About universe and solar system

1. Earth and Life Science

3. The Universe is all of time and space and its
contents. It includes planets, moons, minor
planets, stars, galaxies, the contents
of intergalactic space, and all matter and
energy.The observable universe is about
28 billion parsecs (91 billion light-years) in
diameter.The size of the entire Universe is
unknown, but there are many hypotheses
about the composition and evolution of the
Universe.

4.  The Big Bang theory is the
prevailing cosmological model for
the universe from the earliest known
periods through its subsequent large-scale
evolution.
 Detailed measurements of the expansion rate
of the universe place this moment at
approximately 13.8 billion years ago, which is
thus considered the age of the universe.

5.  The Big Bang did not occur as an explosion in the
usual way one think about such things, despite
one might gather from its name.The universe
did not expand into space, as space did not exist
before the universe, according to NASA. Instead,
it is better to think of the Big Bang as the
simultaneous appearance of space everywhere
in the universe.The universe has not expanded
from any one spot since the Big Bang — rather,
space itself has been stretching, and carrying
matter with it.

6.  After the initial expansion, the universe
cooled sufficiently to allow the formation
of subatomic particles, and later
simple atoms. Giant clouds of these
primordial elements later coalesced
through gravity in halos of dark matter,
eventually forming
the stars and galaxies visible today.

7.  Georges Henri Joseph Édouard
Lemaître was a
Belgian priest, astronomer and professor
of physics at the Catholic University of
Leuven.
 He proposed the Big BangTheory

8.  Creationism is the religious belief that
the universe and life originated "from specific
acts of divine creation”, as opposed to the
scientific conclusion that they came about
through natural processes.
 Creationists base their beliefs on a literal
reading of religious texts, including the
biblicalGenesis creation myth and Islamic
mythology from the Quran.

9.  Intelligent Design is
the pseudoscientific view that "certain
features of the universe and of living things
are best explained by an intelligent cause, not
an undirected process such as natural
selection."

10.  The Steady StateTheory is an alternative to
the Big Bang model of the evolution of the
universe. In the steady-state theory, the
density of matter in the expanding
universe remains unchanged due to a
continuous creation of matter.

11.  The 'holographic principle,' the idea that a
universe with gravity can be described by a
quantum field theory in fewer dimensions,
has been used for years as a mathematical
tool in strange curved spaces. New results
suggest that the holographic principle also
holds in flat spaces. Our own universe could
in fact be two dimensional and only appear
three dimensional -- just like a hologram.

12.  According to NASA, the gravitational pull of
small fluctuations in the density of matter back
then gave rise to the vast web-like structure of
stars and emptiness seen today. Dense regions
pulled in more and more matter through gravity,
and the more massive they became, the more
matter they could pull in through gravity,
forming stars, galaxies and larger structures
known as clusters, super clusters, filaments and
walls, with "great walls" of thousands of galaxies
reaching more than a billion light years in
length.

13.  Less dense regions did not grow, evolving
into area of seemingly empty space called
voids.

14.  Atoms only make up 4.6% of the universe. Of
the remainder, 23% is made up of dark
matter, which is likely composed of one or
more species of subatomic particles that
interact very weakly with ordinary matter,
and 72% is made of dark energy, which
apparently is driving the accelerating
expansion of the universe.

15.  In the 1920s, astronomer Edwin
Hubble discovered the universe was not
static. Rather, it was expanding, a find that
revealed the universe was apparently born in
a Big Bang.

16.  After that, it was long thought the gravity of matter in
the universe was certain to slow the expansion of the
universe.Then, in 1998, the Hubble SpaceTelescope's
observations of very distant supernovae revealed that
a long time ago, the universe was expanding more
slowly than it is today. In other words, the expansion
of the universe was not slowing due to gravity, but
instead inexplicably was accelerating.The name for
the unknown force driving this accelerating expansion
is dark energy, and it remains one of the greatest
mysteries in science.

18. A solar system is a star and all of the objects
that travel around it — planets, moons,
asteroids, and meteoroids. Most stars host
their own planets, so there are likely tens of
billions of other solar systems in the Milky
Way galaxy alone.

19. The solar system we call home is located in an
outer spiral arm of the vast MilkyWay galaxy.
It consists of the sun (our star) and everything
that orbits around it.This includes the eight
planets and their natural satellites (such as
our moon), dwarf planets and their satellites,
as well as asteroids, comets and countless
particles of smaller debris.

20. The solar system extends much farther than
the eight planets that orbit the sun.The solar
system also includes the Kuiper Belt that lies
past Neptune’s orbit. And beyond the fringes
of the Kuiper Belt is the Oort Cloud.

21. The Oort Cloud is a giant spherical shell that
surrounds our solar system. It has never been
directly observed, but its existence is
predicted based on mathematical models and
observations of comets that likely originate
there. It is made of icy pieces of space debris
the sizes of mountains and sometimes larger,
orbiting our sun as far as 1.6 light years away.

22. Our solar system formed about 4.5 billion years
ago from a dense cloud of interstellar gas and
dust.The cloud collapsed, possibly due to the
shockwave of a nearby exploding star, called
a supernova.When this dust cloud collapsed,
it formed a solar nebula — a spinning, swirling
disk of material.

23. At the center, gravity pulled more and more
material in. Eventually the pressure in the
core was so great that hydrogen atoms
began to combine and form helium, releasing
a tremendous amount of energy.With that,
our sun was born, and it eventually amassed
more than 99 percent of the available matter.

24. The order and arrangement of the planets and
other bodies in our solar system is due to the
way the solar system formed. Nearest the
sun, only rocky material could withstand the
heat when the solar system was young. For
this reason, the first four planets — Mercury,
Venus, Earth and Mars — are terrestrial
planets.They're small with solid, rocky
surfaces.

25. Meanwhile, materials we are used to seeing as
ice, liquid or gas settled in the outer regions
of the young solar system. Gravity pulled
these materials together, and that is where
we find gas giants Jupiter and Saturn and ice
giants Uranus and Neptune.

27.  The sun at the heart of our solar system is a
yellow dwarf star, a hot ball of glowing gases.
Its gravity holds the solar system together,
keeping everything from the biggest planets
to the smallest particles of debris in its orbit.
 With the radius of 432,168.6 miles, our sun is
not an especially large star compared to the
many other stars.
 Its distance from Earth is 93 million miles.

29.  Mercury's eccentric orbit takes the small planet as close as 47
million km (29 million miles) and as far as 70 million km (43 million
miles) from the sun.Temperatures on Mercury's surface can reach
800 degrees Fahrenheit (430 degrees Celsius). Because the planet
has no atmosphere to retain that heat, night time temperatures on
the surface can drop to -290 degrees Fahrenheit (-180 degrees
Celsius).
 Mercury speeds around the sun every 88 days, travelling through
space at nearly 50 km (31 miles) per second, faster than any other
planet. One Mercury solar day (one day-night cycle) equals 175.97
Earth days.
 Mercury's surface resembles that of Earth's Moon, scarred by many
impact craters resulting from collisions with meteoroids and
comets.

31.  Venus is the second planet from the sun and our closest
planetary neighbor.
 With a radius of 3,760 miles (6,052 kilometers),Venus is
roughly the same size as Earth, just slightly smaller. From an
average distance of 67 million miles (108 million kilometers),
Venus is 0.7 astronomical units away from the sun. One
astronomical unit (abbreviated as AU), is the distance from
the sun to Earth. From this distance, it takes sunlight 6
minutes to travel from the sun toVenus.
 Venus makes a complete orbit around the sun (a year in
Venusian time) in 225 Earth days or slightly less than two
Venusian day-night cycles.

33.  Earth is the third planet from the sun and the fifth largest in
the solar system. Just slightly larger than nearbyVenus,
Earth is the biggest of the terrestrial planets. Our home
planet is the only planet in our solar system known to harbor
living things.
 With a radius of 3,959 miles (6,371 kilometers), Earth is the
biggest of the terrestrial planets, and the fifth largest planet
overall.

35.  Mars is a rocky body about half the size of Earth. As with the
other terrestrial planets - Mercury,Venus, and Earth -
volcanoes, impact craters, crustal movement, and
atmospheric conditions such as dust storms have altered the
surface of Mars.
 Mars has two small moons, Phobos and Deimos, that may be
captured asteroids. Potato-shaped, they have too little mass
for gravity to make them spherical. Phobos, the innermost
moon, is heavily cratered, with deep grooves on its surface.

37.  Jupiter's stripes and swirls are cold, windy clouds of
ammonia and water.The atmosphere is mostly hydrogen
and helium, and its iconic Great Red Spot is a giant storm
bigger than Earth that has raged for hundreds of years.
 With a radius of 43,440.7 miles (69,911 kilometers), Jupiter is
11 times wider than Earth. If Earth were the size of a nickel,
Jupiter would be about as big as a basketball.
 Jupiter has the shortest day in the solar system. One day on
Jupiter takes only about 10 hours (the time it takes for
Jupiter to rotate or spin around once), and Jupiter makes a
complete orbit around the sun (a year in Jovian time) in
about 12 Earth years (4,333 Earth days).

39.  Like Jupiter, Saturn is made mostly of hydrogen and helium. Its
volume is 755 times greater than that of Earth.
 In the early 1980s, NASA's twoVoyager spacecraft revealed
that Saturn's rings are made mostly of water ice, and they
imaged "braided" rings, ringlets, and "spokes" - dark features in
the rings that form and initially circle the planet at different
rates from that of the surrounding ring material. Saturn's ring
system extends hundreds of thousands of kilometers from the
planet, yet the vertical height is typically about 10 meters
 NASA has discovered 53 confirmed moons and another 9
provisional moons (for a possible total of 62 moons). (30 feet) in
the main rings.

41.  The seventh planet from the sun with the third largest
diameter in our solar system, Uranus is very cold and windy.
The ice giant is surrounded by 13 faint rings and 27 small
moons as it rotates at a nearly 90-degree angle from the
plane of its orbit.This unique tilt makes Uranus appear to
spin on its side, orbiting the sun like a rolling ball.
 The first planet found with the aid of a telescope, Uranus was
discovered in 1781 by astronomerWilliam Herschel, although
he originally thought it was either a comet or a star. It was
two years later that the object was universally accepted as a
new planet, in part because of observations by astronomer
Johann Elert Bode.

42.  With a radius of 15,759.2 miles (25,362 kilometers), Uranus is
4 times wider than Earth. If Earth was the size of a nickel,
Uranus would be about as big as a softball.
 One day on Uranus takes about 17 hours (the time it takes for
Uranus to rotate or spin once). And Uranus makes a
complete orbit around the sun (a year in Uranian time) in
about 84 Earth years (30,687 Earth days).
 From an average distance of 1.8 billion miles (2.9 billion
kilometers), Uranus is 19.8 astronomical units away from the
sun.
 From this distance, it takes sunlight 2 hours and 40 minutes
to travel from the sun to Uranus.

44.  The ice giant Neptune was the first planet located through
mathematical predictions rather than through regular
observations of the sky.
 Nearly 4.5 billion kilometers (2.8 billion miles) from the Sun,
Neptune orbits the Sun once every 165 years. It is invisible to
the naked eye because of its extreme distance from Earth.
 Neptune has 13 known moons, six of which were discovered
byVoyager 2.
 Neptune has six known rings.Voyager 2's observations
confirmed that these unusual rings are not uniform but have
four thick regions (clumps of dust) called arcs.The rings are
thought to be relatively young and short-lived.

45. Besides those planets, we still have more
objects that can be seen in our solar system
like small bodies such as the Dwarf Planets,
Pluto, Ceres, Asteroids, Comets, and Meteors
and Meteorites.We also have the moons of
different planets and the regions such as the
Kupier Belt and the Oort Cloud.

46. TRIVIAS

48.  The biggest/largest known stars in the
Universe.
 VY Canis Majoris (VY Cma) is a red hypergiant
star located in the constellation Canis Major.
 With as size of 2600 radii, it is the largest known
star and also one of the most luminous known.
 If you can fit 1 million planet Earths in into our
sun.You can fit 1 billion Suns into VY Canis
Majoris.

50.  The smallest known star right now is the OGLE-
TR-122b, a red dwarf star that’s part of a binary
stellar system.
 It is the smallest star to ever have its radius
accurately measured; 0.12 solar radii.This
works out to be 167,000 km, which is only 20%
larger than Jupiter.

51. END