Our solar system consists of an average star we call the Sun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium. The Sun is the richest source of electromagnetic energy (mostly in the form of heat and light) in the solar system. The Sun's nearest known stellar neighbor is a red dwarf star called Proxima Centauri, at a distance of 4.3 light years away. The whole solar system, together with the local stars visible on a clear night, orbits the center of our home galaxy, a spiral disk of 200 billion stars we call the Milky Way. The Milky Way has two small galaxies orbiting it nearby, which are visible from the southern hemisphere. They are called the Large Magellanic Cloud and the Small Magellanic Cloud. The nearest large galaxy is the Andromeda Galaxy. It is a spiral galaxy like the Milky Way but is 4 times as massive and is 2 million light years away. Our galaxy, one of billions of galaxies known, is traveling through intergalactic space.

INTRODUCTION

Lets start our journey

towardsSun and planets

• The Sun gives off energy as electromagnetic radiation. That includes light, infra-red energy (heat), ultraviolet light and radio waves. It also gives off a stream of particles, which reaches Earth as "solar wind". The source of all this energy is the reaction in the star which turns hydrogen into helium and makes huge amounts of energy.

• The Sun is a star like many others in our Milky Way galaxy. It has existed for a little over 4.5 billion years, and is going to continue for at least as long. The Sun is about a hundred times as wide as the Earth. It has a mass of 1.9891×1030 kg, which is 333,000 times the mass of the Earth. The Earth can also fit inside the Sun 1.3 million times.

SUN

• Mercury is the smallest planet in the Solar System.[7][8][9] It is the closest planet to the sun.[10] It makes one trip around the Sun once every 87.969 days.[1][11] Mercury is bright when it is visible from Earth, ranging from −2.0 to 5.5 in apparent magnitude. It cannot be easily seen as it is usually too close to the Sun. Because Mercury is normally lost in the glare of the Sun (except during a solar eclipse), Mercury can only be seen in the morning or evening twilight.[12]

• Compared to what is known about the other planets in the Solar System, little is known about Mercury. Telescopes on the Earth show only a small, bright crescent. The first of two spacecraft to visit the planet was Mariner 10,[13] which mapped only about 45% of the planet’s surface from 1974 to 1975. The second is the MESSENGER spacecraft, which finished mapping the planet in March 2013.

MERCURY

• Venus is the second planet from the sun.[8] It is a terrestrial planet because it haS a solid, rocky surface like other planets in the inner solar system. Astronomers have known Venus for thousands of years. The ancient Romans named it after their goddess Venus. Venus is the brightest thing in the night sky except for the Moon. It is sometimes called the morning star or the evening star as at some elongations it is easily seen just before the sun comes up in the morning and, at other elongations, just after the sun goes down in the evening. Venus comes closer to the Earth than any other planet does.

VENUS

Earth is the spherical planet we live on. It is the third planet from the sun. It is the only planet known to have life on it. Earth formed around 4.5 billion years ago. It is one of four rocky planets on the inside of the Solar System. The other three are Mercury, Venus and Mars.The large mass of the sun makes Earth move around it, just as the mass of Earth makes the moon move around it. Earth also turns around in space, so that different parts face the sun at different times. Earth goes around the sun once (one "year") for every 365¼ times it turns all the way around (one "day").Earth is the only planet in our solar system that has a large amount of liquid water.About 71% of the surface of Earth is covered by oceans. Because of this, people some times called it "blue planet".Because of its water, Earth is home to millions of species of plants and animals. The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of Earth's surface is called the "biosphere".

EARTH

• Mars is the fourth planet from the Sun in the Solar System and the second-smallest solid planet. Mars is rocky and cold, with polar ice caps of frozen water and carbon dioxide. It has the largest volcano in the Solar System, and some very large impact craters. Mars is named after the mythological Roman god of war because it is a red planet, The planet Mars is made of rock. The ground there is red because of iron oxide (rust) in the rocks and dust. The planet's atmosphere is very thin and contains a lot of carbon dioxide and a very tiny amount of oxygen. The temperatures on Mars are colder than on Earth, because it is farther away from the Sun and has less air to keep warmth in. There is water ice and frozen carbon dioxide at the north and south poles. Mars does not have any liquid water on the surface now, but signs of run-off on the surface were probably caused by water. color of blood.

MARS

• Jupiter is the largest planet in the Solar System. It is the fifth planet from the Sun.[11] Jupiter is a gas giant, both because it is so large and made up of gas. The other gas giants are Saturn, Uranus, and Neptune.Jupiter has a mass of 1.8986×1027 kg, or about 318 Earths. This is twice the mass of all the other planets in the Solar System put together.Jupiter can be seen with the naked eye. It was known to the ancient Romans, who named it after their god Jupiter (Latin: Iuppiter). Jupiter is the third brightest object in the night sky. Only the Earth's moon and Venus are brighter.Jupiter has at least 67 moons. Of these, 55 are very small and less than five kilometres wide. The four largest moons of Jupiter are Io, Europa, Ganymede, and Callisto. They are called the Galilean moons, because Galileo Galilei discovered them. Ganymede is the largest moon in the Solar System. It is larger in diameter even than Mercury.

JUPITER

• Saturn is the sixth planet from the Sun in the Solar System. It is the second largest planet in the Solar System, after Jupiter. Like Jupiter, Uranus, and Neptune, Saturn is a "gas giant".Inside Saturn is probably a core of iron, nickel, silicon and oxygen compounds, surrounded by a deep layer of metallic hydrogen, then a layer of liquid hydrogen and liquid helium and finally, an outer gaseous layer.Saturn has 62 known moons orbiting the planet; 53 are officially named. The largest moon is Titan, which is larger in volume than the planet Mercury. Titan is the second-largest moon in the Solar System. The largest moon is Jupiter's moon, Ganymede. There is also a very large system of rings around Saturn. These rings are made of ice with smaller amounts of rocks and dust. Saturn is about 1,400,000,000 km (869,000,000 mi) from the Sun. Saturn takes 29.6 years on Earth to revolve around the Sun.[2]Saturn was named after the Roman god Saturnus (called Kronos in Greek mythology). Saturn's symbol is which is the symbol of Saturnus' sickle.♄

SATURN

• Uranus is the seventh planet from the Sun in the Solar System. It is a gas giant. It is the third largest planet in the solar system. The planet is made of ice, gases and liquid metal. Its atmosphere contains hydrogen, helium and methane. The temperature on Uranus is −197 degrees C (79 K) near the top of its atmosphere, but its small solid core (about 55% the mass of Earth) is probably about 5,000K. The planet is tilted on its axis so much that it is sideways. It has five big moons, many small ones, and a small system of 13 planetary rings.The distance between Uranus and the Sun is about 2.8 billion km. Uranus completes its orbit around the Sun in 84 earth years. It completes its turn around itself in 17 hours and 14 minutes. This means there are about 43,000 Uranian days in one Uranian year.[13]Uranus was discovered in 1781. This planet can be seen with the naked eye under perfect conditions. John Flamsteed saw it decades earlier but mistook it for a star (34 Tauri).Uranus is named after the Greek god Uranus, who was a god of sky.

URANUS

• Neptune (how to say: /ˈnɛp.tjun/), is the eighth and last planet from the Sun in the Solar System. It is a gas giant. It is the fourth largest planet and third heaviest. Neptune has four rings which are hard to see from the Earth. It is 17 times heavier than Earth and is a little bit heavier than Uranus. It was named after the Roman God of the Sea.

• Neptune's atmosphere is mostly made up of hydrogen and helium. It also contains small amounts of methane which makes the planet appear blue. Neptune's blue color is much brighter compared to Uranus', which has a similar amount of methane, so there might be another reason why Neptune is blue. Neptune also has the strongest winds of any planet in the solar system, measured as high as 2,100 km/h or 1,300 mph.

NEPTUNE

JOURNEY AROUND

& IN BETWEEN

STARS

• A star is a giant ball of very hot gas. That gas is called plasma. Stars are held together by gravity. They give out heat and light because they are so hot.

• Stars are hot because of nuclear reactions happening inside them. Those reactions are called nuclear fusion. Nuclear fusion makes light and heat and makes bigger and bigger chemical elements. Stars have a lot of hydrogen. Nuclear fusion changes hydrogen into helium. When a star gets old, it starts to change the helium into other bigger chemical elements, like carbon and oxygen. Fusion makes a lot of energy. The energy makes the star very hot. The energy produced by stars moves (radiates) away from them. The energy leaves as light which we call electromagnetic radiation.

STARS

• A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to evolve gasses, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred metres to tens of kilometres across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times the Earth's diameter, while the tail may stretch one astronomical unit. If sufficiently bright, a comet may be seen from the Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures.

COMETS

• Asteroids are minor planets, especially those of the inner Solar System. The larger ones have also been called planetoids. These terms have historically been applied to any astronomical object orbiting the Sun that did not show the disc of a planet and was not observed to have the characteristics of an active comet. As minor planets in the outer Solar System were discovered and found to have volatile-based surfaces that resemble those of comets, they were often distinguished from asteroids of the asteroid belt.[1] In this article, the term "asteroid" refers to the minor planets of the inner Solar System including those co-orbital with Jupiter.

ASTEROIDS

• A meteoroid (/ˈmiːtiərɔɪd/) is a small rocky or metallic body in outer space. Meteoroids are significantly smaller than asteroids, and range in size from small grains to 1 meter-wide objects. Objects smaller than this are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars.When a meteoroid, comet, or asteroid enters Earth's atmosphere at a speed typically in excess of 20 km/s (72,000 km/h; 45,000 mph), aerodynamic heating of that object produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor or "shooting star". A series of many meteors appearing seconds or minutes apart and appearing to originate from the same fixed point in the sky is called a meteor shower. If that object withstands ablation from its passage through the atmosphere as a meteor and impacts with the ground, it is then called a meteorite.

METEOROID

• A constellation is formally defined as a region of the celestial sphere, with boundaries laid down by the International Astronomical Union (IAU). The constellation areas mostly had their origins in Western-traditional patterns of stars from which the constellations take their names.In 1922, the International Astronomical Union officially recognized the 88 modern constellations, which cover the entire sky. They began as the 48 classical Greek constellations laid down by Ptolemy in the Almagest. Constellations in the far southern sky are late 16th- and mid 18th-century constructions. 12 of the 88 constellations compose the zodiac signs, though the astronomical positions of the constellations only loosely match the dates assigned to them in astrologyThe term constellation can also refer to the stars within the boundaries of that constellation. Notable groupings of stars that do not form a constellation are called asterisms. When astronomers say something is “in” a given constellation they mean it is within those official boundaries.

CONSTELLATION

• The Moon is an astronomical body that orbits planet Earth, being Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits (its primary). Following Jupiter's satellite Io, the Moon is second-densest satellite among those whose densities are known.The average distance of the Moon from the Earth is 384,400 km (238,900 mi),[10][11] or 1.28 light-seconds.The Moon is thought to have formed about 4.51 billion years ago, not long after Earth. There are several hypotheses for its origin; the most widely accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia.

MOON

FOR TODAY ,THE JOUNEY ENDS,

HOPE YOU ENJOYED,OUR JOURNEY.

MADE BY –JANHVI SABADRACLASS-8-PREMCHAND

ROLL .NO.-27SUBJECT-SCIENCESCHOOL-L.G.E.S