The Universe is all of spacetime and everything that exists therein, including all planets, stars, galaxies, the contents of intergalactic space, the smallest subatomic particles, and all matter and energy. Similar terms include the cosmos, the world, reality, and nature. The observable universe is about 46 billion light years in radius.Scientific observation of the Universe has led to inferences of its earlier stages. These observations suggest that the Universe has been governed by the same physical laws and constants throughout most of its extent and history. The Big Bang theory is the prevailing cosmological model that describes the early development of the Universe, which is calculated to have begun 13.798 ± 0.037 billion years ago.Observations of supernovae have shown that the Universe is expanding at an accelerating rate.[10] There are many competing theories about the ultimate fate of the universe. Physicists remain unsure about what, if anything, preceded the Big Bang. Many refuse to speculate, doubting that any information from any such prior state could ever be accessible.[citation needed] There are various multiverse hypotheses, in which some physicists have suggested that the Universe might be one among many, or even an infinite number, of universes that likewise exist.

2.  According to the prevailing scientific
model Of The Universe, known as the Big
Bang, the Universe expanded from an
extremely hot, dense phase called the
Planck epoch, in which all the matter and
energy of the observable universe was
concentrated.
 The universe is composed of ordinary
matter (5%) including atoms, stars, and
galaxies, dark matter (25%) which is a
hypothetical particle that has not yet been
detected, and dark energy (70%), which is a
kind of energy density that seemingly exists

3. The Universe is commonly defined as the totality of existence,
including planets, stars, galaxies, the contents of intergalactic
space, and all matter and energy. Similar terms include the
cosmos, the world and nature.
The observable universe is about 46 billion light years in radius.
Scientific observation of the Universe has led to inferences of its
earlier stages. These observations suggest that the Universe has
been governed by the same physical laws and constants
throughout most of its extent and history. The Big Bang theory is
the prevailing cosmological model that describes the early
development of the Universe, which is calculated to have begun
13.798 ± 0.037 billion years ago. Observations of a supernovae
have shown that the Universe is expanding at an accelerating
rate.

4. There are many components of the universe which includes solar
systems, galaxies, countless numbers of stars , and so many other
planets which we have never heard of. There are about 8 planets
namely :- Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus and
Neptune. There are also some dwarf planets such as Ceres.

5. Picture of the Sun

6. Our Solar System

7. 1.The universe began with the Big Bang, and is estimated to be
approximately 13.7 billion years old (plus or minus 130 million years).
2. The shape of the universe is influenced by the struggle between the pull
of gravity (based on the density of the matter in the universe) and the rate
of expansion. If the density of the universe exceeds a certain critical
value, then the universe is "closed," like the surface of a sphere.
3.The universe is overwhelmingly made up of things that cannot be seen.
In fact, the stars, planets and galaxies that can be detected make up only
4 percent of the universe, according to astronomers. The other 96 percent
is made up of substances that cannot be seen or easily comprehended.
4. The planet Venus is has a temperature of over 500°C

9.  A constellation is a group of stars that, when seen
from Earth, form a pattern. The stars in the sky are
divided into 88 constellations.
 The brightest constellation is Crux (the Southern
Cross).
 The constellation with the greatest number of
visible stars in it is Centaurus (the Centaur - with
101 stars). The largest constellation is Hydra (The
Water Snake) which extends over 3.158% of the sky.

10.  Ursa Major and Ursa Minor
 ORION
 SAGITTARIUS
 GEMINI

11. The Solar System comprises of the
Sun and its planetary system of
eight planets,as well as a number of
dwarf planets, satellites (moons),
and other objects that orbit the Sun.

12. 1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune
 Now the planet Pluto which was earlier
considered a planet is now classified as dwarf
planet.

13.  Sun
The Sun is the star at the center of the Solar
System. It is almost perfectly spherical and
consists of hot plasma interwoven with magnetic
fields. It has a diameter of about 1,392,684 km
(865,374 mi), around 109 times that of Earth, and its
mass (1.989×1030 kilograms, approximately 330,000
times the mass of Earth) accounts for about 99.86%
of the total mass of the Solar System. Chemically,
about three quarters of the Sun's mass consists of
hydrogen, while the rest is mostly helium. The Sun
formed about 4.6 billion[a] years ago from the
gravitational collapse of a region within a large
molecular cloud.

14. Most of the matter gathered in the center, while the
rest flattened into an orbiting disk that would become
the Solar System. Once regarded by astronomers as a
small and relatively insignificant star, the Sun is now
thought to be brighter than about 85% of the stars in
the Milky Way galaxy, most of which are red dwarfs.
The absolute magnitude of the Sun is +4.83; however,
as the star closest to Earth, the Sun is the brightest
object in the sky with an apparent magnitude of
−26.74.

15.  Moon
The Moon is the only natural satellite of the
Earth and the fifth largest moon in the Solar
System. It is the largest natural satellite of a
planet in the Solar System relative to the size
of its primary, having 27% the diameter and
60% the density of Earth, resulting in 1⁄81 its
mass. Among satellites with known densities,
the Moon is the second densest, after Io, a
satellite of Jupiter. It is the brightest object in
the sky after the Sun, although its surface is
actually dark, with a reflectance just slightly
higher than that of worn asphalt.

16. Its prominence in the sky and its regular cycle of
phases have, since ancient times, made the Moon an
important cultural influence on language, calendars,
art and mythology. The Moon's gravitational influence
produces the ocean tides and the minute lengthening
of the day. The Moon is thought to have formed nearly
4.5 billion years ago, not long after the Earth.
Although there have been several hypotheses for its
origin in the past, the current 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.

18. An eclipse is an astronomical event that occurs
when an astronomical object is temporarily
obscured, either by passing into the shadow of
another body or by having another body pass
between it and the viewer. An eclipse is a type of
syzygy.
There are two types of eclipses :-
 Solar Eclipse
 Lunar Eclipse

19. As seen from the Earth, a solar eclipse occurs
when the Moon passes between the Sun and
Earth, and the Moon fully or partially blocks
the Sun. This can happen only at new moon,
when the Sun and the Moon are in conjunction
as seen from Earth in an alignment referred to
as syzygy. In a total eclipse, the disk of the
Sun is fully obscured by the Moon. In partial
and annular eclipses only part of the Sun is
obscured.

20. A lunar eclipse occurs when the Moon passes
directly behind the Earth into its umbra (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, a lunar eclipse can
only occur the night of a full moon. The type and
length of an eclipse depend upon the Moon's
location relative to its orbital nodes. Unlike a solar
eclipse, which can only be viewed from a certain
relatively small area of the world, a lunar eclipse
may be viewed from anywhere on the night side
of the Earth.

21. As the moon circles the Earth, the shape of the
moon appears to change; this is because different
amounts of the illuminated part of the moon are
facing us. The shape varies from a full moon
(when the Earth is between the sun and the
moon) to a new moon (when the moon is between
the sun and the Earth).

22. Crescent Moon - When we can see only a
sliver of the moon's disk (the side of the
moon facing us) Full Moon - when the
moon's disk is light because the Earth is
between the sun and the moon .
Gibbous Moon - When we can see roughly
three-quarters of the moon's disk .
Half Moon - (Also called quarter moon) when
we can see one half of the moon's disk (this
is one-quarter of the entire moon's surface) .

23. New Moon - When the moon's disk is dark
(and invisible to us) because the moon is
between the sun and the Earth Quarter Moon -
(also called half moon) when we can see one
half of the moon's disk (this is one-quarter of
the entire moon's surface) .
Waning Moon - When the moon seems to be
getting smaller, going from full to gibbous to
half to crescent to new .
Waxing Moon - When the moon seems to be
getting bigger, going from new to crescent to
half to gibbous to full .

25. A galaxy is a massive, gravitationally
bound system consisting of stars, stellar
remnants, an interstellar medium of gas
and dust, and dark matter, an important but
poorly understood component. The word galaxy
is derived from the Greek galaxias ), literally
"milky", a reference to the Milky Way. Examples
of galaxies range from dwarfs with as few as
ten million stars to giants with one
hundred trillion stars, each orbiting their
galaxy's own center of mass.