2. Sun
• The Sun is one out of billions of stars.
The Sun is the closest star to Earth. The
Sun rotates once every 27 days. The Sun
is now a middle-aged star, meaning it is
at about the middle of its life. The Sun
formed over four and a half billion years
ago. The Sun is only one of over 100
billion stars. In ancient times, the people
believed the Sun was a burning ball of
fire created by the gods. Later, people
thought it was a solid object, or a liquid
ball. Over one million Earths could fit
inside the Sun. Looking directly at the
Sun can permanently damage your eyes
because it is so bright. A star mostly
gives off light and heat. The larger the
star, the hotter its temperature. A super
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giant star can get to be 400 times larger
than our Sun, which is almost a million
miles in diameter.
•
3. Mercury
• Mercury is the closest planet to
the Sun and the eighth largest.
Mercury is smaller in diameter
than Ganymede and Titan but
more massive. In Roman
mythology Mercury is the god of
commerce, travel and thievery,
the Roman counterpart of the
Greek god Hermes, the messenger
of the Gods. The planet probably
received this name because it
moves so quickly across the sky.
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4. Venus
• Venus is named for the ancient Roman goddess of love and beauty.
The planet — the only planet named after a female — may have
been named for the most beautiful deity of her pantheon because
it shone the brightest of the five planets known to ancient
astronomers. Although Venus is not the planet closest to the sun,
its dense atmosphere traps heat in a runaway version of the
greenhouse effect that warms up the Earth. As a result,
temperatures on Venus reach 870 degrees.
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5. Earth
• Our planet is an oasis of life in
an otherwise desolate
universe. The Earth's
temperature, weather,
atmosphere and many other
factors are just right to keep us
alive.
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6. Luna(moon)
• Luna is a beautiful world that
lies some 384,400 kilometers
(almost 239,000 miles) from
Earth. It is littered with
mountains, valleys, old
volcano sites, and many bowl-
like holes called craters. Luna
is a neat world to explore
because you can see it without
a telescope or binoculars. I
know you have seen it. In fact,
you may even see it tonight,
that is because Luna is our
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moon.
7. eclipse
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.The term eclipse is most often used
to describe either a solar eclipse, when the Moon's
shadow crosses the Earth's surface, or a lunar eclipse,
when the Moon moves into the Earth's shadow.
However, it can also refer to such events beyond the
Earth-Moon system: for example, a planet moving into
the shadow cast by one of its moons, a moon passing
into the shadow cast by its host planet, or a moon
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passing into the shadow of another moon. A binary star
system can also produce eclipses if the plane of the
orbit of its constituent stars intersects the observer's
position.
8. Mars
Mars (Greek: Ares) is the god of War.
The planet probably got this name
due to its red color. Mars is
sometimes referred to as the Red
Planet.e first spacecraft to visit
Mars was Mariner 4 in 1965.
Several others followed including
Mars 2, the first spacecraft to land
on Mars and the two Viking landers
in 1976. Ending a long 20 year
hiatus, Mars Pathfinder landed
successfully on Mars on 1997 July
4. In 2004 the Mars Expedition
Rovers "Spirit" and "Opportunity"
landed on Mars sending back
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geologic data and many pictures;
they are still operating after more
than three years on Mars. In 2008,
Phoenix landed in the northern
plains to search for water.
9. Jupiter
The planet's swirling cloud stripes are
punctuated by massive storms such as
the Great Red Spot, which has raged for
hundreds of years.Jupiter is the fourth
brightest object in the sky (after the
Sun, the Moon and Venus). It has been
known since prehistoric times as a
bright "wandering star". But in 1610
when Galileo first pointed a telescope
at the sky he discovered Jupiter's four
large moons Io, Europa, Ganymede and
Callisto (now known as the Galilean
moons) and recorded their motions
back and forth around Jupiter.Jupiter is
about 90% hydrogen and 10% helium
(by numbers of atoms, 75/25% by
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mass) with traces of methane, water,
ammonia and "rock". Jupiter probably
has a core of rocky material amounting
to something like 10 to 15 Earth-
masses.
10. Jupiter
Jupiter has 63 known satellites (as of Feb 2004): the four large Galilean moons plus
many more small ones some of which have not yet been named. Jupiter radiates
more energy into space than it receives from the Sun. The interior of Jupiter is hot:
the core is probably about 20,000 K. The heat is generated by the Kelvin-Helmholtz
mechanism, the slow gravitational compression of the planet. (Jupiter does NOT
produce energy by nuclear fusion as in the Sun; it is much too small and hence its
interior is too cool to ignite nuclear reactions.)Jupiter is the fourth brightest object in
the sky (after the Sun, the Moon and Venus). It has been known since prehistoric
times as a bright "wandering star". But in 1610 when Galileo first pointed a telescope
at the sky he discovered Jupiter's four large moons Io, Europa, Ganymede and
Callisto (now known as the Galilean moons) and recorded their motions back and
forth around Jupiter.The red spot, a 40,000 km storm system, has been raging for
over 300 years.
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11. Saturn
In Roman mythology, Saturn is the
god of agriculture. The associated
Greek god, Cronus, was the son of
Uranus and Gaia and the father of
Zeus (Jupiter). Saturn is the root of
the English word "Saturday”.Like
Jupiter, Saturn is about 75%
hydrogen and 25% helium with
traces of water, methane,
ammonia and "rock", similar to the
composition of the primordial Solar
Nebula from which the solar
system was formed.
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Saturn's interior is similar to Jupiter's
consisting of a rocky core, a liquid
metallic hydrogen layer and a
molecular hydrogen layer. Traces
of various ices are also present.
12. Uranus
us, the first planet discovered in modern
times, was discovered by William
Herschel while systematically searching
the sky with his telescope on March 13,
1781. It had actually been seen many
times before but ignored as simply
another star (the earliest recorded
sighting was in 1690 when John
Flamsteed cataloged it as 34 Tauri).
Herschel named it "the Georgium
Sidus" (the Georgian Planet) in honor of
his patron, the infamous (to Americans)
King George III of England; others called
it "Herschel". The name "Uranus" was
first proposed by Bode in conformity
with the other planetary names from
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classical mythology but didn't come
into common use until 1850.
Uranus has been visited by only one
spacecraft, Voyager 2 on Jan 24 1986.
13. Neptune
In Roman mythology Neptune (Greek: Poseidon) was the god of the Sea.Neptune has
been visited by only one spacecraft, Voyager 2 on Aug 25 1989. Much of we know
about Neptune comes from this single encounter. But fortunately, recent ground-
based and HST observations have added a great deal, too.Neptune's composition is
probably similar to Uranus': various "ices" and rock with about 15% hydrogen and a
little helium. Like Uranus, but unlike Jupiter and Saturn, it may not have a distinct
internal layering but rather to be more or less uniform in composition. But there is
most likely a small core (about the mass of the Earth) of rocky material. Its
atmosphere is mostly hydrogen and helium with a small amount of methane.
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14. Pluto
In Roman mythology, Pluto (Greek: Hades) is the god of the underworld. The
planet received this name (after many other suggestions) perhaps because
it's so far from the Sun that it is in perpetual darkness and perhaps
because "PL" are the initials of Percival Lowell.
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Pluto was discovered in 1930 by a fortunate accident. Calculations which later
turned out to be in error had predicted a planet beyond Neptune, based on
the motions of Uranus and Neptune. Not knowing of the error, Clyde W.
Tombaugh at Lowell Observatory in Arizona did a very careful sky survey
which turned up Pluto anyway.
15. Big Bang
• According to the theories of physics, if we were to look at the Universe one
second after the Big Bang, what we would see is a 10-billion degree sea of
neutrons, protons, electrons, anti-electrons (positrons), photons, and
neutrinos. Then, as time went on, we would see the Universe cool, the
neutrons either decaying into protons and electrons or combining with
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protons to make deuterium (an isotope of hydrogen). As it continued to
cool, it would eventually reach the temperature where electrons combined
with nuclei to form neutral atoms. Before this "recombination" occurred,
the Universe would have been opaque because the free electrons would
have caused light (photons) to scatter the way sunlight scatters from the
water droplets in clouds.
16. Black hole
A black hole is a region of spacetime
whose gravitational field is so strong
that nothing which enters it, not even
light, can escape. Around a black hole
there is a mathematically defined
surface called an event horizon that
marks the point of no return. It is called
"black" because it absorbs all the light
that hits the horizon, reflecting nothing,
just like a perfect black body in
thermodynamics.Objects whose gravity
field is too strong for light to escape
were first considered in the 18th
century by John Michell and Pierre-
Simon Laplace. The first modern
solution of general relativity that would
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characterize a black hole was found by
Karl Schwarzschild in 1916, although its
interpretation as a region of space from
which nothing can escape was not fully
appreciated for another four decades.
17. Black hole
Long considered a mathematical The core of the star collapses and becomes
super dense where even the atomic
curiosity, it was during the nuclei are squeezed together.The
1960s that theoretical work energy density at the core goes to
showed black holes were a infinity. After a black hole has formed it
generic prediction of general can continue to grow by absorbing
mass from its surroundings. By
relativity. The discovery of absorbing other stars and merging with
neutron stars sparked interest other black holes, super massive black
in gravitationally collapsed holes of millions of solar masses may
form.There is general consensus that
compact objects as a possible supermassive black holes exist in the
astrophysical reality.Black holes centers of most galaxies. In particular,
of stellar mass are expected to there is strong evidence of a black hole
form when a star of more than of more than 4 million solar masses at
the center of our galaxy, the Milky Way.
5 solar masses runs out of
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energy fuel. This results in the
outer layers of gas being
thrown out in a supernova
explosion.
18. Neutron star
A neutron star is a type of stellar
remnant that can result from the
gravitational collapse of a massive
star during a Type II, Type Ib or
Type Ic supernova event. Such
stars are composed almost entirely
of neutrons, which are subatomic
particles without electrical charge
and with slightly larger mass than
protons. Neutron stars are very hot
and are supported against further
collapse by quantum degeneracy
pressure due to the Pauli exclusion
principle. This principle states that
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no two neutrons (or any other
fermionic particles) can occupy the
same place and quantum state
simultaneously.
19. Supernova
Early work on what was originally believed to be
simply a new category of novae was performed
during the 1930s by Walter Baade and Fritz
Zwicky at Mount Wilson Observatory.[25] The
name super-novae was first used during 1931
lectures held at Caltech by Baade and Zwicky,
then used publicly in 1933 at a meeting of the
American Physical Society.[4] By 1938, the
hyphen had been lost and the modern name was
in use.[26] Because supernovae are relatively
rare events within a galaxy, occurring about once
every 50 years in the Milky Way,[6] obtaining a
good sample of supernovae to study requires
regular monitoring of many galaxies.
Supernovae in other galaxies cannot be predicted
with any meaningful accuracy. Normally, when
they are discovered, they are already in
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progress.[27] Most scientific interest in
supernovae—as standard candles for measuring
distance, for example—require an observation of
their peak luminosity. It is therefore important to
discover them well before they reach their
maximum.
20. Nebula
astronomers believe that nebulae are
made from the huge collapse of
gas in what they refer to as the
Interstellar Medium (the gas, dust
and cosmic rays that can be found
between planets and stars in
galaxies). As the material falls in
on itself under its own weight,
large stars are made in the centre.
When this happens, ultraviolet
radiation shoots out like a laser
beam and the nebula is lit up - just
like a Christmas tree.
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21. Eagle Nebula
Baby stars hatch from eggs
(Evaporating Gaseous
Globules) the finger-like
tips emerging from this
pillar of gas in the eagle
Nebula.This picture was
taken by the Hubble
Space telescope.
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25. A newborn star
When a temperature of about 27,000,000°F is reached,
nuclear fusion begins. This is the nuclear reaction in
which hydrogen atoms are converted to helium atoms
plus energy. This energy (radiation) production prevents
further contraction of the star.
Young stars emit jets of intense radiation that heat the
surrounding matter to the point at which it glows
brightly. These narrowly-focused jets can be trillions of
miles long and can travel at 500,000 miles per hour.
These jets may be focused by the star's magnetic field.
The protostar is now a stable main sequence star which
will remain in this state for about 10 billion years. After
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that, the hydrogen fuel is depleted and the star
begins to die.
26. Star death
• A star with a mass much greater than that of
the sun will form, live, and die more quickly
than a main sequence star. The reason for
this is its greater mass, for the resulting
gravity squeezes the star's core and creates
greater pressures, resulting in a faster fusion
rate.After about 10 to 15 million years
(versus over 10 billion for a main sequence
star), a supergiant's core has turned to
carbon and has swollen into a red supergiant
(Betelgeuse, a bright star forming the
constellation Orion's shoulder, is an example
of a star in this stage). The reason it glows
red is that since its outer layers have
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expanded, it has a much greater volume to
heat, yet is only producing the same amount
of energy. Thus, it is naturally cooler, and
glows red.
27. Star life span
The most massive stars have the shortest
lives. Stars that are 25 to 50 times that of
the Sun live for only a few million years.
Stars like our Sun live for about 10 billion
years. Stars less massive than the Sun
have even longer life spans.
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28. The Pin Wheel Galaxy
The Pinwheel Galaxy (also known as Messier 101 or
NGC 5457) is a face-on spiral galaxy distanced 21
million light-years (six megaparsecs)[2] away in the
constellation Ursa Major, first discovered by Pierre
Méchain on March 27, 1781, and communicated to
Charles Messier who verified its position for inclusion in
the Messier Catalogue as one of its final entries.On
February 28, 2006, NASA and the ESA released a very
detailed image of the Pinwheel Galaxy, which was the
largest and most detailed image of a galaxy by
Hubble Space Telescope at the time.[7] The image was
composed from 51 individual exposures, plus some
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extra ground-based photos.On August 24, 2011, a Type
Ia supernova, SN 2011fe, was discovered in M101
