2. MAHATMA GANDHI MISSION’S
COLLEGE OF ENGINEERING AND TECHNOLOGY
KAMOTHE, NAVI MUMBAI - 410209.
Electronics & Telecommunication Department
T.E. / A
GROUP 1
A Report on ANCIENT AND MODERN ASTRONOMY
SUBMITTED TO
PROF. SRIDEVI NAIR.
DATE OF SUBMISSION: 10 September 2014.

3. A PROJECT REPORT ON
ANCIENT AND MODERN
ASTRONOMY:
A Quest To Understand The Universe
PREPARED BY:
1. Madhuri Aldar
2. Amrut Anantwar
3. Anjali Ayambara
4. Nimish Bagwe
5. Aditya Bali
6. Kshitij Bane (Group Leader)
7. Lalita Bhondivale
MGM’s College of Engineering and Technology
Kamothe, Navi Mumbai-410209
Electronics And Telecommunication Engineering Department

4. I
PREFACE
The report “Ancient & Modern Astronomy” refers to
the study of celestial objects outside the boundaries of our
Earth, how ancient civilizations made great discoveries
through observations & how modern means have made us
able to understand the universe.
We have made sincere attempts and take every care to
present this matter in precise and compact form, the language
being as simple as possible.
We are sure that the information contained in this report
would certainly prove useful for better insight of this topic
which most of the common people find complicated.
The task completion of the report though being difficult
was made quite simple, interesting and successful due to deep
involvement and complete dedication of our group members.

5. II
ACKNOWLEDGEMENT
It’s been a privilege working under Sridevi Madam for
developing this report. Taking this opportunity to express
our deep sense of gratitude and thankfulness to our guide Ms.
Sridevi Nair for timely and valuable guidance which help us
to complete our report.
Thanks to our respected principal Dr. S. K. Narayankhedkar
and our HoD Dr. B. Dubey sir for this support and facilities
provided to us for the report and Sridevi madam your
incorporable measure of the knowledge has really helped us to
bestow our report.
Lastly thanks to our group members who helped us to
make this project work of great appraisal to be recognized as
one of our identity.

6. III
TABLE OF CONTENTS
A) PREFACE I
B) ACKNOWLEDGEMENT II
C) ABSTRACT IV
1) INTRODUCTION 1
2) ANCIENT ASTRONOMY 3
2.1 Early Astronomy 4
2.2 Ancient Indian Astronomy 8
2.3 The Copernican Revolution 11
3) THE SPACE AGE 16
4) THE SOLAR SYSTEM 18
5) THE UNIVERSE 30
5.1 Galaxies 31
5.2 Stars 35
5.3 Nebulae 38
6) UNSOLVED MYSTERIES 40
6.1 The Big Bang Theory 40
6.2 Dark Matter & Dark Energy 42
6.3 Quasars & Wormholes 44
6.4 End of the Universe 45
CONCLUSION 46
BIBLIOGRAPHY 47

7. IV
ABSTRACT
Astronomy studies the universe beyond Earth, including the
formation, development & evolution along with the physics
& chemistry of celestial objects such as Stars, Planets,
Galaxies & awe inspiring phenomena like Nebulae,
Supernovas, Black Holes & Quasars.
Astronomy was an integral part of many early civilizations. It
was connected to the religious & spiritual outlook of the
world. It was believed that the heavenly bodies have
powerful influence upon human life.
Throughout these years we have made great discoveries
regarding the celestial bodies. We have developed many
theories explaining how & why we are here. Our knowledge
of what lies beyond the boundaries of earth may be
considerable, yet we are still fascinated about the space.
There is still a sense of awe towards the universe.
This report will take us on a journey of discoveries, a voyage
through the time, a quest to understand the universe.......

8. 1
1. INTRODUCTION
Astronomy is arguably the oldest science. The night skies &
astronomical bodies have been a source of wonder & speculation
since the development of early civilizations. The term ‘Astronomy’
derives from an ancient Greek phrase meaning the laws or science
governing the stars. However, Astronomy is not just the study of
stars; rather it is the study of all the celestial phenomena.
Today we might say that astronomy is our attempt to study and
understand celestial phenomena, part of the never-ending urge to
discover order in nature. We do not know who were the first
astronomers—what we do know is that the science of astronomy
was well advanced in parts of Europe by the middle of the third
millennium BC and that the Chinese people had astronomical schools
as early as 2000 BC. In all ages, from the burgeoning of man’s
intelligence, there have been people fascinated by the heavens and
their changing aspect and these people, as far as their cultural
environment has allowed them, have tried to formulate cosmologies.
We are no different today.
The Sun, with its life giving energy, was deified, its daily journey
across the skies imbued with religious significance. The ancient
Egyptian were the first to calculate the length of a solar year, adding
five days to their original 360-days calendar, a margin of error of just
six hours. Where myth & mysticism led, scientific discovery was
quickly followed.
5000 years on, our knowledge of the Solar system and what lies
beyond may be considerable, yet the sense of awe is hardly less than
that experienced by the earliest observers.

9. 2
If our current theories of the Universe are nearer the truth, it is
probably not that our intelligence has increased in the past six
millennia. It is more likely that the main factor has been the
discovery and development of the ‘scientific method’, which has led
to our present civilization based on the flood of technological
advantages provided by this method. This has enabled scientists in
far greater numbers than ever before to devote their lives to the
study of the heavens, assisted by telescopes, computers, space
vehicles and a multitude of other equipment. Their attempts to
interpret and understand the wealth of new information provided by
these new instruments have been aided by allied sciences such as
physics, chemistry, geology, mathematics and so on...
The canvas of space & time is vast; 15 billion years since the Big
Bang, when the entire universe occupied the space of a sub-atomic
particle; 4.5 billion years since a cloud of gas & dust collapsed to
form the star which sustains life on Earth. To study an object in deep
space is to see hundreds of millions of years into the past.

10. 3
2. ANCIENT ASTRONOMY
Astronomy is the science of understanding everything that goes on
beyond Earth’s boundaries. It is one of the oldest of sciences. Every
civilization, through antiquity to the recent past, had stunning views
of stars night after night, as sightings of the cosmos would not have
been hampered by the light pollution and an indoor life style, both of
which hide much of the heavens from observers today. All over the
world some sort of the understanding of the celestial sphere was an
integral part of civilization, whether or not they opted for scientific
explanations of the observed phenomena.
We must remember, however, that for more than nine-tenths of
the last five thousand years of our study of the heavens, we have had
to rely on the unaided eye. The Mediterranean people who set the
constellations in the sky, the Babylonians, Egyptians and Greeks, the
Arabian astronomers who flourished during the Dark Ages of Post-
Roman Europe, the Chinese, the Mayan, the Indians and other early
American astronomers, all built their theories of the Universe on
naked eye observations.

11. 4
2.1 EARLY ASTRONOMY
Ancient China
Ancient Chinese civilizations paid
close attention to the night sky
because an important part of the
culture’s philosophy was the idea
of harmony between man and nature.
 Oldest established culture with recorded astronomical
observations.
 First people to record solar eclipse, Super Nova, Stellar
positions in a catalogue.
Chinese mythology held that an eclipse occurred when a
dragon was eating the sun and that only way to defeat
the dragon was to make as much noise as possible. In
the event of an eclipse, people would make a mighty
racket, which would scare the dragon off, & (naturally)
the Sun would return.
Ancient Egypt
 Pyramids are thought to have
been aligned with the stars in
Orion Belt to help facilitate the
passage of the ‘Pharaohs’ into
the afterlife.

12. 5
 Used the star Isis (Sirius) to
predict the flooding of the Nile for
planting the crops & keep track of
their year.
 Many temples & structures
built to honour Gods & keep track of
heavenly movements.
Ancient Babylonians
The Babylonians, an ancient Mesopotamian people who flourished
between the Tigris & Euphrates rivers, in the area of modern day
Iraq, were one of the earliest civilizations know to have adopted a
scientific outlook towards the stars & planets.
 Created the first recorded constellations
 Created Zodiac (12 constellations, the Sun
passes through each year)
 Invented degree system used for positions
in the sky
The Mayans
 Built many structures to keep track of solstices & equinoxes.
 Astronomy was an integral part of their culture & day to day
life.

13. 6
 Seriously obsessed with Venus- conducted wars based on the
planet’s position & brightness.
The Ancient Greek
The Ancient Greeks greatly advanced the scientific study of
astronomy by placing an emphasis upon observations and data
collections. Greece was hotbed for astronomical theories &
observations as well as philosophy, mathematics, ethics, drama,
politics & other scholastic pursuits.
 Aristotle (384-322 BC, Greek)
 Proved the earth is sphere using
sailing ships & eclipse shadows
 Geocentric view (the idea that
the Earth lies at the centre of
the universe)
 Aristarchus (310-230 BC, Greek)
 First suggested the Heliocentric model
 Used simple geometry to calculate distance to Sun
from the Earth

14. 7
 Eratosthenes (276-195 BC, Greek)
 Calculated the Earth’s circumference with almost
exact accuracy
 Hipparchus (190-120 BC, Greek)
 Created the first star catalogue
 Calculated the accurate distance
to the Moon
 Invented trigonometry
Islamic Astronomers
During the middle ages, in Western Europe the scientific
development of astronomy stagnated. Most scientists, thinkers and
ordinary people were content to support many of the ideas
propounded by the Greeks, especially as it usually had the firm
backing of the Church, with the result that to question the orthodox
view was considered heresy.
While the advance of astronomy lost momentum in Western
Europe, it accelerated in the Islamic empire which spanned a wide
area & population, from the Middle East, through North Africa and
into Spain. Many of the works by Greek astronomers were translated
into Arabic
Knowledge of astronomy was useful in Islamic rituals, which
interpreted the heavens as a guide to ensure prayers five times a
day, to date religious festivals correctly & also to accurately locate
Mecca.

15. 8
2.2 Ancient Indian Astronomy
Indian astronomy was heavily tied to their religious and spiritual
outlook of the world, but it contained many accurate observations of
phenomena. This acted as a catalyst for the growth of mathematics
in the subcontinent, one of the greatest legacies passed on by India
to the western world.
Ancient India's contributions in the field of astronomy are well
known and well documented. The earliest references to astronomy
are found in the Rig Veda, which are
dated 2000 BC. During next 2500 years,
by 500 AD, ancient Indian astronomy
has emerged as an important part of
Indian studies and its affect is also seen
in several treatises of that period. In
some instances, astronomical principles
were borrowed to explain matters,
pertaining to astrology, like casting of a
horoscope. Apart from this linkage of
astronomy with astrology in ancient
India, science of astronomy continued to develop independently, and
culminated into original findings, like:
 The calculation of occurrences of eclipses
 Determination of Earth's circumference
 Theorizing about the theory of gravitation
 Determining that sun was a star and determination of number
of planets under our solar system
The Jyotish Vedanga, the first Vedic text to mention astronomical
data, records events going back as far as 4000 BC. This period saw
many advances in measuring time and the procession of the
heavens, with a few proto-theories about the structure of the
universe. More importantly, this period saw the transmission of

16. 9
ideas between the Indians, Babylonians, Greeks, and Persians. This
exchange of theories and philosophy was extremely important to the
development of astronomy.
Aryabhata (500 CE)
In this period, a new branch of astronomy, diverging from the Vedas
began. Called the Siddhantic Era, it began with a series of books
called the Siddhanta, which charted the solar year, including
solstices, equinoxes, lunar periods, solar and lunar eclipses, and
planetary movements.
The first properly recorded Siddhantic
astronomy began in the 5th Century CE,
where Indian astronomers such as
Aryabhata began to adopt a more
rigorous, mathematical approach to
astronomy, directing it away from
mysticism and its emphasis on the
calendar. Aryabhata added to the
heliocentric theory, proposing the idea
that the moon reflects the light of the
sun, a theory also proposed by some
Greeks but not widely adopted. He also
proposed that the earth rotated rather than the skies, although this
theory lay undiscovered until the European Renaissance and
Copernicus.
His idea, which included mathematical models about how to
forecast eclipses, eventually found its way into Europe and
influenced Renaissance thought. His book, the ‘Aryabhatia,’ was
translated into Latin in the 13th Century. This work gave the
Europeans some methods for measuring the volume of spheres and
the area of triangles, as well as methods for calculating square roots
and cube roots.

17. 10
Varahmihir (505 CE)
In the 6th Century, Indian astronomers proposed that the same force
holding objects to the Earth also held the celestial bodies in place.
This was an advance upon Anaximander’s idea of equilibrium and the
recognition of a proto-gravitational theory, long before Newton.
Varahamihira proposed that there must be some type of attractive
force keeping objects stationary.
Brahmagupta (591 CE)
The Siddhantic astronomers also understood that the earth was
spherical and attempted to calculate the circumference of the
planet. In the 7th Century CE, the astronomer Brahmagupta arrived
at a figure of 36 000 kilometers for the circumference of the earth,
which is very close to the actual figure.

18. 11
2.3 The Copernican Revolution
The Ancient Greek philosopher, Aristotle, believed that the Earth was
at the centre of the universe & all the bodies in the sky orbited the
Earth. This is known as the ‘Geocentric Theory’.
However upon closer inspections, Aristotle’s idea of ‘perfect circles’
seemed to be flawed. Some planets, Mars in particular, seemed to
switch briefly in retrograde orbits- as if they were temporarily
doubling back upon themselves. Also the brightness of the planets
appeared to vary as they orbited the earth. This all seemed to
contradict Aristotle’s theory.
An answer, proposed by Claudius Ptolemy, was held as truth for
centuries; he continued to advocate a geocentric system, arguing
that the varying brightness & brief retrograde motion were result of
epicycles.
All the theories & discoveries in that era
were made with the background
assumption that the Earth was the
centre of universe. In Western Europe
too, Ptolemaic theory was unchallenged
& backed by the Church as it placed
humanity as the central fact in the
universe. Shortly after Aristotle’s death,
Aristarchus proposed a heliocentric
theory, but this was unpopular at that
times.
Nicolaus Copernicus (1473-1543, Polish)
Copernicus was born in the Renaissance era, which saw an emphasis
placed upon careful, scientific observations is Astronomy. Copernicus
believed that the Ptolemaic system did not properly account for

19. 12
what he observed in the heavens. He
explained the Mars’s retrograde motion as
an optical illusion, caused by the fact that
the Earth is orbiting the Sun faster than
Mars.
Copernicus became the first realize the true
order of the planets in the solar system;
Earth was demoted from the centre of the
universe to the third rock from the Sun. He
published his findings in the book De
Revolutionibus Orbium Coelestium, in 1543, the year of his death.
The Church was not too bothered by such heresy. Copernicus died
before he could be challenged and, moreover, he had asserted that
the planets orbited the Sun in perfect circles. However observational
evidence suggested this was not the case. It fell to another scientist
Johannes Kepler, to make sense of this problem.

20. 13
Johannes Kepler (1571-1630, Germen)
Using the observational data compiled by
Danish astronomer, Tycho Brahe, Kepler first
suggested that the orbits of the planets were
ellipses rather than circles. When Brahe moved
to Prague, Kepler became his assistant. The
men were great rivals, but Brahe’s observations
& Kepler’s theory made for a fruitful
collaboration as Kepler was able to prove the
elliptical orbits of the planets.
Kepler’s laws of planetary motion:
1. The orbit of a planet is an ellipse with the Sun at one of the two foci.
2. A line segment joining a planet and the Sun sweeps out equal areas
during equal intervals of time.
3. The square of the orbital period of a planet is proportional to the cube of
the semi-major axis of its orbit.
Galileo Galilei (1564-1642, Italian)
This new wave of astronomical thinking did
not arouse the interest of the Church until it
reached Italy at the beginning of 17th
century.
Galileo was unwilling to commit to a
heliocentric model until there was sufficient
observational evidence. To gather such
evidence, Galileo pioneered the use of
Telescope in astronomy by advancing the new
Dutch invention for studying the heavens.
Many of the things he saw through his telescope seemed to rule
against the geocentric model. He identified four moons (Ganymeda,
Callisto, Europa & Io) orbiting Jupiter. He also observed the sunspots.

21. 14
Sir Isaac Newton (1643-1727, English)
Although Kepler had described how planets
orbit the sun, he never managed to explain
why they do so in such fashion. That was an
unknown for over half a century until the
English physicist, Isaac Newton, established his
three laws of motion & a law of Universal
Gravitation in his book Principia published in
1678.
Newton’s law of Universal Gravitation:
Every point mass attracts every single other point mass by a force pointing
along the line intersecting both points. The force is proportional to the
product of the two masses and inversely proportional to the square of the
distance between them
Newton’s ideas were groundbreaking. They explained why an apple
fell to the ground as well as why the planets were held in orbits
around the Sun. However Newton’s theory of gravity did not account
for every eventuality. It was unable to explain the perihelion (closest
point to the Sun) shift of Mercury. It was calculated that the
gravitational pull of the sun & other seven known planets was not
sufficient to explain the advancing perihelion of Mercury. The puzzle
was not solved until a young Germen-born physicist, Albert Einstein,
established a new theory of Gravity.

22. 15
Albert Einstein (1879-1955, Germen)
In 1905, while working as a desk clerk for a
Swiss patent office, Einstein published his
‘Special theory of Relativity’. Essentially,
Einstein had proved that, in a vacuum, light
always travels at a constant speed of 300,000
km/s, relative to an observer. His theory also
states that the velocity of light in vacuum is
the fastest speed attainable in the universe.
The special relativity had shown that
distance as well as time was variable.
In General relativity (published in 1915), Einstein adopted the view
that space & time are linked in a four-dimensional unit called
‘spacetime’. General theory of Relativity holds that the mass distorts
spacetime. It is the distortion of the spacetime by mass rather than
the mass itself that is responsible for the gravitational attraction.
Einstein had worked out the mathematics behind General Relativity
& it even accounted for advancing perihelion of Mercury. The
scientific community was understandably sceptical; Einstein needed
a proof that his theory worked in practice. The result of observations
of eclipse of May 1919 showed that the actual position of stars
behind the sun did not match their apparent position. Such an
occurrence could only be explained by General Relativity; the Sun
was distorting the fabric of spacetime & the light from the stars was
being bent. Einstein turned into an overnight celebrity & became the
most prominent scientist of the 20th
century.

23. 16
3. THE SPACE AGE
The Space Age was an entirely new era ushered in by the end of the
Second World War and emerging nuclear power as well as the
beginning of the Cold War. The Space Age began in October of 1957
when the Soviets launched Sputnik 1, the first satellite, into space.
This was when space exploration first became possible. The Space
Age came about as the Soviet Union and the United States started
competing in arms and technology as well as to see which country
would make it into space first. Thus the Space Race between the
Soviets and America was a vital part of the Space Age. About a
month after the Soviets sent Sputnik 1 into space, they sent the
space dog Laika up into orbit in Sputnik 2.
On 12 April 1961, the Soviet Union successfully
put a man in space. Cosmonaut Yuri Gagarin
spent 108 minutes orbiting the Earth once in the
Vostok 1 probe. Less than a month later, On 5
May, Alan Shepard became the first American in
space. It was not until February 1962, that an
American successfully orbited the earth; John
Glenn, aboard Friendship 7 circled the Earth 3
times.
Yuri Gagarin

24. 17
One of the highlights of the Space Age was the Apollo program.
NASA’s Apollo 8 astronauts became the
first men to leave Earth’s gravity & orbit
the Moon. The most famous of
the Apollo aircraft is Apollo 11, which
was the craft carrying Commander Neil
Armstrong and his fellow astronauts
Michael Collins and Buzz Aldrin to the
Moon. On that mission, Armstrong and
Aldrin were the first humans to land and
walk on the Moon. They were later
followed by a number of other
astronauts.
Apollo 11 astronaut Buzz Aldrin
Probes were sent out to study many planets and their satellites,
including the Voyager probes and the Viking probes. These probes
are to thank for much of what we know about some of the other
planets in our Solar System. One recent historic event was the
creation of the Hubble Space Telescope in the early 1990’s. This
enormous project cost $1.5 billion and has allowed scientists to learn
much more about our Solar System as well as others.
Launch of Space Shuttle Discovery Hubble Space Telescope

25. 18
4. THE SOLAR SYSTEM
‘The Solar System’ is the name given to the planetary system of
which the Earth is part. It comprises 8 planets, moons, comets,
meteors, asteroids & dwarf planets which are all held together by
the gravitational pull of a star, named either the Sun or ‘Sol’.
Formation of the solar system:
The formation of the Solar System is estimated to have begun
4.6 billion years ago with the gravitational collapse of a small part of
a giant molecular cloud. Most of the collapsing mass collected in the
centre, forming the Sun, while the rest flattened into a proto
planetary disk out of which the planets, moons, asteroids, and other
small Solar System bodies formed.
The Planets:
The known planets in the solar system can be divided into two
groups. The four planets closest to the sun: Mercury, Venus, Earth &
Mars are called the ‘terrestrial planets’. The outer four planets are
called the ‘gaseous giants’ or ‘Jovian planets’. The terrestrial & Jovian

26. 19
planets are divided by a belt of asteroids between Mars & Jupiter.
Pluto was demoted to the status of ‘Dwarf planet’ giving it home
among similar sized objects & asteroids which make up the Kuiper
Belt.
End of the solar system:
It is difficult to calculate exactly where our solar system ends. It ends
at a point at which objects are no longer affected by the sun’s
gravitational pull. The farthest reaches of the solar system are
thought to be surrounded by a great halo: Oort cloud; home to
millions of comet nuclei & small icy rocks.
Voyager 1 & 2 are the farthest reaching man-made objects in the
solar system. In 2004, Voyager 1 cleared the termination shock, the
area where solar winds begin to slow down & increase in
temperature as they come up against interstellar winds. Voyager
probes will continue transmitting data for several more decades, but
it would take thousands of years for them to reach the nearest star,
Alpha Centauri.

27. 20
4.1 THE SUN:
In the grand scheme of the universe, the sun in just another middle
aged star. Its stellar classification, G2, denoting its yellowish
colouring & its surface temperature (5000°-6000° kelvin) is not
extraordinary either; there are countless G2-type stars.
Fusion:
In the sun, Hydrogen nuclei collide with one another to form Helium
atoms. In this process, called ‘fusion’, mass is transferred into
energy, which is explained by Einstein’s famous equation: 𝐸 = 𝑚𝑐2
.
The period during which sun generates energy through fusion is
called ‘Main sequence’. Our sun is estimated to be 5 billion years old
& its main sequence will last another 5 billion years.
Solar Layers:
The atmosphere of the sun is
composed of several layers, mainly
the photosphere, the chromosphere
and the corona. It's in these outer
layers that the sun's energy, which
has bubbled up from the sun's
interior layers, is detected as
sunlight.
Sunspots:
These are minor regions where the temperature of the photosphere
is cooler than its surroundings. Sunspots are the result of string
localised magnetic field & follow a cycle of 11 years.

28. 21
4.2 MERCURY
Mercury is the smallest and closest to
the Sun of the eight planets in the Solar
System, with an orbital period of about
88 Earth days. Seen from Earth, it
appears to move around its orbit in
about 116 days, which is much faster
than any other planet. It has no
known natural satellites. The planet is
named after the Roman deity Mercury;
the messenger to the gods
Mercury has almost no atmosphere. Its surface is heavily cratered
due to impacts from meteorites.
4.3 VENUS
Venus is the second planet from
the Sun, orbiting it every
224.7 Earth days. It has no natural
satellite. It is named after the Roman
goddess of love and beauty. After
the Moon, it is the brightest natural
object in the night sky, bright enough to
cast shadows. Venus is a terrestrial
planet and is sometimes called Earth's
"sister planet" because of their similar
size, gravity, and bulk composition.
It is the hottest planet in solar system. It rotates on its axis from east
to west. Therefore, on Venus the sun rises in west & sets in east.

29. 22
4.4 EARTH
Earth, also known as Terra, is the
third planet from the Sun,
the densest planet in the solar system,
the largest of the Solar System's for
terrestrial planets, and the only celestial
body to accommodate life. It is home to
millions of species, including billions of
humans.
The Earth takes 365.26 days to orbit the sun & 23.93 hours revolve
once around its axis which is tilted 23.5° to the planet’s orbit.
4.5 THE MOON
The Moon (Latin: Luna) is the Earth's
only natural satellite. Although not the
largest natural satellite in the Solar System,
it is, among the satellites of major planets,
the largest relative to the size of the object
it orbits and, after Jupiter's satellite Io, it is
the second densest satellite among those
whose densities are known.
The Moon is in synchronous rotation with Earth, always showing the
same face with its near side marked by dark volcanic maria that fill
between the bright ancient crustal highlands and the prominent
impact craters . It is the most luminous object in the sky after
the Sun. It takes moon 27.3 days to revolve around earth.

30. 23
4.6 MARS
Mars is the fourth planet from the Sun
and the second smallest planet in the
solar system, after Mercury. Named
after the Roman god of war, it is often
described as the "Red Planet" because
the iron oxide prevalent on its surface
gives it a reddish appearance.
Mars’s atmosphere is consists of 95%
of carbon dioxide & remaining 5% of Argon & Nitrogen. Average
surface temperature is 60° Celsius. Because of this water exist on
mars in frozen & vapour form.
4.7 JUPITER
Jupiter is the fifth planet from the
sun and the largest planet in the solar
system. It is a gas giant with mass one
thousandth of that of the sun but is
two and a half times the mass of all
the other planets in the Solar System
combined.
Jupiter is primarily composed
of hydrogen with a quarter of its mass being helium. There are also
at least 67 moons, including the four large moons called the Galilean
moons that were first discovered by Galileo Galilei in
1610. Ganymede, the largest of these moons, has a diameter greater
than that of the planet Mercury.

31. 24
The Giant Red Spot is its most notable feature. It is a giant storm
which flows anti-clockwise across in area of 24,000 km in length &
12,000 km in width.
4.8 SATURN
Saturn is the sixth planet from the
sun and the second largest planet in
the Solar System, after Jupiter. It is
named after the Roman god of
agriculture. Saturn is gas giant with
an average radius about nine times
that of Earth. While only one-eighth
the average density of Earth, with its
larger volume Saturn is just over 95 times more massive.
One of the greatest fascinations of the solar system is the Rings of
Saturn. They have often earned Saturn the title of the most attractive
planet in solar system.
Titan, Saturn's largest and the Solar System's second largest moon, is
larger than the planet Mercury and is the only moon in the Solar
System to retain a substantial atmosphere.
4.9 URANUS
Uranus is the seventh planet from the Sun. It
has the third-largest planetary radius and
fourth-largest planetary mass in the Solar
System. Uranus is similar in composition
to Neptune, and both are of different
chemical composition to the larger gas
giants Jupiter and Saturn. For this reason,
astronomers sometimes place them in a

32. 25
separate category called "ice giants".
It is the coldest planetary atmosphere in the Solar System, with a
minimum temperature of −224.2 °C and has a complex, layered cloud
structure, with water thought to make up the lowest clouds, and
methane the uppermost layer of clouds. In contrast, the interior of
Uranus is mainly composed of ices and rock.
4.10 NEPTUNE
Neptune is the eighth and farthest
planet from the sun in Solar System.
It is the fourth-largest planet by
diameter and the third-largest by
mass. Among the gaseous planets,
Neptune is the densest. Neptune is
17 times the mass of Earth and is
slightly more massive than its near-
twin Uranus, which is 15 times the
mass of Earth but not as dense.
Neptune orbits the Sun at an average distance of 30.1 astronomical
units. It is named after the Roman god of the sea.
Neptune's atmosphere is notable for its active and visible weather
patterns. For example, at the time of the 1989 Voyager 2 flyby, the
planet's southern hemisphere possessed a Great Dark Spot
comparable to the Great Red Spot on Jupiter.
4.11 PLUTO & THE KUIPER BELT
Discovered in 1930, Pluto was originally classified as the ninth planet
from the Sun. Its status as a major planet fell into question following
further study of it and the outer Solar System over the ensuing 75
years. Starting in 1977 with the discovery of the minor planet 2060

33. 26
Chiron, numerous icy objects similar to Pluto with eccentric orbits
were found. The most notable of these was thes cattered disc
object Eris, discovered in 2005, which
is 27% more massive than Pluto.
Pluto has five known moons:
Charon (the largest, with a diameter
just over half that of Pluto), Nix, Hydra,
Kerberos & Styx.
On July 14, 2015, the Pluto system is
due to be visited by spacecraft for the
first time. The New Horizons probe will
perform a flyby during which it will
attempt to take detailed measurements and images of the plutoid
and its moons.
KUIPER BELT:
Kuiper Belt is a region of the Solar System beyond the planets,
extending from the orbit of Neptune (at 30 AU) to approximately
50 AU from the Sun. It is similar to the asteroid belt, but it is far
larger—20 times as wide and 20 to 200 times as massive. Like the
asteroid belt, it consists mainly of small bodies, or remnants from the
Solar System's formation. Although most asteroids are composed
primarily of rock and metal, most Kuiper belt objects are composed
largely of frozen volatiles (termed "ices"), such as methane,
ammonia & water. The Kuiper belt is home to at least three dwarf
planets: Pluto, Haumea, and Makemake. Some of the Solar System’s
moons, such as Neptune's Triton and Saturn's Phoebe, are also
believed to have originated in the region.

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4.12 MINOR BODIES IN SOLAR SYSTEM
4.12.1 ASTEROIDS
Asteroids are fragments of rock & metal which are greater than 50m
in diameter. On New Year’s Day 1801, the Italian astronomer,
Giuseppe Piazzi, discovered the first asteroid Ceres. Initially he
thought it was a comet, but its orbit was too slow & uniform. Some
scientists suggested it might be a planet between Mars & Jupiter. But
in 1802, second asteroid was discovered, named Pallas. This 2nd
find
led William Herschel, the discoverer of Uranus, to offer a collective
name ‘asteroids’, meaning ‘Star-like’.
Many of the asteroids in the solar system are located in a band
between Mars & Jupiter called the ‘Asteroid Belt’. It is believed that
the belt is failed planet- the chunks of rock & metal were unable to
group together & form 5th
terrestrial planet because of the strong
gravitational pull of Jupiter.
4.12.2 METEOROIDS
Meteoroids can be found throughout the solar system. They are
small fragments of rock & minerals, often the size of a grain of sand.

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Meteoroids are either the chipped away parts of grater bodies or are
remnants from the creation of the solar system.
SHOOTING STAR
When meteoroids collide with the Earth they burn up in the upper
atmosphere, creating a striking spectacle called Meteor.
METEOR SHOWERS

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4.12.3 COMETS
A comet is an icy small Solar System body that, when passing close to
the Sun, heats up and begins to outgas, displaying a visible
atmosphere or coma, and sometimes also a tail. These phenomena
are due to the effects of solar radiation and the solar wind 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 and tail
are much larger and, if sufficiently bright, may be seen from the
Earth without the aid of a telescope. Comets have been observed
and recorded since ancient times by many different cultures. Comets
are known as the ‘dirty snowballs’.
Comets have a wide range of orbital periods, ranging from several
years to several millions of years. Short-period comets originate in
the Kuiper belt or its associated scattered disc, which lie beyond the
orbit of Neptune. Longer-period comets are thought to originate in
the Oort cloud, a spherical cloud of icy bodies extending from
outside of the Kuiper belt to halfway to the next nearest star.

37. 30
5. THE UNIVERSE
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 & energy.
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.
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. 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

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5.1 GALAXIES
In the early 1920s, studies by the renowned American astronomer,
Edwin Hubble, showed that our galaxy, the Milky Way, was not the
only galaxy in the universe. For a long time it had been believed that
the Universe & the Milky Way were one & the same thing, but the
discovery of other galaxies, outside our own, greatly expanded the
size of the known universe.
Galaxies contain varying numbers of planets, star systems, star
clusters, dark matter & interstellar clouds. In between these objects
is a sparse interstellar medium of gas, dust, and cosmic rays.
Supermassive black holes reside at the centre of most galaxies.
Galaxies have been historically categorized according to their
apparent shape, usually referred to as their visual morphology. A
common form is the ‘Elliptical galaxy’ which has an ellipse-shaped
light profile. ‘Spiral Galaxies’ are disk-shaped with dusty, curving
arms. Those with irregular or unusual shapes are known as ‘Irregular
galaxies’.
M110 (Elliptical Galaxy)
NGC 4414 (Spiral Galaxy)
The Bird Galaxy
(Irregular galaxy)

39. 32
THE MILKY WAY
The Milky Way is the name given to our own galaxy, as it is seen from
the Earth, it appears to be a milky-coloured brushstroke sweeping
across the night sky. The fact that this whitish band is actually
millions of stars was not discovered until Galileo become the first
person known to observe the phenomenon through his telescope.
It is impossible to know
exactly what the Milky
Way looks like because
we do not have an
objective viewpoint of
our galaxy. Nevertheless,
observations of other
galaxies, as well as the
subjective view from
Earth & conscientious telescopic studies, have shown the Milky Way
to be a large barred-spiral galaxy.
Origin of our galaxy:
Much remains unknown about the formation of our galaxy; it is
thought that a great cloud of gas collapsed under the weight of its
own gravity between 10 and 15 billion years ago to form the Milky
Way.
Our location in the Milky Way
Our solar system is found on the inner rim of the 0rion arm; a minor
arm found towards the edge of our galaxy. From its position on the
outskirt of the Milky Way, it takes the Solar System 220 million years
to complete one revolution of the core.

40. 33
THE LOCAL GROUP
Most galaxies in our observable universe are moving away from us
as a result of the great explosion which created the Universe, the Big
Bang. This concept has been proved because the stars travelling
away from us emit a longer, redder wavelength. This phenomenon is
known as the ‘red shift’. However the closest galaxies to us emit a
shorter wavelength, which appears bluer on the visible spectrum,
which indicates that they are moving towards us. This occurs
because the force of gravity has overcome
the force of the explosion, a process which
results in the creation of galaxy Clusters
The galaxy cluster to which the Milky Way
belongs is called ‘the Local Group’, which
consists of around thirty galaxies.

41. 34
The Milky Way is the 2nd
largest galaxy in the Local Group, the
largest being Andromeda.
ANDROMEDA
Andromeda is the nearest major galaxy to our Milky Way. It is
approximately 2.5 million light years away, making it the most
distant object we can see through our naked eyes. The Andromeda
galaxy is one of 110 objects visible in the night sky in the northern
hemisphere which were catalogued by French astronomer, Charles
Messier. Catalogued as the 31st
Messier object, Andromeda is often
referred as M31.
The 2006 observations by the Spitzer Space Telescope revealed that
M31 contains one trillion (1012
) stars: at least twice the number of
stars in the Milky Way.
Andromeda is slowly moving toward our Milky Way galaxy. It is
predicted that in about 4 billion years, the two galaxies will collide,
forming an elliptical galaxy.

42. 35
5.2 STARS
A star is a massive, luminous sphere of plasma held together by its
own gravity. The nearest star to Earth is the Sun, which is the source
of most of the planet's energy. Some other stars are visible from
Earth during the night, appearing as a multitude of fixed luminous
points due to their immense distance. Historically, the most
prominent stars were grouped into constellations and asterisms, and
the brightest stars gained proper names. Extensive catalogues of
stars have been assembled by astronomers, which provide
standardized star designations.
STAR FORMATION:
Stars are born within the clouds of dust and scattered throughout
most galaxies. A familiar example of such as a dust cloud is the Orion
Nebula. Turbulence deep within these clouds gives rise to knots with
sufficient mass that the gas and dust can begin to collapse under its
own gravitational attraction. As the
cloud collapses, the material at the
centre begins to heat up. Known as
a protostar, it is this hot core at the
heart of the collapsing cloud that
will one day become a star.
As the cloud collapses, a dense, hot
core forms and begins gathering
dust and gas.
Orion Nebula
Not all of this material ends up as part of a star -the remaining dust
can become planets, asteroids, or comets or may remain as dust.
Once temperature inside the core is hot enough, hydrogen fusion
begins. In this process hydrogen nuclei are fused together to make
helium atoms. In stellar core, this occurs millions of times each
second, generating incredible amount of energy.

43. 36
STELLAR EVOLUTION:
Stellar evolution is the process by which a star undergoes a sequence
of radical changes during its lifetime. Depending on the mass of the
star, this lifetime ranges from only a few million years for the most
massive to trillions of years for the least massive. The table shows
the lifetimes of stars as a function of their masses

44. 37
Supernovas:
A supernova is stellar explosion which is so bright & intense that it is
visible from the Earth. One that appeared in 1572 was said to be as
bright as Venus. A supernova was recorded in 1054 by Chinese
astronomers in the constellation Cassiopeia & its remains can be still
seen today in the form of Crab Nebula.
Black Holes:
If a star undergoing a gravitational collapse is three or more times as
massive as the Sun, gravity is so strong that the collapse is
unstoppable, even the neutrons are crushed. The result is a black
hole. The gravitational force of a black hole is so strong that even
light is not able to escape its gravitational field.
STELLAR CLASSIFICATION
Stellar classification is the classification of stars based on their
spectral characteristics

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5.3 NEBULAE
The term Nebula, meaning ‘mist’ in Latin, was once applied to any
fuzzy patch of light in the night sky. Many of the objects thought to
be nebulae were later discovered to be galaxies outside our own.
However, Messier had catalogued a number of genuine nebulae
including the Crab nebula, which was his Messier Object Number 1.
He also indexed Eagle, Triffid, Omega & Orion nebulae.
Crab Nebula
Nebulae are known to be interstellar clouds of gas & dust within our
own galaxy. This interstellar material is not spread evenly throughout
the galaxy; instead vast areas dense in gas & dust can be found,
having clumped together as a result of gravity. Nebulae are factories
of star formation. Our own planetary system is thought to have
formed from one, The Solar Nebula.
Types of Nebulae
 Emission Nebulae
 Reflection Nebulae
 Dark Nebulae

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HUBBLE SPACE TELESCOPE
The Hubble Space Telescope (HST) is a space telescope that was
launched into low Earth orbit in 1990 and remains in operation. With
a 2.4-meter mirror, Hubble's four main instruments observe in
the near ultraviolet, visible, and near infrared spectra. The telescope
is named after the astronomer Edwin Hubble.
Hubble's orbit outside the distortion of Earth's atmosphere allows it
to take extremely high-resolution images with almost no
background light. Hubble's Deep Field has recorded some of the most
detailed visible-light images ever, allowing a deep view into space
and time. Many Hubble observations have led to breakthroughs
in astrophysics, such as accurately determining the rate of expansion
of the universe.
Eagle Nebula captured by Hubble Space Telescope

47. 40
6. UNSOLVED MYSTERIES
Despite spectacular recent progress, there is still a lot we don't know
about our universe. We don't know why the Big Bang happened. We
don't know what most of the universe is made of. We don't know
whether there is life in space. We don't know how black holes get so
big, or where the first stars have gone. There are still some unsolved
mysteries about our universe.
Let’s start with the biggest question of them all. How did we get
here? How did the universe get started? Why is the universe here at
all?
6.1 THE BIG BANG THEORY
The Big Bang theory is the prevailing cosmological model for the
early development of the universe. The key idea is that the universe
is expanding. Consequently, the universe was denser and hotter in
the past. Moreover, the Big Bang model suggests that at some
moment all matter in the universe was contained in a single point,

48. 41
which is considered the beginning of the universe. Modern
measurements place this moment at approximately 13.8 billion years
ago, which is thus considered the age of the universe. After the initial
expansion, the universe cooled sufficiently to allow the formation
of subatomic particles, including protons, neutrons, and electrons.
Though simple atomic nuclei formed within the first three minutes
after the Big Bang, thousands of years passed before the first
electrically neutral atom formed. The majority of atoms that were
produced by the Big Bang are hydrogen, along with helium and
traces of lithium. Giant clouds of these primordial elements later
coalesced through gravity to form stars and galaxies, and the heavier
elements were synthesized either within stars or during supernovae.
Extrapolation of the expansion of the
universe backwards in time using
general relativity yields an infinite
density and temperature at a finite
time in the past. This ‘singularity’
signals the breakdown of general
relativity. How closely we can
extrapolate towards the singularity is
debated-certainly no closer than the
end of the Planck epoch (from 0 to 10−43
seconds). This singularity is
sometimes called "the Big Bang", but the term can also refer to the
early hot, dense phase itself, which can be considered the "birth" of
our universe. Based on measurements of the expansion using Type a
supernovae, measurements of temperature fluctuations in
the cosmic microwave background, and measurements of
the correlation function of galaxies, the universe has a calculated age
of 13.798 ± 0.037 billion years.

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The Big Bang theory does not provide any explanation for the initial
conditions of the universe; rather, it describes and explains the
general evolution of the universe going forward from that point on.
6.2 DARK MATTER
We actually don’t know what most of the universe is made of.
Astrophysicists hypothesized dark matter because of discrepancies
between the mass of large astronomical objects determined from
their gravitational effects and the mass calculated from the
"luminous matter" they contain. It was first postulated by Jan Oort in
1932

50. 43
Dark matter is a kind of matter hypothesized in astronomy to
account for gravitational effects that appear to be the result of
invisible mass. Dark matter cannot be seen directly with telescopes;
evidently it neither emits nor absorbs light or other electromagnetic
radiation at any significant level. It is otherwise hypothesized to
simply be matter that is not reactant to light. Instead, the existence
and properties of dark matter are inferred from its gravitational
effects on visible matter, radiation, and the large-scale structure of
the universe. According to the Planck mission team, and based on
the standard model of cosmology, the total mass-energy of
the known universe contains 4.9% ordinary matter, 26.8% dark
matter and 68.3% dark energy. Thus, dark matter is estimated to
constitute 84.5% of the total matter in the universe, while dark
energy plus dark matter constitute 95.1% of the total content of the
universe.
DARK ENERGY
In physical cosmology and astronomy, dark energy is a hypothetical
form of energy which permeates all of space and tends to accelerate
the expansion of the universe. Dark energy is the most accepted
hypothesis to explain the observations since the 1990s indicating
that the universe is expanding at an accelerating rate.
High-precision measurements of the expansion of the universe are
required to understand how the expansion rate changes over time.
In general relativity, the evolution of the expansion rate is
parameterized by the equation of state (the relationship between
temperature, pressure, and combined matter, energy, and vacuum
energy density for any region of space). Measuring the equation of
state for dark energy is one of the biggest efforts in observational
cosmology today.

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6.3 QUASARS
Super massive black holes are known as Quasars. Quasars or quasi-
stellar radio sources are the most energetic and distant members of
a class of objects called active galactic nuclei (AGN). Quasars are
extremely luminous and were first identified as being high redshift
sources of electromagnetic energy, including radio waves and visible
light, that appeared to be similar to stars, rather than extended
sources similar to galaxies. Their spectra contain very broad emission
lines, unlike any known from stars, hence the name "quasi-stellar".
Their luminosity can be 100 times greater than that of the Milky Way
Half a century after first getting a bead on quasars, astronomers still
lack a basic understanding of how the most luminous objects in the
universe work.
WORMHOLES
A wormhole, also known as an Einstein-Rosen bridge, is a
hypothetical topological feature of spacetime that would
fundamentally be a "shortcut" through spacetime. A wormhole is
much like a tunnel with two ends each in separate points in
spacetime.

52. 45
Researchers have no observational evidence for wormholes, but the
equations of the theory of general relativity have valid solutions that
contain wormholes.
Wormholes may not only connect two separate regions within the
universe, they could also connect two
different universes. Similarly, some
scientists have conjectured that if one
mouth of a wormhole is moved in a specific
manner, it could allow for time travel.
However, British cosmologist Stephen
Hawking has argued that such use is not
possible.
6.4 END OF THE UNIVERSE
Red shifts have shown that our universe is expanding. But some of
the galaxies closer to the Earth emit blue shift, indicating that they
are moving towards us. The reason these galaxies are moving
towards us is that the gravity is sufficiently strong to overcome the
recession of nearby galaxies.
Some Big Bang theorists have suggested that this blue shift indicates
that the universe will end in a ‘Big Crunch’, when the expansion of
the universe is halted and reversed until all matter in the universe
contracts back into the gravitational singularity from which it came-
at which point time would come to an END.

53. 46
CONCLUSION
Let’s conclude what we have learnt through this report
 What is Astronomy
 How early civilizations observed night sky through naked eyes
 How astronomical theories developed from ancient era, which
formed the basis of our knowledge of heavenly bodies today
 The space age & how it revolutionized the astronomical
thinking
 We learnt about the Solar system, galaxies & our position in the
universe
 How big the universe is in space & times
 Some spectacular cosmic phenomena like Nebulae, Supernovas
& Quasars
 We also had a brief look on some of the unsolved mysteries of
the modern astronomical era.
Now that we have expanded our knowledge about the vast universe
& world beyond Earth, we are ready to look even further.
There are two ways to look at the universe: Philosophical way & the
Physical way. Both ways have their significance in our quest to
understand the universe.
Astronomy can not be learned through theories only, significant
practice & observations are required to completely understand what
lies beyond the boundaries of our world.
Let’s enjoy & continue learning more about what makes our universe
so great!

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BIBLIOGRAPHY
Following books & internet websites were referred while working on
this report.
Books
1) Astronomy by Duncan John
2) A Text Book of General Astronomy by Charles Young
3) Astronomy: Principles and Practice by Roy & Clarke
4) Astronomical Calculations by Mohan Apte
Websites
www.space.com
www.universetoday.com
www.wikipedia.com
www.nasa.gov