in our Solar System. It has similarities with our planet. Do you want to discover everything about the planet?

Saturn planet

The planet Saturn

The planet Saturn is one of the most interesting in the entire solar system and famous for its rings. Do you want to know everything about him? Enter here.

Planet Mars

Mars

In this post we analyze in depth all the characteristics of the planet Mars and the possible existence of life. Enter and learn everything about him.

Planet Mercury

The planet Mercury

The planet Mercury is the smallest and closest to the Sun in our solar system. Learn all its characteristics and curiosities.

Planet Jupiter

The planet Jupiter

The planet Jupiter is the largest in the entire solar system. Learn all the characteristics, composition and dynamics in this article.

Great Bear

Great Bear

The Big Dipper is the most famous constellation in the world. Learn all its history, how to see it and where in this article. Enters :)

Big Bang Theory

Big Bang Theory

The Big Bang theory is well known throughout the world and it is what explains the origin of the universe. Do you want to know it in summarized format? Enter here.

Solar system

The solar system

The solar system is made up of a collection of planets, the Sun, and other objects. Do you want to know more about the part of the universe where we live?

Lunar calendar 2018

Lunar calendar 2018

Here you can know the exact dates of the different phases of the moon throughout the year. Read the post if you want to know the 2018 lunar calendar.