7 Lunar Myths About Apollo 11

People have invented a number of myths about the moon over the years. But Apollo 11's historic trip to the lunar surface in 1969 helped to debunk many of them, as it deepened humanity's understanding of Earth's natural satellite.

Take a look at how Apollo 11 helped to dispel several familiar and interesting myths about the moon:
       

Myth 1: The moon is made of green cheese

The idea that the moon is made of green cheese originated from fables in which the reflection of the moon in a pool of water was mistaken for a wheel of cheese. Though scientists never considered the moon a dairy product, the idea permeated popular culture. 

Apollo 11, along with the lunar exploration that prepared for it, put the idea to rest with its studies of the composition of the moon. In addition to examinations of the surface by satellites, Apollo 11 and other missions returned a total of 842 lbs. (382 kilograms) of moon rocks that were clearly inedible.

Although science had ruled out the possibility that the surface of the moon could be green cheese long before the Apollo 11 mission, the lunar landscape remained mysterious. Craters from meteorite strikes suggested that the landscape contained dust, but the thickness of the dust remained uncertain. Some scientists suggested that the finely powdered dust could swallow up spacecraft that landed on the surface. The successful landings of five robotic NASA Surveyor craft in the late 1960s revealed that such worries were unwarranted.

Myth 2: There are moon bunnies on the lunar surface

Many cultures studied the light and dark regions of the moon, and surmised that the darker areas formed what looked like a giant rabbit. From Asia to South America, the folklore abounds about how, in various ways, a rabbit's image had been imprinted on the lunar surface. Other myths discuss the presence of rabbits on the moon. 

Shortly before Apollo 11 reached the moon in 1969, the following conversation took place between mission control in Houston and Michael Collins, the astronaut who remained in the lunar orbiter while Neil Armstrong and Buzz Aldrin explored the moon's surface.

Houston: Among the large headlines concerning Apollo this morning, there's one asking that you watch for a lovely girl with a big rabbit. An ancient legend says a beautiful Chinese girl called Chango-o has been living there for 4,000 years. It seems she was banished to the moon because she stole the pill of immortality from her husband. You might also look for her companion, a large Chinese rabbit, who is easy to spot since he is always standing on his hind feet in the shade of a cinnamon tree. The name of the rabbit is not reported.

Michael Collins: OK. We'll keep a close eye out for the bunny girl.

Needless to say, the astronauts didn't find any rabbits, or lovely banished women, on the lunar surface.

Myth 3: The moon has a dark side

The moon's rotation syncs with the Earth in such a way that the same face is always pointed toward the planet. As a result, nearly 40 percent of the lunar surface remains unseen by most human eyes, leading many people to refer to the back of the moon as its "dark side". However, when the moon shines during the day, its unseen or far side points toward the sun, bathing it in light.

The first people to observe the far side of the moon with their own eyes were Apollo 8 astronauts Frank Borman, Jim Lovell and Bill Anders. After the famous moonwalk, Apollo 11 astronauts rejoined the orbiting Columbia and passed behind the moon on their journey home.

Myth 4: The moon's distance from Earth is set

Though the moon is a familiar object in the sky, its distance from Earth is constantly in flux. When Neil Armstrong and Buzz Aldrin landed on the moon, they set up the lunar ranging experiment, which remains in place today. The astronauts set up a lunar laser ranging reflector, a mirror designed to reflect pulses of lasers fired from Earth. Three more mirrors have since been left on the moon for similar purposes, set by astronauts from Apollo 14 and 15 and one French-built reflector placed by the unmanned Soviet Lunokhod 2 rover.

Here's how the laser ranging reflector works: Scientists on Earth send a laser beam through an optical telescope to hit the reflectors. By measuring how long it takes the beam to travel through space to the moon and back, they can calculate the distance to the moon with an accuracy of better than one part per 10 billion. That's equivalent to determining the distance between Los Angeles and New York to a precision of one hundredth of an inch.

As a result, scientists have determined that the moon is spiraling away from the Earth at a rate of 1.5 inches (3.8 centimeters) per year.

Myth 5: The moon is a perfect sphere

Although the full moon appears as a perfectly circular disc in the night sky, it is actually asymmetrical. Its crust is thicker on the far side, while unusual mass concentrations show up on the near side.

Optical observations made from the orbiting spacecraft during Apollo 11, as well as several other Apollo missions, provided very accurate locations for 31 craters, suggesting that the center of mass of the moon did not lie at the center of its sphere, but rather was slightly displaced. Further studies demonstrated that the moon bulges slightly on its Earthward side.

Myth 6: The moon contains life

Although the idea may seem preposterous today, when Apollo astronauts first headed toward the moon, there was a concern that life in some form may exist on the lunar surface. Materials and equipment to be deployed on the lunar surface were sterilized to prevent contamination from Earth. At the same time, the returning astronauts were put through time-consuming quarantine measures to prevent bringing home potentially hazardous lunar life forms.

A study of the samples from the moon revealed no trace of past or present life on the lunar surface. A careful study was made for carbon, since life on Earth is carbon-based, but scientists found only a few dozen parts per million of the element that was native to the moon, much of which had been injected by solar wind. None of the carbon appeared to come from life processes. Minerals from the moon also lacked significant traces of volatile elements. Astronauts found no sandstone, shale or other minerals that require water to form.

The surface of the moon is simply too hazardous for life to form. The airless surface lacks a substantial atmosphere to shield growing life from radiation from the sun, and temperatures swing from minus 255 degrees Fahrenheit (minus 160 degrees Celsius) to 250 F (120 C) over the course of a month.

Myth 7: The moon is a hollow spacecraft

In 1901, science-fiction writer H.G. Wells wrote "The First Men in the Moon," a novel that depicts the interior of the moon as the home of an alien species. Other science-fiction stories followed suit. Science even got in on the act, with two Soviet scientists proposing that the moon is actually a shell-like alien spacecraft.

However, the Apollo 11 mission investigated the thickness of the moon's crust, mantle and core. One of the experiments set up by astronauts was the Passive Seismic Experiment, built to detect moonquakes over the course of three weeks. Although the experiment revealed that the moon does occasionally shake, it also showed that the vibrations are less powerful than those found on Earth over the corresponding period.

If three or more seismometers detect an event, scientists can calculate its origin. This, in turn, led to a deeper understanding of the lunar layers, revealing that the moon is not hollow.

Other Apollo missions deployed more advanced seismometers that helped further scientists' understanding of the moon's composition.

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Gliese 832c: Life-Roasting 'Super-Venus' Discovered

One of the key incentives behind hunting down exoplanets is to find alien worlds with qualities similar to Earth. But in the case of a newly-discovered exoplanet orbiting a star only 16 light-years away, although astronomers may call it ‘habitable’ and a ‘super-Earth,’ it’s likely anything but.

Gliese 832c orbits a red dwarf star and it was discovered by the international Anglo-Australian Planet Search team led by Robert Wittenmyer of the University of New South Wales, Australia. The discovery has been accepted for publication in the Astrophysical Journal.

Red dwarfs are small, dim stars that generate far less energy than our sun. Therefore, for a red dwarf-orbiting planet to maintain water in a liquid state on its surface, it must orbit much closer to the star. In the case of Gliese 832, its ‘habitable zone’ is very compact and Gliese 832c has an orbital period of just under 36 days. The possibly-rocky world, which is around 5 times the mass of Earth, is therefore considered ‘habitable.’ In fact, Gliese 832c is considered to be the third-most habitable world known so far on the Earth Similarity Index (ESI).

But don’t go having dreams of blue skies, opal oceans and lush, alien forests — this world would likely choke any life (well, life as we know it).

“Given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable,” said co-investigator Chris Tinney, also of UNSW. “A denser atmosphere would trap heat and could make it more like a super-Venus and too hot for life.”

Like Venus, Gliese 832c is probably enduring intense warming caused by a runaway greenhouse effect. In this case, although the planet’s orbital location should allow liquid water to persist, any water would likely be ripped apart on a molecular level by intense atmospheric heating and ultraviolet light from the star, a process known as dissociation.

Of course, the astronomers have no idea what chemicals are contained within Gliese 832c’s atmosphere. The world was discovered through its gravitational pull on its parent star, so no information about its atmosphere (if it indeed has one) and any water it contains is known. The wobbling effect (which can be detected through precise radial velocity measurements) was detected by combining observations by the Anglo-Australian Telescope (AAT) at Siding Spring Observatory, Australia, the 6.5 meter Magellan Telescope and the European Southern Observatory’s 3.6 meter telescope (both located in Chile).

In 2009, the same team detected another planet around Gliese 832. Thought to be a large gas giant like Jupiter, Gliese 832b has a 9 year orbit around the star. It is for this reason that astronomers believe the system to resemble the multi-planetary structure of our solar system, only more compact. And more planets could be discovered in the future.

“With an outer giant planet and an interior potentially rocky planet, this planetary system can be thought of as a miniature version of our Solar System,” added Tinney.

So beware the headlines that suggest Gliese 832c is ‘Earth-like’ — it is more likely ‘Venus-like’ and very alien to us terrestrial lifeforms.

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25 Best Space Movies Ever

1. ALIENS (1986)

2. 2001: A SPACE ODYSSEY (1968)

3. MOON (2009)

4. ALIEN (1979)

5. APOLLO 13 (1995)

6. ELYSIUM (2013)

7. THE FIFTH ELEMENT (1997)

8. WALL-E (2008)

9. TOTAL RECALL (1990)

10. STAR TREK (2009)

11. STAR WARS: EPISODE V – THE EMPIRE STRIKES BACK (1980)

12. EUROPA REPORT (2013)

13. STARSHIP TROOPERS (1997)

14. GALAXY QUEST

15. THE RIGHT STUFF (1983)

16. AVATAR (2009)

17. FORBIDDEN PLANET (1956)

18. GRAVITY (2013)

19. DARK STAR (1974)

20. SERENITY (2005)

21. DUNE (1984)

22. SILENT RUNNING (1972)

23. EVENT HORIZON (1997)

24. DESTINATION MOON (1950)

25. STAR TREK II: THE WRATH OF KHAN (1982)

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Tokamak : The Fusion Energy Reactor

The tokamak

The tokamak is the most developed magnetic confinement system and is the basis for the design of future fusion reactors using this method. It was invented in the Soviet Union during the 1960s and soon adopted by researchers around the world. The Joint European Torus (JET – pictured), located at Culham Centre for Fusion Energy, is the largest and most powerful tokamak currently operating.

The main tokamak components and functions are as follows:

• The plasma is contained in a vacuum vessel. The vacuum is maintained by external pumps. The plasma is created by letting in a small puff of gas, which is then heated by driving a current through it.
• The hot plasma is contained by a magnetic field which keeps it away from the machine walls. The combination of two sets of magnetic coils – known as toroidal and poloidal field coils – creates a field in both vertical and horizontal directions, acting as a magnetic ‘cage' to hold and shape the plasma.
• Large power supplies are used to generate the magnetic fields and plasma currents.
• Plasma current is induced by a transformer, with the central magnetic coil acting as the primary winding and the plasma as the secondary winding. The heating provided by the plasma current (known as Ohmic heating) supplies up to a third of the 100 million degrees Celsius temperature required to make fusion occur.
• Additional plasma heating is provided by neutral beam injection. In this process, neutral hydrogen atoms are injected at high speed into the plasma, ionized and trapped by the magnetic field. As they are slowed down, they transfer their energy to the plasma and heat it.
• Radiofrequency heating is also used to heat the plasma. High-frequency oscillating currents are induced in the plasma by external coils or waveguides. The frequencies are chosen to match regions where the energy absorption is very high (resonances). In this way, large amounts of power may be transferred to the plasma.

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Interstellar Movie Review

Storyline

In the near future, Earth has been devastated by drought and famine, causing a scarcity in food and extreme changes in climate. When humanity is facing extinction, a mysterious rip in the space-time continuum is discovered, giving mankind the opportunity to widen its lifespan. A group of explorers must travel beyond our solar system in search of a planet that can sustain life. The crew of the Endurance are required to think bigger and go further than any human in history as they embark on an interstellar voyage into the unknown. Coop, the pilot of the Endurance, must decide between seeing his children again and the future of the human race. Written by Warren D'Souza.

Box Office

Budget:

 $165,000,000 (estimated)

Opening Weekend:

 $47,510,360 (USA) (7 November 2014)

Gross:

 $125,080,272 (USA) (25 November 2014)

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Dust storms seen on Mars

Before the advent of Mars-orbiting spacecraft, astronomers had a sketchy view of the Red Planet's ever-changing weather. Though Mars is one of the nearest planets to Earth, the distance between it and Earth varies greatly. The two planets circle the Sun like race cars circling a track at different speeds — and Earth "laps" Mars approximately every two years.

Martian dust storms are most likely to erupt during the Spring and early Summer in the planet's southern hemisphere — a time when Mars is closest to the Sun. Since Mars has a more elliptical orbit than Earth, its distance from the Sun varies widely. This variance causes a significant variability in the Martian climate.

Local dust storms, regional obscurations, and discrete "yellow" clouds on Mars have been reported throughout the last century; however, it is the planet-encircling dust storms that have captured our attention in the age of spacecraft exploration of Mars.

Timeline: Dust storms on Mars

1796 — Astronomer H. Flaugergues noted "yellow clouds" (now known to be clouds of dust) on Mars… as opposed to fleecy, whitish water-ice clouds.

1920 — Patchy, yellow dust clouds observed and photographed at Lowell Observatory in Arizona.

1956 — First extensive observations of a planet-encircling dust storm on Mars.

1965 — Mariner 4 conducts first fly-by of Mars; sends back dust-free photographs of a narrow swath of the planet.

1969 — Mariners 6 and 7 fly by Mars to photograph clear and cool atmospheric conditions.

1971 — The first Mars-orbiting spacecraft (Mariner 9) arrives to find the planet already shrouded in dust — the first definitive planet-wide dust storm ever seen. The dust covered everything except the poles; tall volcanic peaks poked above the dust, revealing themselves as high mountains rather than as circular basins.

1973 — Ground-based telescopes detect another planet-encircling dust storm just one Martian year after the global storm viewed by Mariner 9.

1977 — Viking spacecraft watch two planet-encircling Martian dust storms in succession from a Mars orbit and, for the first time, from the surface of Mars.

1982 — Viking Lander 1 detects what appears to be another planet-encircling dust storm just weeks before the loss of communications ends its nearly seven-year observational record on the surface of another planet.

1994 — Ground-based microwave monitoring of Mars atmospheric temperatures indicates a planet-encircling dust storm in progress, the first such planet-wide storm detected since Viking.

1997 — Mars Global Surveyor begins aerobraking at Mars and finds that planet-wide warming events can be produced by as little as a regional dust storm.

2001 — In late June the Hubble Space Telescope captures a Mars opposition photograph. (Opposition occurs when Earth lies in a straight line between the Sun and an outer planet.) The image shows seasonal dust activity in Hellas and at the North Pole. In a few weeks, these regional dust storms developed into a near-global, planet-encircling dust storm. Unprecedented details of this unusually early, blossoming storm were followed by the Mars Global Surveyor, which takes daily all-planet images and measures atmospheric temperatures.

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Comparison of comets and asteroids

Comets Asteroids Made up of ice and dust Made up of rocks and metals Form tails when they pass through the inner solar system Do not form tails Typically have orbits that are very much more elliptical and tilted than those of the planets Typically have orbits that are more elliptical and tilted than those of the planets Usually orbit the Sun in two regions: the Kuiper belt (about 30 to 100 AU from the Sun) and the Oort Cloud (extending out to about 50,000 AU from the Sun) Usually orbit the Sun in the asteroid belt, a region between Mars and Jupiter Typically remain in the outermost regions of the solar system (beyond the orbit of Neptune), but can pass through the inner solar system if their orbits are elliptical enough Typically remain in the asteroid belt, a region between Mars and Jupiter May or may not orbit the Sun in the same direction as the planets Orbit the Sun in the same direction as the planets Usually undetectable to the naked eye; may become visible while passing through the inner solar system Virtually undetectable to the naked eye Meteor showers usually occur when Earth passes through a stream of particles left behind by a comet in its orbit Produce meteors (streaks of light) upon entering Earth’s atmosphere; produce meteorites if they (either whole or in part) survive the trip through Earth’s atmosphere and hit the ground

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The Early Cosmos: Out of the darkness

Imagine a night sky without the twinkling light from stars and galaxies piercing the darkness. Astronomers believe that this was the bleak picture of the universe for at least a hundred million years after the "big bang," a tremendous explosion that produced time, space, and matter about 14 billion years ago.

Although no stars and galaxies existed just after the big bang, the young cosmos was anything but dull. It was humming with activity.

The big-bang explosion ejected intense radiation and energy. In the beginning, physical conditions were so extreme that matter as we know it today did not exist. When the universe was about one millionth of a second old, the temperatures and densities dropped enough for protons and neutrons — the building blocks of atoms — to form. Within the next few minutes, the nuclei of light elements, such as hydrogen, helium, lithium, and boron, were created. When the universe cooled to about 5,400 degrees Fahrenheit (3,000 degrees Celsius), atomic nuclei could finally capture electrons to form atoms. By 300,000 years, the universe was made up mostly of clouds of hydrogen and helium atoms.

As the universe expanded and cooled, some regions of space had slightly higher densities of hydrogen. As millions of years passed, the slight differences grew large, as dense areas drew in material because they had more gravity. Researchers have dubbed this period of coalescing the "dark ages."

Dawn of Stars

The dawn of light, called the "cosmic renaissance," began as hydrogen collapsed into small areas, eventually reaching the point at which the effect of gravity became great enough to trigger nuclear fusion reactions and form the first stars. These first-generation stars were probably born at least 100 million years after the big bang.

Today, astronomers who study distant galaxies are beginning to probe the cosmic renaissance. Roughly a thousand galaxies have been identified whose light left them when the universe was about 1 billion years old. At that time stars were forming at a rate about 10 times higher than in the present-day universe. Stars in that early period were making heavier elements, such as carbon and oxygen, which mixed with original gas from the big bang to create successive generations of stars.

At greater distances (looking farther back in time) our view becomes murkier; the number of known galaxies is smaller and their distances are more uncertain. Using the deepest images from the largest ground- and space-based telescopes, astronomers are just now beginning to see into the era when the first stars may have formed.

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Meteorites

You have probably heard of a shooting or falling star, but have you ever seen one? If you have ever spent any amount of time looking up at the night sky, then you probably have - a flash of light streaking high above through the darkness for just a moment, disappearing just as quickly as it appeared - sometimes so quick that you cannot be sure if you have really seen something or imagined it. You might think that your eyes are playing tricks on you, but shooting stars are definitely real! Your parents may have told you to quickly make a wish on a shooting star before it vanishes - what will your next wish be when you get to see one?

Here’s another question for you, a little bit harder this time: do you know what a shooting star is? Their names are a little misleading and this causes some people to think that these fast moving trails of light really are stars that have fallen out of the sky. However, this is not true. Our Sun is a star, our closest star, and the other stars are many many miles away (it would take more than your lifetime to travel to them!) and since they are much bigger than a shooting star, they are certainly not responsible, so we can count them out. If you are still not sure of the answer, then you might be surprised to learn that shooting stars are just tiny bits of dust entering the Earth’s atmosphere from space. Tiny particles, like grains of sand or pebbles on a beach, like to crash into the atmosphere at amazingly fast speeds - some faster than a car travelling at his highest speed along the motorway! But don’t worry - they are not big enough to harm you! If you pick up a stone from the beach, however, you will find that a fast moving pebble does not quite look the same as a shooting star, no matter how hard you throw it. This is because the light that you see is the heat of the air around them as they fly into the atmosphere and burn up.

Sometimes something a little bigger than a pebble will shoot through the atmosphere and we seem them as fireballs - if you are lucky enough to see one of these then you might see flames shooting from it! But don’t worry, fireballs are not dangerous - like shooting stars, they are high above us.

Occasionally, however, the piece of rock can be big enough so that it does not all burn up while entering the atmosphere and it will hit the ground. We call these meteorites (while they are flying through the atmosphere as shooting stars we call them meteors, and while they are in space we call them meteoroids - it is important to remember the difference!). A whopping 38,000 meteorites have been found on Earth so far, from all over the world, but most are found in the hot desert or in freezing cold Antarctica. You may have heard stories of someone you know that has found a meteorite or maybe you have even found one yourself! If you have never had the chance to touch or see a meteorite, then you might not know that these space rocks are quite different to the ones that you are likely to find in your backyard, but not in the way that you might think.

There are three main types of meteorites: stony, iron and stony-iron. A lot of them have been smashed off from very large chunks of rock, called asteroids, in collisions before eventually finding their way to our planet. Iron meteorites, for example, are bits of metal iron cores of large asteroids that were once hot enough to have melted, causing all of their iron to sink to the centre. Stony meteorites look most like the stones that you find on Earth and come from the outer layer of asteroids, whereas stony-iron meteorites are a mixture of the two.

Comets and asteroids are leftover debris from the when the planets were being built in the Solar System. Just like asteroids, comets make falling stars, but rather than seeing one of them every so often (that are easy to miss!), there is a shower of them - astronomers call these meteor showers and they are made when the Earth moves through the tail of a comet that has been left behind after one of these icy and dusty bodies have swooped past us. You can usually see at least a few meteors during a shower, but on a particularly good show, you can sometimes see hundreds of shooting stars per hour - you can be sure not to miss one then! The best meteor showers are the Quadrantids that are at their best on the 3rd January every year, the Lyrids that are at their best on 22nd April, the famous Perseids on 12th August, the Orionids on 22nd October, the Leonids on 17th November and the Geminids on 14th December. The Geminids, it is thought, are actually dust from an asteroid called Phaethon rather than a comet - and it has been shown that Phaethon was originally part of the second biggest asteroid Pallas, but was smashed off in a mighty collision with another asteroid billions of years ago. Meteor showers are named after the constellation that they appear to be falling from. For example, the Geminids will be shooting away from the constellation, Gemini (The Twins), whereas the Perseids are from Perseus (The Hero).

Watching a meteor shower can be one of the most enjoyable things about observing the night sky, waiting with tense excitement to see the next shooting star. The best meteor shower is the Perseids - not just because it has the most meteors (although it does have as many as 100 per hour) - but because you can sit out in the garden during the warm summer night to watch them, rather than having to wrap up in your scarf, bobble hat and wooly mittens during the middle of winter, as you would have to for watching the Geminids in December!  

Near the Grand Canyon in Arizona is Meteor Crater (above).  It was formed about 50,000 years ago when a meteor about 30 meters wide and weighing 100,000 tons struck the Arizona desert at an estimated speed of 20 kilometers per second (12 miles per second).

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Comets

What  are comets?
A comet is a small world which scientists sometimes call a planetesimal. They are made out of dust and ice, kind of like a dirty snow ball.

Where do they come from?
Comets come from two places:  The Kuiper Belt and the Oort Cloud. 

Why do Comets leave their home in the Oort Cloud or Kuiper Belt?
A comet will spend billions of years in the Kuiper Belt or Oort Cloud.  Sometimes two comets will come very close to each other, or even crash into one another.  When this happens the comets change directions.  Sometimes their new path will bring them into the Inner Solar System. 

This is when a comet begins to shine. Up until now the comet has been among millions of others exactly the same, but as they approach the warmer Inner Solar System they begin to melt leaving behind magnificent tails.

Unfortunately, comets don't live very long once they enter the warmer part of the Solar System. Just like a snowman melts in the summer, comets melt in the Inner Solar System.   Although it is the most glorious part of their lives, traveling through the Inner Solar System eventually kills them.  After several thousand years they melt down to a little bit of ice and dust, not nearly enough to leave a tail. Some even melt away completely.

Would it be safe to fly through the tail of a comet?
Unlike a recent blockbuster movie showing a space ship flying past giant rocks the size of houses, a comet's tail is actually quite safe. The only thing that would hit your ship would be microscopic pieces of dust.

Did You Know?
Many people think that a comet's tail is always following behind it, but actually the coma, or tail, can either be behind the comet or in front of it. Which way the tail is pointing depends on where the Sun is. That's right, the Sun's heat and radiation produce a wind called the solar wind, as a comet gets close to the Sun it begins to melt. The gas and dust that melt off are blown away from the Sun by the solar winds. So if a comet is traveling towards the Sun then the tail will follow behind, but if the comet is traveling away from the Sun the tail will be in front of the comet.

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Asteroids

What are asteroids?
An asteroid is a large rock in outer space. Some, like Ceres, can be very large, while others are as small as a grain of sand. Due to their smaller size, asteroids do not have enough gravity to pull themselves into the shape of a ball.  Astronomers group asteroids into different categories based on the way they reflect sunlight.

The asteroid belt is divided into an inner belt and an outer belt. The inner belt, which is made up of asteroids that are within 250 million miles (402 million km) of the Sun, contains asteroids that are made of metals.

The outer belt, which includes asteroids 250 million miles (402 million km) beyond the Sun, consists of rocky asteroids. These asteroids appear darker than the asteroids of the inner belt, and are rich in carbon.

Where did the Asteroid Belt come from?

Asteroids are left over materials from the formation of the Solar System.  These materials were never incorporated into a planet because of their proximity to Jupiter's strong gravity.

How many asteroids are there?

26 very large asteroids have been discovered, which is probably most of the big ones. But there are still millions of smaller ones that we have yet to see because they are too tiny, only a mile or so across.

If we stuck all the asteroids together, how big would the new planet be?
If all the materials of all the asteroids were squashed up into one planet it would be smaller than our moon.

Did You Know ?

1. While most asteroids can be found in the Asteroid Belt, others are in strange orbits straying far from home. It is currently believed that at least 5000 asteroids cross the Earth's orbit, some coming very close. Don't worry though, asteroids and comets only hit the Earth every 100 million years or so.

2. Quaoar is the largest known non-planet object in the Solar System.  It is one tenth the size of the Earth, and is larger than all other asteroids put together. 

3. For many years Ceres was thought to be the biggest asteroid in the Solar System. It is about 600 miles wide and contains about 25% of the mass of all the asteroids combined.  However, in the summer of 2001 scientists discovered an even bigger asteroid orbiting the Sun near Pluto. 

4. On August 23, 2001, astronomers announced the discovery of a new asteroid.  The new asteroid is even bigger than Ceres, which for over two hundred years had been thought to be the largest asteroid in the Solar System. 

It was discovered looking at old photographs taken of the sky.  

5. Ida is a neat little asteroid about 36 miles wide. It is unique because it has its own little moon called Dactyl.

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Amazing Astronomy Facts

• When you look at the Andromeda galaxy (which is 2.3 million light years away), the light you are seeing took 2.3 million years to reach you. Thus you are seeing the galaxy as it was 2.3 million years ago.
• Light from the sun takes 8 minutes to reach you, thus you see the sun as it was 8 minutes ago. It might have blown up 4 minutes ago and you wouldn't know about it!
• The Earth is not a sphere! It actually is an oblate spheroid, it is squashed slightly at the poles and bulges out at the equator due to its rotation.
• Spare a thought for the constellations that never made it into the official list... these include Machina Electrica (the electricity generator), Officina Typographica(The Printing Office), and Turdus Solitarius (the solitary thrush)
• When Galileo viewed Saturn for the first time through a telescope, he described the planet as having "ears". It was not until 1655 that Christian Huygens suggested the crazy theory that they might be an enormous set of rings around the planet.
• If you could put Saturn in an enormous bathtub, it would float. The planet is less dense than water.
• A teaspoon-full of Neutron star would weigh about 112 million tonnes.
• Jupiter is heavier than all the other planets put together.
• Even on the clearest night, the human eye can only see about 3,000 stars. There are an estimated 100,000,000,000 in our galaxy alone!
• The tallest mountain in the solar system is Olympus Mons, on Mars at a height of about 15 miles, three times the height of Mount Everest. It covers an area about half the size of Spain.
• If the sun were the size of a dot on an ordinary-sized letter 'i', then the nearest star would be 10 miles away.
• Half-a-billionth of the energy released by the sun reaches the Earth
• Temperatures on Venus are hot enough to melt lead.
• If you could travel at the speed of light (186,000 miles per second) it would take 100,000 years to cross our galaxy!
• Only one side of the moon ever faces Earth. The moons period of rotation is exactly the same as it's period of orbit.
• Betelgeuse, the bright star on Orion's top-left shoulder, is so big that if it was placed where the sun is, it would swallow up Earth, Mars and Jupiter!
• If you stand on the equator, you are spinning at about 1,000 mph in as the Earth turns, as well as charging along at 67,000 mph round the sun.
• On the equator you are about 3% lighter than at the poles, due to the centrifugal force of the Earth spinning.
• The atmosphere on Earth is proportionately thinner than the skin on an apple.
• On Mercury a day (the time it takes for it to spin round once) is 59 Earth-days. Its year (the time it takes to orbit the sun) is 88 days- that means there are fewer than 2 days in a year!
• If a piece of the sun the size of a pinhead were to be placed on Earth, you could not safely stand within 90 miles of it!
• Its estimated that the number of stars in the universe is greater than the number of grains of sand on all the beaches in the world! On a clear night, we can see the equivalent of a handful of sand.
• Every year the sun evaporates 100,000 cubic miles of water from Earth (that weighs 400 trillion tonnes!)
• Jupiter acts as a huge vacuum cleaner, attracting and absorbing comets and meteors. Some estimates say that without Jupiters gravitational influence the number of massive projectiles hitting Earth would be 10,000 times greater.
• Astronomers believe that space is not a complete vacuum- there are three atoms per cubic metre.
• Saturn is not the only planet with rings- Neptune has it's own ring system.

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Astronomy Dictionary

Word Definition Absolute magnitude How bright a star would look if it were 32.6 light years away from the Earth. Absolute zero The lowest possible temperature, -273.16 degrees C. Acceleration Change in velocity (speed, or direction). Airglow The natural glow of the night sky due to reactions that take place in the Earth's upper atmosphere. Albedo The albedo of an object is how much light it reflects. A perfect reflector such as a mirror would have an albedo of 100, the moon has an albedo of 7, and the Earth has an albedo of 36. Angstrom unit Unit used to measure the wavelength of light, and other electromagnetic radiation. Annular Shaped like or forming a ring. Apastron When two stars that orbit each other are as far away from each other as they can get. Aphelion The point in an object's orbit around the Sun when it is furthest from the Sun. Apogee The point in an object's orbit around the earth when it is furthest from the Earth. Aerolite A meteorite which is stoney. Asteroid A rock, or Minor Planet orbiting the Sun. Astrology A belief that links the positions of the stars and planets to human destinies. It has no scientific background. Astronomical Unit The distance from the Earth to the Sun. Usually written AU. Astrophysics The use of physics and chemistry in the study of Astronomy. Atmosphere The gaseous area surrounding a planet or other body. Atom The smallest particle of any element. Aurora Beautiful lights seen over the polar regions which are caused when energized particles from the Sun react with the Earth's magnetic field.  Axis An imaginary straight line on which an object rotates. Background radiation Weak microwave radiation coming from space in all directions. It is believed to be the remnant of the Big Bang. Barycentre The center of gravity of the Earth and moon. Binary star A star which is actually made up of two stars orbiting each other. Black Hole A region of space around a very small and extremely massive object within which the gravitational field is so strong that not even light can escape. Bolide A brilliant meteor, which may explode during its descent through the Earth's atmosphere. Bolometer A sensitive radiation detector. Celestial sphere An imaginary sphere surrounding the Earth. It is used to help astronomers explain where objects are found in the sky.  Cepheid A variable star that scientists can use to determine how distant a galaxy or star cluster is. Charge-Coupled Device (CCD) A sensitive imaging device which is replacing photography in most branches of Astronomy. Chromosphere Part of the Sun's atmosphere, it is visible during a total solar eclipse. Circumpolar star A star which never sets, but can be viewed year round. Clusters A group or stars or galaxies which are held together by their common gravity. Color index A measure of a star's color, which tells scientists how hot the star's surface is. Coma The hazy-looking patch surrounding the nucleus of a comet. Comet A small, frozen mass of dust and gas revolving around the sun. Conjunction When a planet appears to come close to another planet or star. It only appears to come close because it moves in between the other object and the Earth. Constellation A grouping of stars which have been given names by ancient astronomers because of the way they look. Corona The outermost part of the Sun's atmosphere. Coronagraph A type of telescope designed to view the Sun's Corona. Cosmic rays High-speed particles that reach the Earth from Outer Space. Cosmology The study of the universe. Day Amount of time it takes the Earth to spin once on its axis. Density The compactness of matter. Direct motion Objects moving around the Sun in the same direction as the Earth are moving in direct motion, objects moving in the opposite direction are moving in retrograde motion. Diurnal motion The apparent motion of the sky from East to West caused by the Earth moving from West to East. Earthshine The faint glow of the moon when the side facing Earth is dark. Caused by light reflecting off the Earth. Eclipse When our view of one object in the sky is blocked by either another object or the Earth's shadow. Ecliptic The path the Sun, Moon, and planets all follow in the sky. Ecosphere The area around a star where it is just the right temperature for life to exist. Electron Negative particle which orbits an atom. Element Substance which cannot be broken down any further. There are 92 known elements. Equinox March 21st and September 22nd. Twice a year when the day and night are the same amount of time all around the world. Escape velocity The speed an object must have in order to escape from another object's gravity. Exosphere The outermost part of the Earth's atmosphere. Flares (Solar Flares) Beautiful eruptions in the outer part of the Sun's atmosphere. Galaxy A group of stars, gas and dust held together by gravity. Gamma ray Extremely short-wavelength and energetic electromagnetic radiation. Geocentric Simply means the Earth in the Center. People used to believe the Universe was geocentric, or that the Earth was in the center of the Universe. Geophysics Study of the Earth using Physics. Gibbous When the Moon is more than half full, but less than completely full. HI region Cloud of neutral hydrogen. HII region Cloud of ionized hydrogen. Hertzsprung-Russell Diagram A diagram which helps scientists understand different kinds of stars. click here to learn more. Hubble Constant The relationship between the distance of an object and the speed at which it is traveling away from us. The further away an object is the faster away from us it is traveling. Inferior planets Mercury and Venus which lie closer to the Sun than the Earth are called inferior planets. Ionosphere A region of the Earth's atmosphere. Kelvin A measurement of temperature often used in astronomy. 0 degrees Kelvin equals -273 degrees Celsius and -459.4 degrees Fahrenheit. Kepler's Laws of Planetary Motion 1. The planets move in elliptical orbits with the Sun at one focus. 2. An imaginary line joining the center of a planet to the center of the Sun sweeps the same amount of space all the time. 3. The time it takes a planet to orbit the Sun is related to how far away from the Sun an object is. Kirkwood gaps Regions in the asteroid belt where almost no asteroids can be found. This is due to the fact that the giant planet Jupiter changes the orbits of any object which enters these areas. Light Year The distance which a ray of light would travel in one year. This is about 6,000,000,000,000 (6 trillion) miles. Limb The edge of any object in Outer Space. The edge of the Moon for example. Local Group A group of around two dozen galaxies. It is the group to which our galaxy belongs. Lunation Period between new moons. 29 days 12 hours 44 minutes. Magnetosphere Region around an object where the influence of the object's magnetic field can be felt. Mass How much matter an object contains. It is not the same as weight, although an object's mass does help determine how much it will weigh. Meteor A shooting star, observed when a particle of dust enters into the Earth's atmosphere. Meteorite An object from Outer Space, such as a rock, that falls into the Earth and lands on its surface. Meteoroids Any small object in Outer Space, such as dust or a rock. Micrometeorites An extremely small object. They are so small that when they hit the Earth's atmosphere they do not create a shooting star effect. Milky Way Our Galaxy. (The word "Galaxy" actually means milky way in Greek). Minor planet Asteroid Molecule A group of atoms linked together. Multiple star A group of stars that orbit each other. Nadir That point on the celestial sphere directly below the observer. Nebula A cloud of gas and dust. Neutrino A very small particle with no mass or charge. Neutron star The remnants of a dead star. They are incredibly compact and spin very quickly, some spin 100 times a second. Nova A star which suddenly flares up to many times its original brightness before fading again. Oblate Spheroid A planet that is not perfectly round because it is wider in the middle and shorter from top to bottom. Occultation The covering up of one celestial body by another. Opposition When a planet is exactly opposite the Sun so that the Earth is between them. Orbit The path one object takes around another. Ozone An area in the Earth's upper atmosphere which absorbs many of the lethal radiations coming from space. Parallax The shift of an object when it is viewed from two different places. For example if you close one eye and look at your thumb nail, and then switch eyes, you will see everything in the background move back and forth. Scientists use this to measure the distance to stars. Parsec 3.26 light years Penumbra The lighter part of a shadow found on the shadow's edge. Periastron When two stars that orbit each other are at their closest point. Perigee The point in an object's orbit around the Earth when it is closest to the Earth. Perihelion When an object which revolves around the Sun is at the closest point it gets to the Sun. Perturbations The disturbances in the orbit of a celestial object caused by the gravitational pull of another object. Phases The apparent change in the shape of the Moon, Mercury, and Venus due to how much of the sunlit side is facing the Earth. Photosphere The bright surface of the Sun. Planet An object moving around a star. Planetary nebula A nebula of gas surrounding a star. Precession The Earth behaves like a spinning top. Its poles are spinning in circles causing the poles to point in different directions over time. It takes 25,800 years for the Earth to complete one precession. Proper motion The motion of the stars across the sky as seen from Earth. Closer stars have a higher proper motion than more distant ones, just as in your car closer objects such as road signs seem to move faster than distant mountains and trees. Proton The center of an atom is made up of one or more protons. It has a positive charge. Quasar A very distant, immensely bright object. Radiant The area in the sky where during a meteor shower the meteors appear to radiate from. Radio galaxies Galaxies which are extremely powerful emitters of radio radiation. Red shift When an object is traveling away from the Earth, the light from this object is stretched out, making it look redder. Revolve When something is moving in a circle around another object, such as the way the Moon Circles the Earth, it is said to revolve around that object. Rotate When an object spins it is said to be rotating. Saros cycle A period of 18 years 11.3 days in which eclipses repeat themselves. Satellite A small object orbiting a larger one. There are many electronic objects that orbit the Earth. Scintillation Twinkling of stars. Due to the Earth's atmosphere. Seeing The condition of the Earth's atmosphere at a particular time. If the sky is clear astronomers say there is good seeing. Selenography The study of the Moon's surface. Seyfert galaxies Galaxies with small bright centers. Many Seyfert galaxies are good sources of radio waves. Shooting star A light in the atmosphere caused by a meteor falling towards the Earth. Sidereal Period The period of time that it takes an object in space to complete one full orbit in relation to the stars. Solar System The system of planets and other objects orbiting the star Sol, which happens to be our Sun. Solar wind A steady flow of particles streaming out from the Sun in all directions. Solstice 22 June, and 22 December. Time of the year when the day is either shortest, or longest depending on where you are. Spicules Jets up to 16,000 kilometers in diameter in the Sun's atmosphere. Stratosphere Level of the Earth's atmosphere from about 11-64 kilometers (7-11 miles) above sea level. Star A self-luminous object that shines through the release of energy produced by nuclear reactions at its core. Supernova A super bright explosion of a star. A supernova can produce the same amount of energy in one second as an entire galaxy. Sundial Ancient instrument used to tell time. Sun spots Dark patches on the Sun's surface. Superior planets The planets which lie further from the Sun than the Earth. Synchronous satellite An artificial satellite which moves around the Earth at the same speed that the Earth rotates, so that it is always above the same part of Earth. Synodic Period The time it takes an object in space to reappear at the same point in relation to two other objects, e.g., the Earth and Sun. Syzygy The position of the Moon in its orbit when at new or full phase. Terminator The line between day and night on any celestial object. Thermocouple An instrument used for measuring very small quantities of heat. Time dilation The idea that as you approach the speed of light time slows down and mass increases. Trojans asteroids Asteroids that circle the Sun following Jupiter's orbit. Troposphere The lowest part of the Earth's atmosphere. Umbra The dark inner part of a sunspot, or shadow. Variable stars Stars which fluctuate in brightness. Zenith Point directly above your head in the night sky.

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