Interesting facts about earth and world
1.)
The brightest astronomical event in historic times was the supernova of 1054, which produced the Crab Nebula. The supernova was far brighter than Venus. It was bright enough to be visible in daylight and to cast a shadow at night. We know of it through the astronomical records of China, Japan, and the Middle East.
2.)
Since the invention of the telescope, no supernovae have been observed within our galaxy. Supernovae were recorded in 1572 and 1604, while Hans Lippershey invented the telescope in 1608 and Galileo was the first to turn his telescope skyward in 1609
3.)
The telescope was invented in 1608 when spectacle-maker Hans Lippershey's apprentice was playing games. The apprentice was amusing himself with lenses and found a combination that made things seem closer. When Lippershey was shown this combination, he enclosed the lenses at two ends of a tube.
4.)
The philosopher Immanuel Kant (1724–1804) was the first person to propose that what we now call galaxies lay outside the Milky Way and were indeed galaxies (or "island universes", as Kant called them) in their own right
5.) As late as 1820, the universe was thought by European scientists to be 6,000 years old. It is now thought to be about 13,700,000,000 years old.
6.)
The Earth is rotating on its axis at a rate of 460 metresper second at the equator, and is orbiting the sun at a rate of about 30 kilometres per second. The sun is orbiting the centre of the Milky Way at a rate of about 220 kilometres per second. The Milky Way is moving at a speed of about 1000 kilometres per second towards a region of space 150 million light years away called the Great Attractor
7.)
It is possible that many planets in the galaxy may not orbit around stars. Recent work by Kailash Sahu found six gravitational lenses in the star cluster M22 from objects smaller than brown dwarfs, the smallest type of star. Only one gravitational lensing event by a star was found in the same work.
8.)
The Large Zenith Telescope (LZT), located near Vancouver, has a mirror made out of mercury. The telescope features 28 liter’s of mercury in a pan which spins, causing the mercury to assume a parabolic shape. The telescope only cost $500,000, about 1/100th as much as a similarly-sized telescope with a glass mirror would cost. Its main disadvantage is that it can only look straight up - otherwise the poisonous mercury would spill.
9.)
A "light year" is a measure of distance, not time. It is defined as the distance light travels in one year. Light moves at a velocity of about 300,000 kilometres each second, so in one year, it travels about 9,500,000,000,000 kilometres
10.)
While astronomers used to believe that galaxies were distributed more or less evenly through space, they have now found regions where galaxies are rare or absent. The largest of these regions is located in the direction of the constellation Bootes, and measures more than 300 million light years across.
11.)
The matter in the universe is so thinly dispersed that the universe can be compared with a building twenty miles long, twenty miles wide, and twenty miles high, containing only a single grain of sand.
12.)
The term "Big Bang" started as a putdown. In the 1940's, there were many competing theories about the nature of the universe. British astrophysicist Fred Hoyle coined the term "Big Bang" as a snide putdown of his competitors, only to have the term find its way into the general consciousness as the description of the correct theory
13.)
A massive star has a shorter lifetime than a less massive star. The more massive a star, the more tightly its gravity pulls it together, the hotter it must be to keep it from collapsing, and the more rapidly it uses up its hydrogen fuel. The reason there are so few really massive stars is that they do not live very long, as little as a million years. For comparison, our sun has an expected lifetime of about 11,000 million years.
14.)
Physicists believe that our universe does not have three dimensions or four dimensions, but eleven dimensions (ten of space and one of time). We do not observe the extra spatial dimensions because they are curled tightly around each other.
15.)
It is not possible to hear in space. Because there is no atmosphere in space to conduct the sound, it would not carry. So, the object would make a noise, but it would not carry to any receiver, and no one would hear it
16.)
About 25% of the universe consists of "dark matter", and about 70% consists of "dark energy", leaving only about 5% of the universe visible to us.
17.)
The word arctic is derived from the ancient Greek word for bear, arktos. The reason is that the constellation of Ursa Major, the Great Bear, lies in the northern sky.
18.)
There is a giant supercluster of galaxies in the directionof the constellations Perseus and Pegasus that is over a thousand million light-years long, and is the largest supercluster known. In 1989, astronomers found another structure that they dubbed the "Great Wall". It is a collection of galaxies some 500 million light-years long, 200 million light-years wide and 15 million light-years thick.
19.)
There are an estimated 50 thousand million galaxies in the universe, with the typical galaxy containing 50 thousand million to 100 thousand million stars. It is estimated that there are 1022 stars in total in the universe.
20.)
The star Betelgeuse, a bright star in the constellation of Orion, is estimated to have a diameter of around 700 million miles. If it were placed at the centre of our solar system, it would extend beyond the orbit of Jupiter.
21.)
Alpha Centauri, one of the stars in the system closest to the sun, is never visible in the sky north of about 30°Northern Latitude. Though it is the third-brightest star in the sky, it was not seen by the ancient Greeks or the chief observatories of the mediaeval Arabs at Cordoba, Baghdad, and Damascus, all located north of the 30° line.
22.)
Information about what has fallen into a black hole is stored on the black hole's event horizon. Recent calculations by those who study quantum gravity theory and superstrings have confirmed what Stephen Hawking and his collaborators proposed a decade or more ago. Evidently, the information contained in matter that falls into a black hole is by some curious means encoded in the pattern of frozen quantum fields at the horizon. This raises some interesting possibilities that we could resurrect clocks, humans, spacecraft, and whole planets into something like their pristine form if we could magically reverse the in-fall and collapse process. Many believe that this mathematical result means that we have reached a watershed moment in history in understanding the connection between quantum mechanics and gravitation theory. Quantum mechanics deals with statements about the information that we can extract about a quantum mechanical process involving observation. Now this same information language can be applied to configurations of the gravitational field and space-time itself
23.)
For black holes, distant observers will see only the outside of the event horizon, while individual observers falling into the black hole will experience quite another "reality." General relativity predicts that for distant observers outside the horizon, they will experience the three space-like coordinates and one time-like coordinate, as they always have. For someone falling into a black hole and crossing the horizon, this crossing is mathematically predicted to involve the transformation of your single time-like coordinate into a space-like coordinate, and your three space-like coordinates into three time-like coordinates. Along any of these three former space-like coordinates, they now all terminate on the singularity; you're experiencing them as time-like now. All choices always terminate on the singularity—at least in the case of a non-rotating black hole. The coordinate which used to measure external time now has a space-like character which affords you some wiggle room, but dynamically, in terms of these new reversed space and time coordinates, you find that no stable orbits about the singularity are possible no matter what you try to do. Without any stable orbits, and the inexorable freefall into the singularity, relativists often refer to this as the collapse of space-time geometry.
24.)
There is sound in space. Sound is a pressure wave, and as long as there is some kind of gaseous medium, there is the possibility of forming pressure waves in it. In space, the interplanetary medium is a very dilute gas at a density of about 10 atoms per cubic centimeter, and the speed of sound in this medium is about 300 kilometers per second. Typical disturbances due to solar storms and "magneto-sonic turbulence" at the Earth's magnetopause have scales of hundreds of kilometers, so the acoustic wavelengths are enormous. Human ears would never hear them, but we can technologically detect these pressure changes and play them back for our ears to hear by electronically compressing them.
25.)
Saturn's moon Titan has plenty of evidence of organic (life) chemicals in its atmosphere.
26.)
Life is known to exist only on Earth, but in 1986 NASA found what they thought might be fossils of microscopic living things in a rock from Mars.
27.)
Most scientists say life's basic chemicals formed on the Earth. The astronomer Fred Hoyle said they came from space.
28.)
Oxygen is circulated around the helmet in space suits in order to prevent the visor from misting.
29.)
The middle layers of space suits are blown up like a balloon to press against the astronaut's body. Without this pressure, the astronaut's body would boil!
30.)
The gloves included in the space suit have silicon rubber fingertips which allow the astronaut some sense of touch.
31.)
The full cost of a spacesuit is about $11 million although 70% of this is for the backpack and the control module.
32.)
Ever wondered how the pull of gravity is calculated between heavenly bodies? It's simple. Just multiply their masses together, and then divide the total by the square of the distance between them.
33.)
Glowing nebulae are named so because they give off a dim, red light, as the hydrogen gas in them is heated by radiation from the nearby stars.
34.)
The Drake Equation was proposed by astronomer Frank Drake to work out how many civilizations there could be in our galaxy - and the figure is in millions.
35.)
SETI is the Search for Extra-terrestrial Intelligence - the program that analyzes radio signals from space for signs of intelligent life.
36.)
The Milky Way galaxy we live in: is one among the BILLIONS in space.
37.)
The Milky Way galaxy is whirling rapidly, spinning our sun and all its other stars at around 100 million km per hour.
38.)
The Sun travels around the galaxy once every 200 million years – a journey of 100,000 light years.
39.)
There may be a huge black hole in the very middle of the most of the galaxies.
40.)
The Universe is probably about 15 billion years old, but the estimations vary
41.)
One problem with working out the age of the Universe is that there are stars in our galaxy which are thought to be 14 to 18 billion years old – older than the estimated age of the Universe. So, either the stars must be younger, or the Universe older.
42.)
The very furthest galaxies are spreading away from us at more than 90% of the speed of light.
43.)
The Universe was once thought to be everything that could ever exist, but recent theories about inflation (e.g. Big Bang) suggest our universe may be just one of countless bubbles of space time.
44.)
The Universe may have neither a centre nor an edge, because according to Einstein’s theory of relativity, gravity bends all of space time around into an endless curve.
45.)
If you fell into a black hole, you would stretch like spaghetti.
46.)
Matter spiraling into a black hole is torn apart and glows so brightly that it creates the brightest objects in the Universe – quasars.
47.)
The swirling gases around a black hole turn it into an electrical generator, making it spout jets of electricity billions of kilometers out into space.
48.)
The opposite of black holes are estimated to be white holes which spray out matter and light like fountains.
49.)
A day in Mercury lasts approximately as long as 59 days on earth.
50.) Twice during Mercury’s orbit, it gets so close to the Sun and speeds so much that the Sun seems to go backwards in the sky.
51.) Nicolas Copernicus was the astronomer who first suggested that the Sun was the centre, and that the Earth went round the sun.
52.) The ideas of Copernicus came not from looking at the night sky, but from studying ancient astronomy.
53.) As the earth turns, the stars come back to the same place in the night sky every 23 hours, 56 minutes and 4.09 seconds. This is a sidereal day (star day).
54.) When Neil Armstrong stepped on the Moon for the first time, he said these famous words: “That’s one small step for a man; one giant leap for mankind.”
55.) From the moon, astronauts brought back 380 kg of Moon rock.
56.) During the moon landing, a mirror was left on the Moon’s surface to reflect a laser beam which measured the Moon’s distance from the Earth with amazing accuracy.
57.) The stars in each constellation are named after a Greek alphabet.
58.) The brightest star in each constellation is called the Alpha Star, the next brightest Beta, and so on.
59.) The distance to the planets is measured by bouncing radar signals off them and timing how long the signals take to get there and back.
60.) Spacecraft have double hulls (outer coverings) which protect them against other space objects that crash into them.
61.) Manned Spacecraft have life support systems that provide oxygen to breathe, usually mixed with nitrogen (as in ordinary air). Charcoal filters out smells/
62.) Spacecraft toilets have to get rid of waste in low gravity conditions, Astronauts have to sit on a device which sucks away the waste. Solid waste is dried and dumped in space, but the water is saved.
63.) A comet’s tail is made as it nears the Sun and begins to melt. A vast plume of gas millions of kilometers across is blown out behind by the solar wind. The tail is what you see, shining as the sunlight catches it.
64.) The Shoemaker-Levy 9 comet smashed into Jupiter in July 1994, with the biggest crash ever witnessed.
65.) Giant stars have burned all their hydrogen, and so burn helium, fusing helium atoms to make carbon.
66.) The constellation of Cygnus, the Swan, contains the very biggest star in the known universe – a hyper giant which is almost a million times as big as the sun.
67.) Planet Uranus was discovered by William Herschel, who wanted to name the planet George, after King George III, but Uranus was eventually chosen.
68.) The first rockets were made 1,000 years ago in China.
69.) Robert Goddard launched the very first liquid-fuel rocket in 1926.
70.) Over 100 artificial satellites are now launched into space every year, a few of which are space telescopes.
71.) The lower a satellite’s orbit, the faster it must fly to avoid falling back to the Earth. Most satellites fly in low orbits, 300 km from the earth.
72.) Hipparchus was the first astronomer to try to work out how far away the Sun is.
73.) The red color of Mars is due to oxidized (rusted) iron in its soil.
74.) Mars’s volcano Olympus Mons is the biggest in the solar system. It covers the same area as Ireland and is three times higher than our Mount Everest.
75.) Planets have magnetic field around them because of the liquid iron in their cores. As the planets rotate, so the iron swirls, generating electric currents that create the magnetic field.
76.) Earth’s atmosphere is the only atmosphere discovered till date that human can breathe in.
77.) Earth’s atmosphere was formed from gases pouring out from volcanoes.
78.) Jupiter has no surface for a spacecraft to land on because it is made mostly from helium gas and hydrogen. The massive pull of Jupiter’s gravity squeezes the hydrogen so hard that it is liquid.
79.) Jupiter spins right round in less than 10 hours which means that the planet’s surface is moving at nearly 50,000 km/hr.
80.) The first successful planetary space probe was the USA’s Mariner 2, which flew past Venus in 1962.
81.) Voyager 2 has flown over 6 billion km and is heading out of the solar system after passing close to Neptune in 1989.
82.) To save fuel on journeys to distant planets, space probes may use a nearby planet’s gravity to catapult them on their way. This is called slingshot.
83.) Hubble’s law showed that Universe is getting bigger – and so must have started very small. This led to the idea of Big Bang.
84.) It’s believed that it was the impact of a big meteorite may have chilled the earth and wiped out all the dinosaurs.
85.) The first astronomers thought the regular pulses from far space might be signals from aliens, and pulsars were jokingly called LGMs (short for Little Green Men).
86.) Pulsars probably result from a supernova explosion - that is why most are found in the flat disc of the Milky Way, where supernovae occur.
87.) Three moons have yet been found to have their own moons: Saturn’s moon Titan, Jupiter’s Lo, and Neptune’s Triton.
88.) The largest moon in the Solar System is the Jupiter’s moon Ganymede.
89.) Saturn is not solid, but is made almost entirely of gas – mostly liquid hydrogen and helium. Only in the planet’s very small core is there any rock.
90.) Winds ten times stronger than a hurricane on Earth swirl around Saturn’s equator reaching up to 1100 km/h – and they never let up: even for a moment.
91.) The first space station was the Soviet Salyut 1 launched in April 1971; its low orbit meant it stayed up only five months.
92.) In April 2001, Dennis Tito became the first space tourist, ferried up to the ISS by the Russian Soyuz space shuttle.
93.) Einstein’s theory of general relativity shows that gravity not only pulls on matter, but also space and even ‘Time’ itself.
94.) Since the star Deneb is 1800 light years away, we see it as it was when the emperor Septimus Severus was ruling the Rome (AD 200).
95.) With powerful telescopes, astronomers can see galaxies 2 billion light years away. This means we see them as they were when the only life forms in Earth were bacteria.
96.) The slowest rotating planet is Venus, which takes 243.01 days to turn around.
97.) The fastest spinning objects in the Universe are neutron stars – these can rotate 500 times in just 1 second.
98.) In summer in Uranus, the sun does not set for 20 years. In winter, darkness lasts for 20 years. In autumn, the sun rises and sets every 9 hours.
99.) Uranus’s moon Miranda is the weirdest moon of all. It seems to have been blasted apart, and then put together again.
100.) Solar flares reach temperatures of 10 million °C and have the energy of a million atom bombs.
101.) True binary stars are two stars held together by one another’s gravity, which spend their lives whirling around together like a pair of dancers.
102.) Halley predicted that a comet he had discovered would return in 1758, 16 years after his death, and it really did. It was the first time a comet’s arrival had been predicted, and the comet was named after him as Halley’s Comet.
103.) Ceres is the biggest asteroid in the Solar System – 940 km across, and 0.0002% the size of the earth.
104.) the sun is about 5 billion years old and half a way through its life – as a medium sized star it will probably live for around 10 billion years.
105.) Neptune’s mood Triton is the coldest place in the Solar System, with surface temperatures of -236°C.
106.) Voyager 2 will beam back data until 2020 as it travels beyond the edges of the Solar System.
107.) The Pioneer 10 and 11 probes carry metal plaques with messages for aliens telling them about us.
108.) Einstein’s theory of Special Relativity (1905) shows that all measurements are relative, including time and speed. In other words, time and speed depends upon where you measure them.
109.) when things are falling, their acceleration cancels out gravity, which is why astronauts in orbits are weightless.
110.) the first space telescope was the Copernicus, sent out in 1972.
111.) Astronauts learn Scuba diving which helps them to deal with space walks.
112.) Weightlessness makes astronauts grow several centimeters during a long mission.
113.) the first living creature in space was the dog Laika on – board Sputnik 2 in 1957. Sadly, she died when the spacecraft’s oxygen supply ran out.
114.) the first manned space flight was made in April 1961 by the Soviet Cosmonaut, Yuri Gagarin in Vostok 1.
115.) the heart of a star reaches 16 million °C. A grain of sand this hot would kill someone 150 km away.
116.) Stars twinkle because we see them through the wafting of the atmosphere.
117.) the sun weighs 2,000 trillion trillion tones – about 300,000 times as much as the Earth – even though it is made almost entirely of hydrogen and helium, the lightest gases in the Universe.
118.) the sun gets hot because it is so big that the pressure in its core is so tremendous – enough to force the nuclei of hydrogen atoms to fuse to make helium atoms. This nuclear reaction is like a gigantic atom bomb and it releases huge amounts of heat.
119.) the nuclear fusion reactions in the Sun’s core send out billions of light photons every minute but they take 10 million years to reach its surface.
120.) The Hiroshima bombs released 84 trillion joules of energy. A supernova releases 125,000 trillion trillion times as such.
121.) the most distant galaxies (quasars) have red shifts so big that they must be moving away from us at speeds approaching the speed of light.
122.) when light waves from distant galaxies are stretched out his way, they look redder. This is called red shift.
123.) the moon’s gravity is 17% of the Earth’s so astronauts in space suits can jump 4 m high on the moon.
124.) the moon is the only other world that humans have set foot on. Because the moon has no atmosphere or wind, the footprints planted in its dusty surface in 1969 by the Apollo astronauts are still there today, perfectly preserved.
125.)On the moon’s surface are large dark patches called seas – because this is what people once believed they were. They are, in fact, lava flows from ancient volcanoes.
126.) Quasars are the most distant known objects in the Universe. Even the nearest is billions of light years away.
127.) the brightest quasar is 3C 273, 2 billion light years away.
128.) the brightest stars in the night sky are not actually stars, but the planets Jupiter, Venus, Mars and Mercury.
130.) Jupiter’s moon Europa may have oceans of water beneath its dry surface and it is a major target in the search for life in the Solar System.
131.) there may be 20 trillion galaxies in the Universe.
132.) Galaxies are often found in a group or clusters. One cluster may have 30 or so galaxies in it.
133.) In the 1970s the US Vikings 1 and 2 and the Soviet Mars 3 and 5 probes all reached the surface of Mars.
134.) The Solar System has nine planets including Pluto, but Pluto may be an escaped moon or an asteroid not a planet.
135.) The Milky Way belongs to a cluster of 30 galaxies called the Local Group, which is 7 million light years across.
136.) The Virgo Cluster is 50 million light years away and is made up of 1000 galaxies.
137.) for a satellite or a spacecraft to stay in orbit 200 km above the earth, it has to fly over 8 km/sec.
138.) when a spacecraft reaches 140% of the orbital velocity i.e. 11.2 km/sec, it is going fast enough to break free of the Earth’s gravity. This is called escape velocity.
139.) Saturn’s rings are sets of thin rings of ice, dust and tiny rocks, which orbit the planet around its equator.
140.) a tablespoon of neutron star would weigh about ten billion tones.
141.) the earth actually takes 365.24219 days to orbit the Sun, which is called one Solar Year. To compensate for the missing 0.242 days, the western calendar adds an extra day in February every fourth (leap) year, but misses out three leap years every four centuries.
142.) X-Rays cannot reach the earth’s atmosphere, so astronomers can only detect them using space telescopes such as ROSAT.
143.)The Sun has sunspots, the dark spots on the Sun’s photosphere (surface), 2000°C cooler than the rest of the surface.
144.) after the big bang, there was antimatter, the mirror image of matter. Antimatter and matter destroyed each other when they met, thus they annihilated. Matter just won, but the Universe was left almost empty.
145.) the afterglow of the Big Bang can still be detected as microwave background radiation coming from all over space.
146.) Dishes in the space telescopes have to be made accurate two billionths of a millimeter.
147.) you can see another galaxy with the naked eye: the Andromeda Galaxy, 2.2 million light years away.
148.) dried up riverbeds show that Mars probably once had water in its surface. There is sometimes ice at the poles and maybe water underground.
149.) for a satellite to fly off into the space, its momentum should be greater than the pull of gravity of the earth.
150.) the future of the Universe may depend on how much dark matter there is. If there is too much, its gravity will eventually stop the Universe’s expansion – and make it shrink again.
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