The Moon is the only natural satellite of Earth

The Moon is the only natural satellite of Earth:

        orbit:    384,400 km from Earth

        diameter: 3476 km

        mass:     7.35e22 kg

The Moon, of course, has been known since prehistoric times. It is the second brightest object in the sky after the Sun. As the Moon orbits around the Earth once per month, the angle between the Earth, the Moon and the Sun changes; we see this as the cycle of the Moon's phases. The time between successive new moons is 29.5 days (709 hours), slightly different from the Moon's orbital period (measured against the stars) since the Earth moves a significant distance in its orbit around the Sun in that time.

Due to its size and composition, the Moon is sometimes classified as a terrestrial "planet" along with Mercury, Venus, Earth and Mars.

The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969 (do you remember where you were?); the last was in December 1972. The Moon is also the only body from which samples have been returned to Earth. In the summer of 1994, the Moon was very extensively mapped by the little spacecraft Clementine and again in 1999 by Lunar Prospector.

The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides. The Moon's gravitational attraction is stronger on the side of the Earth nearest to the Moon and weaker on the opposite side. Since the Earth, and particularly the oceans, is not perfectly rigid it is stretched out along the line toward the Moon. From our perspective on the Earth's surface we see two small bulges, one in the direction of the Moon and one directly opposite. The effect is much stronger in the ocean water than in the solid crust so the water bulges are higher. And because the Earth rotates much faster than the Moon moves in its orbit, the bulges move around the Earth about once a day giving two high tides per day. (This is a greatly simplified model; actual tides, especially near the coasts, are much more complicated.)

But the Earth is not completely fluid, either. The Earth's rotation carries the Earth's bulges slightly ahead of the point directly beneath the Moon. This means that the force between the Earth and the Moon is not exactly along the line between their centers producing a torque on the Earth and an accelerating force on the Moon. This causes a net transfer of rotational energy from the Earth to the Moon, slowing down the Earth's rotation by about 1.5 milliseconds/century and raising the Moon into a higher orbit by about 3.8 centimetres per year. (The opposite effect happens to satellites with unusual orbits such as Phobos and Triton).

The asymmetric nature of this gravitational interaction is also responsible for the fact that the Moon rotates synchronously, i.e. it is locked in phase with its orbit so that the same side is always facing toward the Earth. Just as the Earth's rotation is now being slowed by the Moon's influence so in the distant past the Moon's rotation was slowed by the action of the Earth, but in that case the effect was much stronger. When the Moon's rotation rate was slowed to match its orbital period (such that the bulge always faced toward the Earth) there was no longer an off-center torque on the Moon and a stable situation was achieved. The same thing has happened to most of the other satellites in the solar system. Eventually, the Earth's rotation will be slowed to match the Moon's period, too, as is the case with Pluto and Charon.

Actually, the Moon appears to wobble a bit (due to its slightly non-circular orbit) so that a few degrees of the far side can be seen from time to time, but the majority of the far side (left) was completely unknown until the Soviet spacecraft Luna 3 photographed it in 1959. (Note: there is no "dark side" of the Moon; all parts of the Moon get sunlight half the time (except for a few deep craters near the poles). Some uses of the term "dark side" in the past may have referred to the far side as "dark" in the sense of "unknown" (eg "darkest Africa") but even that meaning is no longer valid today!)

The Moon has no atmosphere. But evidence from Clementine suggested that there may be water ice in some deep craters near the Moon's south pole which are permanently shaded. This has now been reinforced by data from Lunar Prospector. There is apparently ice at the north pole as well.

The Moon's crust averages 68 km thick and varies from essentially 0 under Mare Crisium to 107 km north of the crater Korolev on the lunar far side. Below the crust is a mantle and probably a small core (roughly 340 km radius and 2% of the Moon's mass). Unlike the Earth, however, the Moon's interior is no longer active. Curiously, the Moon's center of mass is offset from its geometric center by about 2 km in the direction toward the Earth. Also, the crust is thinner on the near side.

There are two primary types of terrain on the Moon: the heavily cratered and very old highlands and the relatively smooth and younger maria. The maria (which comprise about 16% of the Moon's surface) are huge impact craters that were later flooded by molten lava. Most of the surface is covered with regolith, a mixture of fine dust and rocky debris produced by meteor impacts. For some unknown reason, the maria are concentrated on the near side.

Most of the craters on the near side are named for famous figures in the history of science such as Tycho, Copernicus, and Ptolemaeus. Features on the far side have more modern references such as Apollo, Gagarin and Korolev (with a distinctly Russian bias since the first images were obtained by Luna 3). In addition to the familiar features on the near side, the Moon also has the huge craters South Pole-Aitken on the far side which is 2250 km in diameter and 12 km deep making it the the largest impact basin in the solar system and Orientale on the western limb (as seen from Earth; in the center of the image at left) which is a splendid example of a multi-ring crater.

A total of 382 kg of rock samples were returned to the Earth by the Apollo and Luna programs. These provide most of our detailed knowledge of the Moon. They are particularly valuable in that they can be dated. Even today, more than 30 years after the last Moon landing, scientists still study these precious samples.

Most rocks on the surface of the Moon seem to be between 4.6 and 3 billion years old. This is a fortuitous match with the oldest terrestrial rocks which are rarely more than 3 billion years old. Thus the Moon provides evidence about the early history of the Solar System not available on the Earth.

Prior to the study of the Apollo samples, there was no consensus about the origin of the Moon. There were three principal theories: co-accretion which asserted that the Moon and the Earth formed at the same time from the Solar Nebula; fission which asserted that the Moon split off of the Earth; and capture which held that the Moon formed elsewhere and was subsequently captured by the Earth. None of these work very well. But the new and detailed information from the Moon rocks led to the impacttheory: that the Earth collided with a very large object (as big as Mars or more) and that the Moon formed from the ejected material. There are still details to be worked out, but the impact theory is now widely accepted.

The Moon has no global magnetic field. But some of its surface rocks exhibit remanent magnetism indicating that there may have been a global magnetic field early in the Moon's history.

With no atmosphere and no magnetic field, the Moon's surface is exposed directly to the solar wind. Over its 4 billion year lifetime many ions from the solar wind have become embedded in the Moon's regolith. Thus samples of regolith returned by the Apollo missions proved valuable in studies of the solar wind.

More about the Moon

more pictures of the moon

Moon calendar showing past & future moon phases

from NSSDC

a Teacher's Guide to the Moon (concentrating on lunar geology)

a Socratic Dialog about the Moon's motion

Lunar rocks and regolith

Io and Luna, a comparison from LANL

Life Under the Moon, from Phil Plait's excellent Bitsize Astronomy site

Why the Moon looks bigger near the horizon

The Lunar size illusion, why the Moon looks bigger near the horizon

a longer explanation of the tides and their causes and effects

leap seconds and the slowing of the Earth's rotation

historical info about observations of the Moon

Lunar Meteorites

Moon Phases explained

The impact theory of lunar formation

The Origin of the Moon, with nice paintings by Dr. William K. Hartmann

The Origin of the Earth and Moon, written by G. Jeffrey Taylor, Hawaii Institute of Geophysics and Planetology

Big Bang, New Moon (from Southwest Research Institute)

New theory links moon's current orbit to its formation via a giant impact (from Southwest Research Institute)

lunar exploration

Exploring the Moon from LPI, nice images from Lunar Orbiter and others plus lots of explanatory text

Apollo info and images html

Apollo Missions

Scientific Discoveries Made During Apollo

Clementine - DSPSE (including some nice images)

Lunar Prospector

SMART-1, the first European lunar mission

The Artemis Project, a private venture to establish a permanent, self-supporting community on the Moon!

LunarSat

Yes, we really did go to the Moon, debunking the Moon Hoax theories

Fraud - Books Moon Hoax

another article on lunar ice

Lunar Nomenclature Table

(Earth and) Moon Viewer

Transient Lunar Phenomena

Inconstant Moon by John Walker, info about the Moon's changing appearance

Inconstant Moon by Kevin Clarke, for amateur astronomers

Lunar Info for the Amateur Astronomer

Names of the Full Moons

The Triple Triumph of the Moon by Isaac Asimov

The Face of the Moon, an exhibit of rare books and maps from the Linda Hall Library

The Moon in landscape photography by Joe Decker

fiction

The Moon in Science Fiction, a huge bibliography

From the Earth to the Moon, fiction by Jules Verne

Chinese Moon Legends

Eugene M. Shoemaker: Obituaries

Open Issues

Why are the maria concentrated on the near side?

Why is the Moon's center of mass off center? Because of the tidal lock with the Earth?

Now that we've found water on the Moon, what are we going do to with it?

Only twelve men have ever walked on the surface of the Moon. Who will be the 13th? Who will be the first woman?

7 reasons the world will end in 2012

Don’t know whether its true or not, but just thout of sharing it to you.

7 reasons the world will end in 2012

Scientific experts from around the world are genuinely predicting that five years from now, all life on Earth could well finish. Some are saying it’ll be humans that set it off. Others believe that a natural phenomenon will be the cause. And the religious folks are saying it’ll be God himself who presses the stop button…

1. Mayan Calendar

The first mob to predict 2012 as the end of the world were the Mayans, a bloodthirsty race that were good at two things:

Building highly accurate astrological equipment out of stone and Sacrificing Virgins.

Thousands of years ago they managed to calculate the length of the lunar moon as 329.53020 days, only 34 seconds out. The Mayan calendar predicts that the Earth will end on December 21, 2012. Given that they were pretty close to the mark with the lunar cycle, it’s likely they’ve got the end of the world right as well.

2. Sun Storms

Solar experts from around the world monitoring the sun have made a startling discovery: our sun is in a bit of strife. The energy output of the sun is, like most things in nature, cyclic, and it’s supposed to be in the middle of a period of relative stability. However, recent solar storms have been bombarding the Earth with so much radiation energy, it’s been knocking out power grids and destroying satellites. This activity is predicted to get worse, and calculations suggest it’ll reach its deadly peak sometime in 2012

3. The Atom Smasher

Scientists in Europe have been building the world’s largest particle accelerator. Basically its a 27km tunnel designed to smash atoms together to find out what makes the Universe tick. However, the mega-gadget has caused serious concern, with some scientists suggesting that it’s properly even a bad idea to turn it on in the first place. They’re predicting all manner of deadly results, including mini black holes. So when this machine is fired up for its first serious experiment in 2012, the world could be crushed into a super-dense blob the size of a basketball.

4. The Bible says…

If having scientists warning us about the end of the world isn’t bad enough,religious folks are getting in on the act aswell. Interpretations of the Christian Bible reveal that the date for Armageddon, the final battle between Good an Evil, has been set down for 2012. The I Ching, also known as the Chinese book of Changes, says the same thing, as do various sections of the Hindu teachings.

5. Super Volcano

Yellowstone National Park in the United States is famous for its thermal springs and Old Faithful geyser. The reason for this is simple – it’s sitting on top of the world’s biggest volcano, and geological experts are beginning to get nervous sweats. The Yellowstone volcano has a pattern of erupting every 650,000 years or so, and we’re many years overdue for an explosion that will fill the atmosphere with ash, blocking the sun and plunging the Earth into a frozen winter that could last up to 15,000 years. The pressure under the Yellowstone is building steadily, and geologists have set 2012 as a likely date for the big bang.

6. The Physicists

This one’s case of bog-simple maths mathematics. Physicists at Berekely Uni have been crunching the numbers. and they’ve determined that the Earth is well overdue for a major catastrophic event. Even worse, they’re claiming their calculations prove, that we’re all going to die, very soon – while also saying their prediction comes with a certainty of 99 percent- and 2012 just happens to be the best guess as to when it occurs.

7. Slip-Slop-Slap- BANG!

We all know the Earth is surrounded by a magnetic field that sheilds us from most of the sun’s radiation. What you might not know is that the magnetic poles we call north and south have a nasty habit of swapping places every 750,000 years or so – and right now we’re about 30,000 years overdue. Scientists have noted that the poles are drifting apart roughly 20-30kms each year, much faster than ever before, which points to a pole-shift being right around the corner. While the pole shift is underway, the magnetic field is disrupted and will eventually disappear, sometimes for up to 100 years. The result is enough UV outdoors to crisp your skin in seconds, killing everything it touches.

When Is the Next Doomsday (Not) Going to Happen?

Take a deep breath; Dec 21, 2012 is behind us. The Mayan calendar end-of-world debacle is over: zip, zilch, gone!

The silliness, anxiety, and paranoia leading up to the predicted end of times was so bad that on Dec. 21st — the appointed doomsday — a worried citizen left a message on my office phone that accused me of skipping town to escape Armageddon.

SLIDE SHOW: Top 5 Plans to Ensure the Continuity of our Species

If history is any example, the next cosmic doomsday prediction is always right around the corner. The Mayan blowout was just the latest in many centuries of bad calls by prognosticators who have the audacity to think they can divine the End of Everything.

So, to be a little preemptive, let’s look at just three cosmic events that might start another pop culture panic. Thankfully these aren’t born out of mythology, psychics, and misinterpreted archeoastronomy. They are real events that will inevitably be embellished by the imaginations of modern day soothsayers.

The Comet of the Century

Last September, the International Scientific Optical Network (ISON) near Kislovodsk, Russia, discovered comet C/2012 S1 (ISON). Though its closest approach to Earth is a year away, the celestial visitor is already billed as the “comet of the century.” That’s because it may be a first-time visitor to the solar system that will warm and then erupt with a lot of outgassing from pristine ices.

DNEWS VIDEO: DOOMSDAY ASTEROID

ANALYSIS: New Comet Discovered — Will It Be Spectacular?

On Nov. 28, 2013 the comet will skim above the sun’s surface at a distance slightly greater than the separation of the Earth and moon. Not doubt there will be pseudoscience predictions of the comet wreaking havoc by raising tides on the sun. The exact opposite will be the case. The sun’s tidal pull could tear apart the comet into small pieces, as has been the case for previous sungrazer-class comets.

Comet ISON is due to pass within 37 million miles of Earth in January 2014. I’m expecting to see all types of outrageous claims that the object’s feeble gravity will yank on Earth to trigger volcanoes and earthquakes.

Comet ISON has been compared with the Great Comet of 1680 (in above illustration) which, according to contemporary accounts, caused New Yorkers to be “overcome with terror at a sight in the heavens such as has seldom greeted human eyes.” A day of fasting and humiliation was set-aside in order that “the wrath of God might be assuaged.”

Likewise, soothsayers will quickly note that the comet will be at it brightest one month before Christmas 2013. “This comet, if it lives up to its billing, certainly could point to the glorious soon coming of the Lord Jesus Christ from heaven!” predicts one religious website.

The fact that the comet is anticipated to get as bright as the moon will only fuel religious and mystical speculation about its timing and significance as an omen. Chill out folks, it’s just another 4 billion year-old primeval chunk of ice from the solar system’s deep freeze, the Oort cloud.

Asteroid Apophis

NASA keeps cataloging more Earth-threatening asteroids every year. But the asteroid Apophis, named after the Egyptian spirit of evil and destruction, is legendary because it will be a record-breaker.

On April, Friday the 13th of 2029 Apophis will skim below the orbits of communication satellites and briefly be a naked-eye object scooting over the mid-Atlantic ocean.

SLIDE SHOW: Top 10 Ways to Stop an Asteroid

Earth’s gravity will deflect the comet’s trajectory. The worst-case scenario is that the chances of it striking Earth on its return on April 13, 2036 will increase to 1 in 5,500.

Apophis is the length of over three football fields. It packs enough kinetic energy to wipe out 10 million people with the power of 100,000 Hiroshima sized atomic bombs. Even in this worst case scenario a direct hit would not obliterate all life on the planet. But it certainly would not be a good day for the human race.

People will get very squeamish over the possibility of Apophisgeddon despite the best low-probability collision estimate from astronomers. Parallels no doubt will be drawn to Biblical prophecy. This is especially true because the potentially destructive path of the asteroid crosses Middle East. South America and the west coast of Africa are also along the ground track.

Congress might even debate if steps should be taken to deflect the asteroid. But given that so many legislators are tone-deaf to global warming, I wouldn’t expect any preemptive actions to be funded.

Planetary Grand Alignment

Like clockwork so-called planetary grand alignments have taken place in 1962, 1982, and 2000. This does not mean that the planets line up like pearls on a string. But they sort of gang up on one side of the sun within an angle of roughly 10 to 30 degrees — so the definition is a but mushy.

The uneventful year 1128 A.D. saw one of the tightest planetary alignments.

The doomsday best seller The Jupiter Effect in 1982 spelled out an improbable chain of events that would be triggered by the planets’ tug-of-war with the sun: tides raised on the sun’s surface would increase sunspot activity, build up the solar wind, that would effect Earth’s weather, and subsequently, Earth’s spin rate, which would then trigger earthquakes.

ANALYSIS: No Doomsday! The Quick Reference Guide

No geological disasters happened in 1982 short of a 6.0 magnitude earthquake that killed 1,500 people in Dhamar, northern Yemen. In fact the celestial alignment allowed for NASA to pull off the Voyager 2 “grand tour” of the four outer gas giant planets from 1979 to 1989.

Jupiter contains more mass than all the other planets combined, and yet it is still less than 1 percent of the sun’s mass. Therefore Jupiter’s influence on the sun is inconsequential.

Alien astronomers could measure Jupiter’s gravitational tug as an insignificant 270 mile-per-hour cyclic change in the sun’s radial velocity over the planet’s 12-year orbital period. Only if Jupiter was moved so close to the sun that its orbital period was measured in days, would some serious tidal effects be seen. This is observed with so-called “hot Jupiters,” the exoplanet WASP-18 being the most extreme case.

Running an ephemeris forward in time, with the ease of throttling H.G. Wells’ time machine, the next closest thing to a grand alignment comes in 2163 (shown above). Unless we have bombed ourselves back to pre-Columbian society by then, people in 2163 will be too science savvy to give this any thought. They will be bemused by historical accounts of the feared Jupiter Effect by their science-illiterate ancestors.

What’s ironic is that any casual surfing of the Internet shows that a lot of people are preoccupied with doom and gloom based on mythology, psychics, and patently flaky ideas. The real Earth-threats, such as global warming, seem to be too easily shrugged off as lacking solid scientific evidence. Go figure.

List of dates predicted for apocalyptic events

This is a list of predicted dates for apocalyptic events such as the Rapture, Last Judgment, or any other event that would result in the end of humanity, civilization, the planet, or the entire universe. The list shows the dates of predictions from notable groups or individuals of when the world was, or is, forecast to end.

Date (CE)	Claimant	Description	Reference(s)
2014 Apr - 2015 Mar	John Hagge and Mark Biltz	Mark Biltz in 2008 with John Hagee claim that four "blood moons" in 2014 and 2015 may represent prophecies allegedly given in the Bible relating to the second coming of Jesus Christ.	[95]
2020	Jeane Dixon	This alleged psychic claimed that Armageddon would take place in 2020 and Jesus would return to defeat the unholy Trinity of theAntichrist, Satan and the False prophet between 2020 and 2037. Dixon previously predicted the world would end on February 4, 1962.	[96]
2021	F. Kenton Beshore	Beshore bases his prediction on the prior suggestion that Jesus could return in 1988, i.e., within one Biblical generation (40 years) of the founding of Israel in 1948. Beshore argues that the prediction was correct, but that the definition of a Biblical generation was incorrect and was actually 70–80 years, placing the Second Coming of Jesus between 2018 and 2028 and the Rapture by 2021 at the latest.	[97]
2026	Messiah Foundation International	Members propagate that the world is to end in 2026, when a comet would collide with Earth in accordance with Riaz Ahmed Gohar Shahi's predictions in The Religion of God.	[98][99]
2120	Adnan Oktar	According to abjad interpretation of a hadith, this Sunni Muslim creationist claims that the Last Day will come about the year 2120.	[100]

Why Nothing Happened on December 21 2012 ?

Mayan End Age 12-21-2012 heralds a New Age of spiritual enlightenment.

Mayan Calender"Both the Hopis and Mayans recognize that we are approaching the end of a World Age... In both cases, however, the Hopi and Mayan elders do not prophesy that everything will come to an end. Rather, this is a time of transition from one World Age into another. The message they give concerns our making a choice of how we enter the future ahead. Our moving through with either resistance or acceptance will determine whether the transition will happen with cataclysmic changes or gradual peace and tranquility. The same theme can be found reflected in the prophecies of many other Native American visionaries from Black Elk to Sun Bear."— Joseph Robert Jochmans

"An Apocalypse (Greek: 'lifting of the veil' or 'revelation') is a disclosure of something hidden from the majority of mankind in an era dominated by falsehood and misconception, i.e. the veil to be lifted."— Wikipedia
"The 2012 phenomenon was a range of eschatological beliefs that cataclysmic or transformative events would occur around 21 December 2012.[1][2][3][4][5][6] This date was regarded as the end-date of a 5,126-year-long cycle in the Mesoamerican Long Count calendar,[7] and as such, Mayan festivities to commemorate the date took place on 21 December 2012 in the countries that were part of the Mayan empire (Mexico, Guatemala, Honduras, and El Salvador), with main events at Chichén Itzá in Mexico, and Tikal in Guatemala.[8][9][10]

Various astronomical alignments and numerological formulae were proposed as pertaining to this date, all unequivocally rejected by mainstream scholarship. A New Age interpretation held that the date marked the start of a period during which Earth and its inhabitants would undergo a positive physical or spiritual transformation, and that 21 December 2012 would mark the beginning of a new era.[11]"

Wikipedia (Web. February 27, 2013)
1. Robert K. Sitler (February 2006)."The 2012 Phenomenon: New Age Appropriation of an Ancient Mayan Calendar". Novo Religio: the Journal of Alternative and Emergent Religions (Berkeley: University of California Press)
2. Sacha Defesche (2007)."'The 2012 Phenomenon': A historical and typological approach to a modern apocalyptic mythology". skepsis. Retrieved 29 April 2011.
3. G. Jeffrey MacDonald (27 March 2007)."Does Maya calendar predict 2012 apocalypse?". USA Today. Retrieved 14 October 2009.
4. Hoopes 2011a
5. Hoopes 2011c
6. Hoopes 2011d
7. "2012 Maya Calendar Mystery and Math, Surviving Yucatan". Yucalandia.com. Retrieved 25 December 2012.
8. "Miles llegan a Chichén Itzá con la esperanza de una nueva era mejor [Thousands arrive to Chichén Itzá with the hope of a new better era]"(in Spanish). La Nación (Costa Rica). Agence France-Presse. 21 December 2012. Retrieved 22 December 2012.
9. Randal C. Archibold (21 December 2012)."As Doomsday Flops, Rites in Ruins of Mayan Empire". The New York Times. Retrieved 22 December 2012.
10. Mark Stephenson (2012)."End Of The World 2012? Not Just Yet". Huffington Post. Retrieved 22 December 2012.
11. Benjamin Anastas (1 July 2007)."The Final Days"(reproduced online, at KSU). The New York Times Magazine (New York: The New York Times Company): Section 6, p. 48. Retrieved 18 May 2009.

"All was predicted by the mathematical cycles of the Mayan calendars. It will change, everything will change. Mayan Day-keepers view the Dec. 21, 2012 date as a rebirth, the start of the World of the Fifth Sun. It will be the start of a new era resulting from and signified by the solar meridian crossing the galactic equator and the Earth aligning itself with the center of the galaxy.

At sunrise on December 21, 2012 for the first time in 26,000 years the Sun rises to conjunct the intersection of the Milky Way and the plane of the ecliptic. This cosmic cross is considered to be an embodiment of the Sacred Tree, The Tree of Life, a tree remembered in all the world's spiritual traditions."

Carlos Barrios, Mayan elder
- See more at: http://www.adishakti.org/mayan_end_times_prophecy_12-21-2012.htm#sthash.5mgs92ai.dpuf

2036 asteroid collision ‘effectively ruled out’

The possibility that a 325-metre-wide asteroid will impact Earth in 2036 has been “effectively ruled out” based on new data leading up to yesterday’s flyby, NASA scientists announced.

Asteroid Apophis was discovered on 19 June 2004. Credit: UH/IA

SYDNEY: The possibility that a 325-metre-wide asteroid will impact Earth in 2036 has been “effectively ruled out” based on new data leading up to yesterday’s flyby, NASA scientists announced.

When the asteroid, named Apophis after a demon from Egyptian mythology, was discovered in 2004, scientists estimated a 2.7% chance of impact in 2029 – the highest ever seen for an asteroid.

While the 2029 impact was soon ruled out, a small chance (one in 250,000) remained for a collision with Apophis in 2036 – until yesterday.

Impact odds less than one in a million

“The impact odds as they stand now are less than one in a million, which makes us comfortable saying we can effectively rule out an Earth impact in 2036,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office, in a statement.

“Our interest in asteroid Apophis will essentially be for its scientific interest for the foreseeable future,” he said.

The scientists used updated information obtained by NASA telescopes in 2011 and 2012, as well as new data from the time leading up to Apophis’ distant Earth flyby yesterday.

Next month’s close shave

When asteroid Apophis does pass Earth again in 2029, it will be the closest flyby of an asteroid of its size, at 31,300 kilometres (19,400 miles) above Earth’s surface.

However much sooner, on February 15 this year, another smaller (45 metre-wide) asteroid, called 2012 DA14, will also pass Earth at less than 30,000 km – closer than the orbit of our geostationary satellites. 2012 DA14 will not be visible to the naked eye.

More information:
NASA Asteroid Watch

The Doomsday asteroid Apophis that could hit Earth in 2036 as it whizzed past us

Pictured: The 'Doomsday' asteroid Apophis that could hit Earth in 2036 as it whizzed past us (but don't worry it was still nine million miles away)

• 1000 foot wide asteroid will brush past the Earth at a distance of 30,000km
• Scientists claim little chance of it hitting us - but scientists warn of 'tiny but real' likelihood it may in 2036
• Name inspired by two of the asteroid's co-discoverers favorite science fiction villain
• 
  

The European Space Agency's orbiting telescope has captured striking new images of the huge 'Doomsday' asteroid Apophis that could smash into Earth in 2036 - revealing it is larger than previously thought.

Long billed as a potential cause of an Extinction Level Event (ELE) for humanity, today ESA officials announced that its Herschel Space Observatory discovered that the asteroid is 1,066 feet wide, 20 percent larger than the previous estimate of 885 feet.

Whizzing past Earth at the relatively close distance of nine million miles tonight, Apophis is being closely tracked because of a 2004 study that predicted the rock has a 2.7 percent chance of hitting Earth in April 2029, which was later revised to 2036.

Scroll down for video

ESAs Herschel Space Observatory captured asteroid Apophis in its field of view during the approach to Earth on January, 5-6, 2013. This image shows the asteroid in Herschels three PACS wavelengths: 70, 100 and 160 microns

'The 20 percent increase in diameter … translates into a 75 percent increase in our estimates of the asteroid's volume or mass,' study leader Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, said in a statement.

In addition to the latest findings two free webcasts will stream live views of the asteroid as it passes, filmed from telescopes in Italy and the Canary Islands.

The video streams from Slooh Space Telescope and Virtual Telescope Project will show Apophis as a moving light streaking across the sky - although scientists have said that sadly the large space rock is too small to be seen through home telescopes.

 

More...

• The eerie 'Phantom of the Opera' neutron star that rotates faster than a helicopter's blades
• The green, green grass of Mars: Is this how the red planet once looked?

'Alone among all these near-Earth asteroids that have passed our way in recent years, Apophis has generated the most concern worldwide because of its extremely close approach in 2029 and [chances of a] potential impact, albeit small, in 2036,' said Slooh president Patrick Paolucci.

Indeed, while scientists have ruled out any possibility of a cataclysmic collision - there remains a very real chance of the asteroid Apophis smashing into Earth in 2036.

'Apophis has been one of those celestial bodies that has captured the public's interest since it was discovered in 2004,' said Steve Chesley at NASA's Jet Propulsion Laboratory in Pasadena, California.

Jan. 8, 2013: At about 36 hours from the minimum distance (9.3 million miles from Earth), potentially hazardous asteroid Apophis was imaged again with the Virtual Telescope

'Updated computational techniques and newly available data indicate the probability of an Earth encounter on April 13, 2036, for Apophis has dropped from one-in-45,000 to about four-in-a million.'

The science of predicting asteroid orbits is based on a physical model of the solar system which includes the gravitational influence of the sun, moon, other planets and the three largest asteroids. 

The potential planet killer named after a science fiction villain

• One year after its discovery, the asteroid was given the idenitfication number of 99942 in 2005.
• This made it eligible to be be named and on July 19th 2005, the asteroid was called 'Apophis'.
• Apophis is the Greek name for the the enemy of the Ancient Egyptian sun god Ra.
• He is the Uncreator, and is characterised as an evil serpent who dwells in eternal darkness and tries to consume Ra during his nightly passage.
• Roy A. Tucker, David J. Tholen, two of the asteroids co-discoverers are also fans of the science fiction television series Stargate SG-1.
• A prominent villain in that show is called Apophis, who in the mythology of that particular series, gave rise to the myth of the Egyptian god.

NASA detects and tracks asteroids and comets passing close to Earth using both ground and space-based telescopes. 

The Near Earth-Object Observations Program, commonly called 'Spaceguard,' discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.

This year Apophis, named after an Egyptian mythological demon, will not get closer than around nine million miles.

Doomsday Asteroid? An artist's rendering of the asteroid Apophis as created by the European Space Agency

Experts say the impact if Apophis struck the Earth would generate a blast equivalent to more than 500 megatons of TNT

Scientists will use the encounter to improve their estimate of just how dangerous the space rock really is to life on Earth.

In 2029, Apophis is expected to come uncomfortably close, brushing past the Earth at a distance of just 30,000 kilometres. That will put the asteroid inside the orbit of communication satellites.

Current models predict a tiny but real likelihood of Apophis colliding with the Earth in 2036.

When the asteroid was discovered in 2004 scientists calculated a one-in-45 chance of an impact in 2029.

Improved predictions later lifted the threat.

The asteroid's latest near approach will occur at midnight UK time tomorrow.

Members of the public can view the event online via the Slooh web-based sky-watching service, which collects images from observatories around the world.

'We are excited to cover this asteroid live for the general public.'

Scientists at the American space agency Nasa have calculated that if Apophis struck the Earth it would generate a blast equivalent to more than 500 megatons of TNT.

In comparison, the most powerful hydrogen bomb ever detonated, the Soviet Tsar Bomba, released 57 megatons.

 VIDEO   The 'Doomsday' huge asteroid Apophis passes by Earth 

The huge asteroid Apophis passes by Earth