This document provides information about various topics related to space, including the universe, galaxies, the Milky Way galaxy, planets, stars, the solar system, and constellations. It describes the universe as gigantic containing billions of galaxies. It defines galaxies as massive ensembles of hundreds of millions of stars orbiting a common center, with the Milky Way galaxy containing billions of stars and clouds of gas and dust. It also describes the eight major planets in our solar system and characteristics of stars, black holes, comets, and constellations visible in the northern hemisphere sky.

1. SPACE
THE MYSTERIOUS ZONE
NAME: VANSHU MUGVANA
ROLL NUMBER: 30
CLASS: VIII

2. UNIVERSE
THE UNIVERSE IS GIGANTIC. IT CONTAINS EARTH,
THE PLANETS, THE STARS, AND EVERYTHING ELSE IN
OUTER SPACE. THE UNIVERSE IS SO BIG THAT A
SPACESHIP COULDTRAVEL FOR BILLIONS OF YEARS
WITHOUT REACHINGTHE END OFIT. IT MIGHT EVEN
GO ONFOREVER!

3. GALAXY
Galaxy, a massive ensemble of hundreds of millions of stars, all gravitationally interacting,
and orbiting about a common center. Astronomers estimate that there are about 125 billion
galaxies in the universe. All the stars visible to the unaided eye from Earth belong to Earth’s
galaxy, the Milky Way. The Sun, with its associated planets, is just one star in this galaxy.
Besides stars and planets, galaxies contain clusters of stars; atomic hydrogen gas; molecular
hydrogen; complex molecules composed of hydrogen, nitrogen, carbon, and silicon, among
others; and cosmic rays.

4. MILKY WAY
The Milky Way is a huge group of stars called a galaxy. There
are billions of stars in the Milky Way. The Sun and all
nearby stars are part of the Milky Way Galaxy. There are
also huge clouds of gas and dust in between the stars. New
stars form in the clouds of gas and dust.
The Milky Way Galaxy is shaped like a thick disk turning in
outer space.

5. WHAT ARE PLANETS?
Planet, a round body in space that orbits a star. To be a
planet, a body must be big enough to settle into a rounded
shape from the inward pull of its own gravitation. A planet
shines by reflecting light and not by releasing nuclear energy
the way a star does. Our solar system has eight major
planets—Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus, and Neptune—and a number of small, dwarf
planets, including Pluto, Eris, and Ceres. A planet-like body
that revolves around a larger planet is called a satellite or
moon rather than a planet. Jupiter from Pioneer 10
Planets are distinct from asteroids and comets, smaller
bodies that also orbit stars.

6. STARS
A star is a big ball of hot, glowing gas. The gas is mostly hydrogen
and helium. Stars give off heat, light, and other kinds of energy.
A star has several layers. The part at the center of a star is called its
core. A star shines because of its core. The core is so hot and tightly
packed that atoms crunch together. Atoms are tiny bits of matter
much too small to see. Hydrogen atoms crunch together and
become helium atoms. This is called nuclear fusion. Nuclear fusion
gives off enough energy to make the stars shine.

7. SOLAR SYSTEM
Solar System, the Sun and everything that orbits the Sun,
including the planets and their satellites; the dwarf planets,
asteroids, Kuiper Belt Objects, and comets; and interplanetary
dust and gas. The term may also refer to a group of celestial
bodies orbiting another star (see Extra solar Planets). In this
article, solar system refers to the system that includes Earth
and the Sun.

8. THE SUN
The sun is in the centre of the solar system. It is huge and made up of
extremely hot gases. It provides the pulling force that blinds the solar system.
The sun is the ultimate source of heat and light for the solar system. But that
tremendous heat is not felt so much
by us because despite being our nearest star, it is far away from us. The sun is
about 150 million km away from the earth.
.

9. THE EIGHT PLANETS
MERCURY
Mercury orbits closer to the Sun than any other planet, making it dry, hot, and
virtually airless. Although the planet’s cratered surface resembles that of the Moon, it
is believed that the interior is actually similar to Earth’s, consisting primarily of iron
and other heavy elements. This composite photograph was taken in 1974 by Mariner
10, the first probe to study Mercury in detail.

10. VENUS
Venus is the brightest object in our sky, after the sun and moon. Swirling clouds
of sulfur and sulfuric acid obscure Venus’s surface and inhibited study of the
planet from Earth until technology permitted space vehicles, outfitted with
probes, to visit it. These probes determined that Venus is the hottest of the
planets, with a surface temperature of about 460° C (about 860° F). Scientists
believe that a greenhouse effect causes the extreme temperature, hypothesizing
that the planet’s thick clouds and dense atmosphere trap energy from the sun.

11. EARTH
An oxygen-rich and protective atmosphere, moderate temperatures, abundant
water, and a varied chemical composition enable Earth to support life, the only
planet known to harbor life. The planet is composed of rock and metal, which
are present in molten form beneath its surface. The Apollo 17 spacecraft took
this snapshot in 1972 of the Arabian Peninsula, the African continent, and
Antarctica [most of the white area near the bottom].

12. MARS
The most detailed information available about Mars has
come from unpiloted spacecraft sent to the planet by the
United States. From this data, scientists have determined
that the planet’s atmosphere consists primarily of carbon
dioxide, with small amounts of nitrogen, oxygen, water
vapor, and other gases. Because the atmosphere is
extremely thin, daily temperatures can vary as much as
100 Celsius degrees (190 Fahrenheit degrees). In general,
surface temperatures are too cold and surface pressures
too low for water to exist in a liquid state on Mars. The
planet resembles a cold, high-altitude desert.

13. ASTEROID BELT
Asteroids are big pieces of rock and metal in space.
There are thousands of them between Mars and
Jupiter in an area called the asteroid belt. They go
around the Sun just like planets do.

14. JUPITER
Jupiter is the largest of the planets, with a volume more
than 1,300 times greater than that of Earth. Jupiter’s colorful
bands are caused by strong atmospheric currents and
accentuated by a dense cloud cover. The massive planet,
upper right, is shown here with its four largest satellites: Io,
upper left, Ganymede, lower left, Europa, center, and
Callisto, lower right.

15. SATURN
Saturn, distinguished by its rings, is the second largest planet in
the solar system. This processed Hubble Space Telescope image
shows the planet’s cloud bands, storms, and rings as they would
appear to the human eye.

16. URANUS
Uranus’s blue-green color comes from the methane gas present in
its cold, clear atmosphere. The dark shadings at the right edge of
the sphere correspond to the day-night boundary on the planet.
Beyond this boundary, Uranus’s northern hemisphere remains in a
four-decade-long period of darkness because of the way the
planet rotates. Scientists compiled this view of Uranus from
images returned from Voyager 2 in 1986, when the probe was 9.1
million km (5.7 million mi) away from the planet.

17. NEPTUNE
This image of Neptune, taken by the Voyager 2 spacecraft, shows the planet’s most
prominent features. The large, dark oval surrounded by white clouds near the
planet’s equator is the Great Dark Spot, a storm similar to Jupiter’s Great Red Spot.
The smaller dark oval with a bright core below and to the right of the Great Dark
Spot is another storm known as Dark Spot 2.

18. The Kuiper Belt is a disk-shaped collection of
small, icy objects in the outer solar system.
The belt extends from just inside Neptune’s
orbit far beyond the orbit of Pluto.
KUIPER BELT

19. CONSTELLATION
People have grouped stars into imagined patterns,
called constellations, since ancient times. Ancient
people created these patterns to remember
important people and events. Click on the arrows
to learn more about some of the constellations
that appear in the skies of the Northern
Hemisphere. Following are the name of the
constellations ,which people have grouped since
ancient times:-

20. 1. BIG DIPPER-
The Big Dipper is a constellation of seven stars in
the northern celestial hemisphere. It is also known
by the names Ursa Major (the Great Bear), the
Plow, Charles’s Wain, and the Wagon. In Hinduism,
the seven stars in the constellation represent the
seven rishis, or holy ancient sages.

21. 2. URSAMAJOR-
Ursa Major is made up of many stars that
appear to form the shape of a bear. Ursa
Major contains the Big Dipper, a group of
seven stars in the shape of a large cup with a
long handle. The handle of the dipper forms
the bear’s tail and the cup is located near the
bear’s rear end. Ursa Major is best seen in the
summer months.

22. 3. PEGASUS-
Pegasus (astronomy), northern constellation,
situated southeast of Andromeda. The three
brightest stars of Pegasus, α Pegasi, or Markab, β
Pegasi, or Scheat, and g Pegasi, or Algenib, form a
square with α Andromedae, called the square of
Pegasus. The constellation, which is named for the
winged horse of Greek mythology, is usually seen
upside down in the sky, with only the head, neck,
and front half of the animal represented by the
stars.

23. 4. ORION-
Orion, named for a famous hunter in Greek
mythology, is the brightest constellation in the
winter sky. It includes eight bright stars in the
shape of an hourglass. According to legend, three
stars in a row form the belt of Orion.

24. 5. CYGNUS
Cygnus (Latin, “swan”), prominent northern constellation that
lies mostly within the Milky Way. Cygnus is seen best during
early September, when it reaches its highest point in the
evening sky. It contains the bright first magnitude star Deneb
and a group of six stars that form a Latin cross known as the
Northern Cross. Cygnus contains many interesting objects
including 61 Cygni, the first star (other than the sun) to have its
distance from earth calculated. Cygnus also contains one of the
most powerful radio sources in the sky, Cygnus A and a strong
X-ray source, Cyg X-1, thought to be a black hole.

25. BLACK HOLE
Black Hole, an extremely dense celestial body that has
been theorized to exist in the universe. The gravitational
field of a black hole is so strong that, if the body is large
enough, nothing, including electromagnetic radiation, can
escape from its vicinity. The body is surrounded by a
spherical boundary, called a horizon, through which light
can enter but not escape; it therefore appears totally
black.

26. COMETS
Comet, small icy body in space that sheds gas and
dust. Like rocky asteroids, icy comets are ancient
objects left over from the formation of the solar
system about 4.6 billion years ago. Some comets can
be seen from Earth with the unaided eye.
Comets typically have highly elliptical off-center
orbits that swing near the Sun. When a comet is
heated by the Sun, some of the ice on the comet’s
surface turns into gas directly without melting.
Comets were long regarded as supernatural
warnings of calamity or signs of important events.

27. Some of the comets are:-

28. I HOPE YOUENJOYEDMY
PRESENTATION ABOUT
SP AC E .
THANK YOU.
CREATED BY- VANSHU MUGVANA
OF CLASS VII