• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

Asteroid Near-Misses (AKA: Holy Shit! We're All Going to Die)

Russian spacecraft to crash to Earth on Sunday
The remainder of the crippled Phobos-Grunt spacecraft is set to crash to Earth on Sunday following its botched mission to Mars, space experts have said.
By Nick Collins, Science Correspondent
7:43PM GMT 12 Jan 2012

The minibus-sized Russian craft has been in a low orbit around Earth since losing contact with engineers shortly after its launch on November 8.
It had been intended to explore Phobos, one of Mars's two moons, but became stranded while still orbiting Earth and attempts to put it back on its original course failed.
Most of its mass is expected to burn up as the craft re-enters the atmosphere but 20 or 30 pieces of small debris collectively weighing about 200kg could reach Earth.

In a normal re-entry about 20 per cent of the space junk's mass would be likely to reach Earth, but in the case of Phobos-Grunt it could be even less because it contains large quantities of unused fuel which will burn or dissipate in the atmosphere.

In theory the remains could land anywhere south of Watford or north of the Falkland Islands, with a sea landing most likely due to the size of the oceans relative to the continents.
But scientists said observers would be unlikely to even see the debris crash to Earth unless it flew directly overhead in a clear sky, and that the chances of anyone being injured were absolutely minute.

Prof Richard Crowther of the UK Space Agency said: "The chances are so low – it certainly doesn't keep me awake at night worrying about the probability of a piece of space debris coming through my roof."
He added, however, that international space agencies need to discuss the amount of disused equipment being left in Earth's orbit amid fears space junk could reach a "critical mass" where damaging collisions with active satellites and space craft become inevitable.

The craft will explode on its descent meaning any material reaching the ground could be spread over an area measuring 200km long and 20km wide, and many pieces will be so small they would be hard to spot on the ground.

British experts based at RAF Fylingdales in North Yorkshire will monitor the craft as it descends but even as it begins its last orbit, 90 minutes before it arrives, they will only be able to predict its landing spot with an uncertainty of 4,000km.

http://www.telegraph.co.uk/science/spac ... unday.html
 
OK, you can take the crash helmet off now:

Phobos-Grunt: Failed probe 'falls over Pacific'
By Jonathan Amos, Science correspondent, BBC News

Orbital tracking reports suggest Russia's failed Mars probe, Phobos-Grunt, fell back to Earth on Sunday, to be destroyed over the Pacific.
Russian, US and European sources announced the demise of the craft within minutes of each other.

It brings to an end the sorry story of this mission, which promised to return rocky samples from Mars' biggest moon.
Instead, after its launch in November, Phobos-Grunt could not get more than 345km from Earth before stalling.

Once it became clear that controllers could not establish contact with the probe and diagnose its faults, a fiery dive back to Earth was inevitable.

The spacecraft's last orbit took it over Japan, and the Solomon Islands, and to the east of Australia and New Zealand. Conflicting reports then had the final re-entry point across a great swathe of the Southern Ocean. Certainly, it seems Phobos-Grunt was down and destroyed before it could have passed over South America.

etc...

http://www.bbc.co.uk/news/science-environment-16491457
 
NEOShield to assess Earth defence
http://www.bbc.co.uk/news/science-environment-16651642

Mapping Earth's surface in 3D
Video tracks stricken Mars probe
US spaceplane 'spying on China'
Sharp-eyed Pleiades returns first images

NEOShield is a new international project that will assess the threat posed by Near Earth Objects (NEO) and look at the best possible solutions for dealing with a big asteroid or comet on a collision path with our planet.

The effort is being led from the German space agency's (DLR) Institute of Planetary Research in Berlin, and had its kick-off meeting this week.

It will draw on expertise from across Europe, Russia and the US.

It's a major EU-funded initiative that will pull together all the latest science, initiate a fair few laboratory experiments and new modelling work, and then try to come to some definitive positions.

Industrial partners, which include the German, British and French divisions of the big Astrium space company, will consider the engineering architecture required to deflect one of these bodies out of our path.

Should we kick it, try to tug it, or even blast it off its trajectory?

"We're going to collate all the scientific information with a view to mitigation," explains project leader Prof Alan Harris at DLR.

"What do you need to know about an asteroid in order to be able to change its course - to deflect it from a catastrophic course with the Earth?"

It's likely that NEOShield will, at the end of its three-and-a-half-year study period, propose to the politicians that they launch a mission to demonstrate the necessary technology.

The NEO threat may seem rather distant, but the geological and observational records tell us it is real.


The European Space Agency designed - but never launched - the Don Quijote mission
On average, an object about the size of car will enter the Earth's atmosphere once a year, producing a spectacular fireball in the sky.

About every 2,000 years or so, an object the size of a football field will impact the Earth, causing significant local damage.

And then, every few million years, a rock turns up that has a girth measured in kilometres. An impact from one of these will produce global effects.

The latest estimates indicate that we've probably found a little over 90% of the true monsters out there and none look like they'll hit us.

It is that second category that merits further investigation.

Data from Nasa's Wise telescope suggests there are likely to be about 19,500 NEOs in the 100-1,000m size range, and the vast majority of these have yet to be identified and tracked.

New telescopes are coming that will significantly improve detection success. In the meantime, the prudent course would be to develop a strategy for the inevitable.

The strongest mitigation candidates currently would appear to be:

Kinetic impactor: This mission might look like Nasa's Deep Impact mission of 2005, or the Don Quijote mission that Europe designed but never launched. It involves perhaps a shepherding spacecraft releasing an impactor to strike the big rock or comet. This gentle nudge, depending when and how it's done, could change the velocity of the rock ever so slightly to make it arrive "at the crossroads" sufficiently early or late to miss Earth.

"The amount of debris, or ejecta, produced in the impact would affect the momentum of the NEO," says Prof Harris.

"Of course, that will depend on what sort of asteroid it is - its physical characteristics. What's its surface like; how porous or dense it is? This is really something you would want to test with a demonstration mission."


Can a gravity tractor be relied upon to work for as long as its effort is needed?
"Gravity tractor": This involves positioning a spacecraft close to a target object and using long-lived ion thrusters to maintain the separation between the two. Because of gravitational attraction between the spacecraft and the NEO, it is possible to pull the asteroid or comet off its trajectory. "It's like using gravity as a tow-rope," says Prof Harris. "It's not straightforward of course. Can you be sure those thrusters will keep working for the time they're needed - a decade or more? Do you have confidence that the spacecraft can look after itself autonomously all that time? These are the sorts of technical problems we will look at."

In both scenarios, the effects are small, but if initiated years - even decades - in advance should prove effective enough.

What we've learnt about asteroids, however, is that they are not all the same. Different rocks are likely to need different approaches.

One method often discussed but about which there is great uncertainty is "blast deflection" - the idea that you would detonate a nuclear device close to, or on the surface of (even buried under the surface), an incoming rock.

The Russian members of the NEOShield consortium will take a close look at the option.

At present, I detect a lot of scepticism out there about this approach. Delivering the device to just the right place would prove very difficult, and the outcomes, depending on the composition and construction of the NEO, would be very hard to predict. But some better numbers than we have currently are required and TsNIIMash, the engineering arm of the Russian space agency (Roscosmos), will gather all the available data.

"What we want to do is take a comprehensive view, to try to draw everything we know together, with the right expertise so that this thing has momentum," commented Dr Ralph Cordey, from Astrium UK.

"We will look at the spectrum of techniques, trying to see which ones might be applicable in different cases. And then taking it to a level where we do some detailed design work on a possible mission to demonstrate one or more of these techniques."

And Prof Harris added: "At the end of this, we want to be able to say to the space agencies 'if you're interested in asteroid mitigation, this is what we think. We have six countries represented in our consortium and we're all agreed this is the way to go'.

"The politicians would then have everything on a plate. All they have to do is decide whether or not to execute the mission."
Click to expand...
 
Asteroid makes near-miss fly-by

An asteroid hurtled past the Earth on Friday in something of a cosmic near-miss, making its closest approach at about 1600 GMT.
The asteroid, estimated to be about 11m (36ft) in diameter, was first detected on Wednesday.
At its closest, the space rock - named 2012 BX34 - passed within about 60,000km of Earth - less than a fifth of the distance to the Moon.

Astronomers stressed that there had been no cause for concern.
"It's one of the closest approaches recorded," said Gareth Williams, associate director of the US-based Minor Planet Center.
"It makes it in to the top 20 closest approaches, but it's sufficiently far away... that there's absolutely no chance of it hitting us," he told the BBC.

The asteroid's path made it the closest space-rock to pass by the Earth since object 2011 MD in June 2011.
Earlier estimates had put the asteroid's closest distance at as little as 20,000km, but studies by observatories overnight into Friday showed it would pass at a more comfortable distance.

Although the asteroid was not visible to the naked eye, Dr Williams said that keen backyard astronomers had been busy getting a look.
"We've had three sets of observations in the last few hours from amateur observers in the UK," he said.

http://www.bbc.co.uk/news/science-environment-16756450

We live to worry another day...
 
Asteroid heads towards Earth with one in 625 chance of hitting planet
An asteroid with a one in 625 chance of striking Earth in 30 years' time has been identified by NASA.
By Rosa Prince, New York
5:50PM GMT 28 Feb 2012

The 460 foot ball of rock named 2011 AG5 is potentially on course to hit this planet on February 5, 2040.
The United Nations Action Team on near-Earth object has begun discussions about how to divert the asteroid, amid fears that the likelihood of a collision could increase over the next few years.

While the object has the potential to wipe out millions of lives if it landed on a city, it is far smaller than the nine mile wide asteroid which is believed to have led to the extinction of the dinosaurs 65 million years ago.

Scientists have only been able to observe half of 2011 AG5's orbit, and are hoping to obtain more information about the asteroid's course between 2013 and 2016, when it will be possible to monitor it from the ground.
This will allow them to decide whether action needs to be taken to attempt to alter the course of the object.

NASA has said that options include deflecting the asteroid by attaching a probe to it and using the extra gravity this would create to steer it away from Earth over the course of millions of light years. [ :shock: sic]
Nuclear weapons could also be used to break up the asteroid, although this would probably create a potentially deadly shower of rocks.

According to sky scans carried out by NASA, there are around 19,000 "mid-sized" asteroids of between 330 and 3,300 feet wide within 120 million miles of Earth. All have the potential to destroy an area the size of a city were they to strike.

The Aphophis asteroid, which is the size of two and a half football pitches, is on course to pass close to the Earth in 2036, coming within 18,300 miles of this planet. Scientists expect that it will be visible from most of Europe, Africa and Asia.

http://www.telegraph.co.uk/science/spac ... lanet.html

Well, I won't worry much about 2011 AG5 - I'm very unlikely to be around in 2040. (The way I feel now, I'll be lucky to see out this week..)
 
April Fools' Day Asteroid Zips Close by Earth
http://www.space.com/15121-april-fools- ... flyby.html
by Tariq Malik, SPACE.com Managing Editor
Date: 31 March 2012 Time: 10:46 AM ET

This graphic depicts the orbit of asteroid 2012 EG5 (in blue) during its April Fool's Day flyby of Earth on April 1, 2012.
CREDIT: NASA/JPL

This story was updated at 10:18 a.m. ET.

An asteroid the size of a passenger jet zoomed near the Earth Sunday (April 1), just in time for April Fools' Day, but the space rock flyby posed no threat of hitting our planet, NASA officials said.

The asteroid 2012 EG5 was closer than the moon when it flew by Earth at 5:32 a.m. EDT (0932 GMT). The space rock is about 150 feet wide (46 meters), according to a NASA records. Scientists with the space agency announced the April Fools' asteroid flyby on Friday, March 30.

"Asteroid 2012 EG5 will safely pass Earth on April 1," scientists with NASA's Asteroid Watch program at the Jet Propulsion Laboratory in Pasadena, Calif., wrote in a Twitter statement.

The End-Time is Here www.the-end.com2008 was God's last warning, 2012 is economic collapse & WW III"Shocking" 2012 Horoscope www.PremiumAstrology.comWhat Does 2012 Have In Store For You? Shockingly Accurate. See Free!Unlimited Wi-Fi: £9.95/m Boingo.comInternet access on laptops, tablets and mobile at thousands of hotspotsAds by Google
The space rock may have visited Earth on April Fools' Day, but its flyby was no prank. The asteroid crept within 143,000 miles (230,000 kilometers) of Earth during its closest approach, which is just over half the distance between Earth and the moon's orbit. The moon typically circles the Earth at a distance of 238,000 miles (382,900 km).

Asteroid 2012 EG5 was the third relatively small asteroid to buzz the Earth in seven days. Two smaller asteroids passed near Earth on Monday (March 26).

Early Monday, the bus-size asteroid 2012 FP35 came within 96,000 miles (154,000 km) of Earth. It was followed a few hours later by asteroid 2012 FS35, which is the size of a car and passed Earth at a range of 36,000 miles (58,000 km).

Like asteroid 2012 EG5, those two smaller space rocks on Monday posed no risk of hitting Earth. Those space rocks were so small they would not survive the trip through Earth's atmosphere, even if they were aimed at our planet, Asteroid Watch researchers said.

Asteroid 2012 EG5 was discovered on March 13 by astronomers searching for near-Earth space rocks. Another space rock, the asteroid 2012 FA57, was discovered on March 28 and will fly by Earth on April 4 when it passes at a range just beyond the orbit of the moon.

Scientists with NASA's Near-Earth Object Program at JPL and other teams of astronomers regularly monitor the sky for larger, potentially dangerous asteroids to determine if they pose an impact threat to Earth.

You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.
Click to expand...
 
Newly found asteroid buzzes Earth
http://phys.org/news/2012-05-newly-asteroid-earth.html
May 29th, 2012 in Space & Earth / Space Exploration

Discovery images of asteroid KT42. Credit: Catalina Sky Survey/Mt. Lemmon Observatory

A newly found space rock will give Earth a close shave on May 29, passing by at a distance of just 14,440 kilometers (8,950 miles). That distance puts the small asteroid, named 2012 KT42, in the top ten list of closest asteroid approaches. In fact, this is the sixth closest approach to date. The close pass will occur at about 07:00 UTC (03:00 EDT, midnight PDT in the US) on May 29. 2012 KT42 is estimated to be between 3-10 meters in size, and while there is no possibility this asteroid will hit Earth, even if it did, it would surely burn up in the atmosphere.

The sequence of images above were sent to us by Alex Gibbs from the Catalina Sky Survey, who made the discovery of 2012 KT42 with the 1.5 meter telescope on Mt. Lemmon, Arizona. Gibbs also discovered a similar sized asteroid earlier this year, 2012 BX34, and shared with Universe Today the behind the scenes activities in the discovery of a near-Earth asteroid.

Below is an animation of images of 2012 KT42 taken by Ernesto Guido, Nick Howes and Giovanni Sostero from the Remanzacco Observatory.

An animation showing the motion of 2012 KT42. Each frame is a 5-second exposure through a 2.0-m telescope. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero from the Remanzacco Observatory.

The team said that at the time they took the images on May 28, 2012 KT42 was moving at about ~3.63 “/min and its magnitude was ~17.5. The images were take with the Siding Spring-Faulkes Telescope South through a 2.0-m f/10.0 Ritchey-Chretien telescope.

An interesting note pointed out by the Remanzacco team is that on May 29 at about 10:10 UT, 2012 KT42 will transit across the face of the Sun, and this could be seen from Africa, the Middle East, Asia. But it will be hard to see, if the diameter is about 5m, then the object would only appear about 0.006 of a degree against the solar disk.

In our article about Gibbs’ earlier discovery, he noted that when astronomers look through telescopes, asteroids don’t look much different from stars – they are just points of light. But asteroids are points of light are moving; however they are moving slow enough that to detect the motion, astronomers take a series of images, usually four images spaced 10-12 minutes apart.

Then, the observers run specialized software to examine their images for any star-like objects that are moving from one image to the next. The software removes any candidates that correspond to known objects or main-belt asteroids. Gibbs said the software has a low detection threshold to avoid missing anything, so the observer looks over what the software found and determines which are real. The remaining objects that the software determines could be interesting are then sent in to the Minor Planet Center (MPC) at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, for the team or others to follow up.

Thanks to Alex Gibbs and the Remanzacco team for sharing their images.
You can see more info about 2012 KT42 at JPL’s Small Body Database website, or at the Minor Planet Center.

Source: Universe Today
Click to expand...
 
Earth threatened by glowing green asteroid?
http://phys.org/news/2012-06-earth-thre ... eroid.html
June 6th, 2012 in Space & Earth / Space Exploration

Killer asteroid coming for the Earth?

The Daily Mail is reporting that a youtube user has found a strange object while poking around in Google Sky. It looks suspiciously like a glowing green asteroid and he claims it’s heading right for us. But before we call in the experts, let’s do a little bit of critical analysis on our own.

First off, the image raises alarm bells because of the apparent size of the object. Without knowing how far away it may be, it’s hard to say how large it would actually be, but we can put some limits on it. I looked up the region on Aladin and the angular distance between the two stars just to the upper right of the object is 1 arc minute. The object seems to be about that size, so we can use that as a baseline.

Assuming that the object was somewhere in the vicinity of Pluto (roughly 6 billion km), doing a bit of quick geometry means the object would be somewhere around 580,000 km. To put that in context, that’s about 40% the diameter of the Sun. If that were the case, this wouldn’t be an asteroid, it would be a small star. The funny thing about stars is that they tend to be somewhat bright and a lot more round. So that rules out that extreme.

Enlarge
2011 MD on Monday, June 27, 2011 at 09:30 UTC with RGB filter. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South.

But what if it were very close? At the distance of the moon, that would mean the object would be about 300 km in diameter which would make this thing slightly smaller than the largest asteroid, Ceres. However, this raises another issue: With that much mass, the object should still be pretty round. Additionally, with such a size and distance, it would be very bright. And it’s not.

Even closer we run into additional issues. Astronomical images aren’t taken as a single color image. Images like this are taken in 3 filters (RGB) and then combined to make a color image. If the object is nearby, it moves from image to image, showing up in the final image in 3 places, each as a different color. For example, here’s an image of 2011 MD illustrating the effect. Given the object in question doesn’t have this tri-color separation going on, it can’t be nearby.

So this has pretty much ruled out anything anywhere in our solar system. If it’s close, it should have color issues and be bright. If it’s far, it’s too massive to have been missed. Outside of our solar system and it wouldn’t have any apparent motion and should be visible in other images. And it’s not.

In fact, searching the various databases from which Google Sky draws its data (SDSS, DSS, HST, IRAS, and WMAP), the killer asteroid doesn’t appear at all. Thus, it would seem that this object is nothing more than a technical glitch introduced by Google’s stitching together of images. Sorry conspiracy theorists. No Planet X or Nibiru out there this time!

Source: Universe Today
Click to expand...
 
Non-Profit Steps Up to Fill Killer-Asteroid Monitoring Gap
http://www.wired.com/wiredscience/2012/ ... l-mission/
By Adam MannEmail Author June 28, 2012 | 8:00 am | Categories: Space

To combat a space-based threat, try a space-based solution. Within the next six years, the B612 Foundation plans to launch the Sentinel Mission – a dedicated infrared telescope that will be on the lookout for killer asteroids.

The project will be the first privately funded deep space mission and will greatly expand the catalog of known near-Earth objects. The foundation estimates it will cost several hundred million dollars to build the telescope and hopes it will be ready to go by 2017.

While large comets and asteroids strike the Earth infrequently – the last major one killed the dinosaurs 65 million years ago — they are a potential hazard. An object larger than half a mile across could cause global climate shifts and mass extinctions. Smaller rocks around 200 feet in diameter could easily level a city.

Several ground-based telescopes and projects, such NASA’s Near-Earth Object program, have eyes on the sky to search for potentially hazardous space rocks under the aegis of the Spaceguard Survey. Collectively, they have detected nearly 10,000 objects and an estimated 90 percent of near-Earth asteroids larger than a half mile.

Near Earth, there still lurk about half a million asteroid larger than the one that cause the 1908 Tunkusga event, when a large object from space exploded over Siberia, destroying a zone roughly equal to the San Francisco Bay Area.

“That’s the urgency of this,” said Ed Lu, a chairman of the B612 Foundation and former space shuttle astronaut. “If there is an asteroid out there that may strike in the next 10 or 20 years, then time’s a wastin’.”


The company currently plans to launch their telescope on a SpaceX Falcon 9 rocket, sending the spacecraft toward the inner solar system into a gravity assist slingshot around Venus. The roughly 25-foot telescope will orbit the sun from between 0.6 and 0.8 times the Earth-sun distance and is planned to have a 5.5-year initial mission to find 90 percent of asteroids larger than 500 feet. It also intends to map out a significant number of 100-foot-diameter asteroids.

After launch, the telescope will immediately begin to search for near-Earth objects and calculate their orbits, making sure that none of them intersect with Earth’s. Being a dedicated asteroid-finding mission and working from space will give it a tremendous advantage over ground-based telescopes. Within a month, Lu calculates that the telescope will find 16,000 objects, more than doubling the known catalog. Ultimately, he hopes to expand the number of known asteroids by a hundred-fold.

The project will release asteroid trajectories publicly through an existing network that includes the Minor Planet Center in Cambridge, Massachusetts. Many researchers are eager to get their hands on such data. At a conference the B612 Foundation held last year, roughly 50 interested scientists gathered to discuss near-Earth asteroid threats.

Though such a project has been suggested in the past, NASA has never seriously considered a dedicated asteroid-hunting space telescope, and this is not likely to change in the current tight budget climate. Lu said that developments in processing speed and hardware over the last 10 years, as well as the emergence of private spaceflight companies, have made it possible for a private non-profit to step in and take the project on.

He compared the estimated hundreds of millions of dollars they need to the amount necessary to build a metropolitan museum or performing arts center. While the project is ambitious, it doesn’t require the potentially billions in funding and decades of development needed for the risky asteroid mining venture recently proposed by Planetary Resources, Inc.

If a potentially dangerous asteroid is ever detected, there could be an international effort from space agencies to deflect it by slamming a large counterweight into it, using a gravity tug, or roping it with giant lasso.

A major component of the Sentinel Mission will be public education and outreach, said Lu. The foundation hopes to work with schools and museums to involve students and members of the public – perhaps through some sort of citizen science project – and help inspire future generations to get into science and engineering. They hope to show people that such a project is possible with the technology at hand.

In addition, data from the telescope will map out the near-Earth environ, potentially aiding in future exploration, robotic or manned.

“That’s why this isn’t a fear-mongering message,” said Lu, “It’s an empowering message – let’s just go it.”

Images: 1) The proposed orbit of the B612 Foundation’s Sentinel telescope, which will search for hazardous near-Earth asteroids. 2) Mock up of the telescope’s design. B612 Foundation
Click to expand...
 
Vital eye for killer asteroids could shut imminently
http://www.newscientist.com/article/mg2 ... ently.html
06 July 2012 by Ker Than
Magazine issue 2872.

A LACK of cash could end the only survey dedicated to searching the southern skies for Earth-grazing comets and asteroids. That would create a blind spot in our global view of objects that could cause significant devastation should they hit Earth.

The Siding Spring Survey uses images from the Siding Spring observatory in Australia as part of the global Catalina Sky Survey, an effort to discover and track potentially dangerous near-Earth objects. Astronomers sift through virtually identical images of the sky, looking for moving objects.

Catalina uses a range of northern hemisphere telescopes - and the Sliding Spring Survey. But in October, Catalina cut off cash to the survey due to growing costs, caused partly by changes in the exchange rate between the Australian and US dollars. That decision was "very difficult", says Steve Larson, who heads Catalina.

Since then, the southern survey has been limping along with temporary funding from the Australian National University in Canberra, but the extension is set to expire at the end of July, says survey operator Rob McNaught.

The leftover building blocks of planets, near-Earth objects orbit the sun in highly elliptical orbits, and sometimes graze or hit Earth. Seeing an asteroid before it hits could save lives by providing time to evacuate a region. "Given the very best circumstances, you can predict an impact to 1 second and 1 kilometre," says McNaught. "There's no other natural disaster that you can do that for."

But without a southern lookout, any object approaching Earth from below 30 degrees latitude would be invisible, says Tim Spahr of the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

That won't be much of a problem for massive objects like the asteroid that wiped out the dinosaurs. These are rare and astronomers estimate they have already found and are tracking 94 per cent of them via software models. The worry is asteroids about 30 metres wide, which could flatten a city. Such a hit is blamed for the Tunguska event in 1908, which levelled a 2000-square-kilometre swathe of forest in Siberia.

There are around a million of these smaller objects, making them the most likely to hit Earth, yet locations for less than 1 per cent of them are known. Without a southern telescope, "you could easily get blindsided by one of these", says Don Yeomans, of NASA's Near-Earth Object Program at the Jet Propulsion Laboratory in Pasadena, California. "Whether that's a 1 per cent, 10 per cent or 20 per cent increased risk, I don't know. But it is an increased risk."

What's more, as most asteroids and comets are tracked across both hemispheres, those discovered in the north could get lost without follow-up from the south. There will also be objects seen in the north that could have been spotted sooner in the south, giving more time to prepare.

McNaught estimates that the survey needs about US$180,000 per year, plus a one-off $30,000 to fix the observatory dome. "I really wish I could tell you that the chances are very good that we'll be able to find some money, but I can't," says Harvey Butcher, who heads the team at Australian National University that is providing temporary funding.

If the survey shuts down, there won't be another ground telescope capable of fulfilling its duties until the 2020s, when the Large Synoptic Survey Telescope is due to go online in Chile.

The non-profit B612 Foundation plans to build a space telescope to scan for small asteroids but it won't launch until at least 2017 (see "The people's asteroid defence"). "In the interim, having one eye closed when the cost of having it open is so little seems to be penny wise and pound foolish," says B612 co-founder Russell Schweickart, a former NASA astronaut.

The people's asteroid defence
Citizens, defend thyselves. As governments prove slow at funding telescopes to monitor asteroids, a non-profit organisation plans to pick up the slack - though its telescope won't launch till 2017 at the earliest.

The B612 Foundation - named for the asteroid that was home to the prince in The Little Prince - has announced a plan to build, fly and operate the first private space telescope. Called Sentinel, it will cost several hundred million dollars, which the foundation hopes to raise through donations.

"We think this is eminently doable," says B612's Ed Lu, a former NASA astronaut, who compares the project to funding museums or concert halls. "This telescope will be owned by the people of the world."

Unlike ground-based surveys, Sentinel will orbit the sun, so its view will not be confined to one hemisphere. It will look in infrared wavelengths, so small asteroids that don't reflect much visible light can be seen via their heat. Planned for launch in 2017 or 2018, Lu predicts that Sentinel will find more asteroids in its first month than all previous telescopes combined. Lisa Grossman
Click to expand...
 
Yes, we're all doomed.

Bruce Willis Couldn’t Save Us from Asteroid Doom
http://www.sciencedaily.com/releases/20 ... 101230.htm

Researchers devised a formula to find the total amount of kinetic energy (E) needed in relation to the volume of the asteroid pieces (??r3), their density (?), the clearance radius (R) which was taken as the radius of Earth plus 400 miles, the asteroid’s pre-detonation velocity (?1) and its distance from Earth at the point of detonation (D). (Credit: Image courtesy of University of Leicester)

ScienceDaily (Aug. 7, 2012) — According to the internet hysteria surrounding the ancient Mayan calendar, an asteroid could be on its way to wipe out the world on December 21, 2012. Obviously this is pretty unlikely -- but if an asteroid really is on its way, could we take a cue from the disaster movie Armageddon in order to save the planet?

According to science research carried out by University of Leicester physics students, the answer is definitely "no."

In the 1998 film, Bruce Willis plays an oil-drilling platform engineer who lands on the surface of an Earth-bound asteroid, drills to the centre and detonates a nuclear weapon, splitting the asteroid in half.

The two pieces of the asteroid then pass either side of Earth, saving the planet's population from annihilation.

But the group of four MPhys students worked out that this method would not work, as we simply do not have a bomb powerful enough.

Students Ben Hall, Gregory Brown, Ashley Back and Stuart Turner found that the device would need to be about a billion times stronger than the biggest bomb ever detonated on Earth -- the Soviet Union's 50 megaton hydrogen bomb "Big Ivan" -- in order to save the world from a similar sized asteroid.

To do this, they devised a formula to find the total amount of kinetic energy (E) needed in relation to the volume of the asteroid pieces (??r3), their density (?), the clearance radius (R) which was taken as the radius of Earth plus 400 miles, the asteroid's pre-detonation velocity (?1) and its distance from Earth at the point of detonation (D).

Using the measurements and properties of the asteroid as stated in the film, the formula revealed that 800 trillion terajoules of energy would be required to split the asteroid in two with both pieces clearing the planet. However, the total energy output of "Big Ivan" only comes to 418,000 terajoules.

In other words, we would need to construct a bomb about a billion times stronger than the most powerful weapon ever built in order to save the world in this way.

They also found that scientists would have to detect the asteroid much earlier if we were to have any chance of splitting the asteroid in time.

On top of this, the asteroid would need to be split at almost the exact point that it could feasibly be detected at 8 billion miles.

This would leave no time for Bruce to travel to the asteroid and drill into its centre -- let alone share any meaningful moments with Ben Affleck or Liv Tyler along the way.

Student Ben Hall, 22, from Haverhill, near Cambridge, said: "One possible alternative method would be moving the asteroid via propulsion methods attached to it. What is certain is that most methods would require very early detection of such an asteroid and very careful planning in deriving a solution.

"I really enjoyed the film Armageddon and up until recently never really considered the plausibility in the science behind the movie. But after watching it back I found myself being more sceptical about the film in many areas.

"I think that directors attempt to make films scientifically-accurate but find that a lot of trouble is run into in what can and cannot be done, thus leading to falsification in the science to make movies more interesting or visually appealing to the audience.

The science papers, entitled Could Bruce Willis Save the World? and Could Bruce Willis Predict the End of the World? were published in this year's University of Leicester Journal of Special Physics Topics.

The journal is published every year, and features original short papers written by students in the final year of their four-year Master of Physics degree.

Ben, who graduated with a First last month and is due to start working at Coalville-based optical technology company Zeeko in August, added: "The module was great fun to be involved with as it allowed for us to get our creative juices flowing and attack original problems from different angles. The whole publishing and reviewing process also gave us a very good taster of what it is like to publish papers in the 'real world' as well as being a good simulation of the problems that arise when doing so."

The other three group members also graduated with Firsts, and are set to start PhDs.

Course leader Dr Mervyn Roy, a lecturer at the University's Department of Physics and Astronomy, said: "A lot of the papers published in the Journal are on subjects that are amusing, topical, or a bit off-the-wall. Our fourth years are nothing if not creative! But, to be a research physicist -- in industry or academia -- you need to show some imagination, to think outside the box, and this is certainly something that the module allows our students to practice.

"Most of our masters students hope to go on to careers in research where a lot of their time will be taken up with scientific publishing -- writing and submitting papers, and writing and responding to referee reports.

"This is another area where the module really helps. Because Physics Special Topics is run exactly like a professional journal, the students get the chance to develop all the skills they will need when dealing with high profile journals like Nature or Science later on in life."

Story Source:

The above story is reprinted from materials provided by University of Leicester.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal References:

Back A, Brown G, Hall B and Turner S. Could Bruce Willis Save the World? Journal of Physics Special Topics, November 1st, 2011

Back A, Brown G, Hall B, Turner S. Could Bruce Willis Predict the End of the World? Journal of Physics Special Topics, 2011
Click to expand...
 
Whoa! Earth gets close shave by newfound asteroid

A newfound asteroid gave Earth a close shave early today, zipping between our planet and the moon just two days after astronomers first spotted it.

The near-Earth asteroid 2012 XE54, which was discovered Sunday, came within 140,000 miles (230,000 kilometers) of our planet at about 5 a.m. EST Tuesday, researchers said. For comparison, the moon orbits Earth at an average distance of 240,000 miles or so (386,000 km).

Astronomers estimate that 2012 XE54 is about 120 feet (36 meters) wide — big enough to cause substantial damage if it slams into Earth someday. An object of similar size flattened 800 square miles (2,000 square km) of forest when it exploded above Siberia's Podkamennaya Tunguska River in 1908.

Asteroid 2012 XE54 also passed through Earth's shadow a few hours before its closest approach, generating an eclipse on the space rock's surface, researchers said. [ Video: Asteroid 2012 XE54 Flies Closer Than Moon ]
Click to expand...

http://www.msnbc.msn.com/id/50165912/ns ... MlMxax5ocs
 
140,000 ton asteroid set to narrowly miss Earth in February

140,000 ton asteroid set to narrowly miss Earth in February may destroy SATELLITES... and it could hit us for real in 2020

By Daily Mail Reporter

PUBLISHED: 05:57 GMT, 19 May 2012 | UPDATED: 06:45 GMT, 19 May 2012

* Comments (84)
* Share


A newly discovered 150-foot-wide asteroid may come so close to the Earth in February that it might hit communications satellites.

Discovered by astronomers at the LaSagra Observatory in Spain, 2012 DA14 is estimated to veer near enough to Earth to potentially disrupt geosynchronous satellites on February 15, 2013.

And while NASA have said the chance of the asteroid hitting Earth is 0.031 percent, if it did it would hit with the force of a 2.4 megaton explosion, similar to the mysterious Tunguska event of 1908 which leveled hundreds of square miles of Siberian forest.
The path of 2012 DA14 as projected through February 15, 2013 shows the asteroid falling inside the orbit of geosynchronous satellites

The path of 2012 DA14 as projected through February 15, 2013 shows the asteroid falling inside the orbit of geosynchronous satellites

It is not expected that the path of 2012 DA14 will come anywhere near to hitting Earth in 2013, but scientists have added it to the list of near-Earth objects to examine for its flypast in 2020

It is not expected that the path of 2012 DA14 will come anywhere near to hitting Earth in 2013, but scientists have added it to the list of near-Earth objects to examine for its flypast in 2020

At the moment, the exact orbital path of the asteroid is being determined by NASA and astronomers are erring on the side of caution in case it does come in contact with a satellite.

'That's very unlikely, but we can't rule it out,' said Paul Chodas, a planetary astronomer at NASA's Jet Propulsion Laboratory (JPL) in Pasadena California.


More...

* Mars, Jupiter or an asteroid hurtling through space? These alien landscapes are in fact found on EARTH
* Caught on CCTV: The moment meteorite crashed to earth (and was picked up by this florist in Redcar!)

While the the asteroid is currently a 'fuzzy little blob', as seen through telescopes, 2012 DA14 may eventually come to pass 21,000 miles away from the Earth putting synchronous satellites in the firing line.

'The orbit for 2012 DA14 is currently very Earth-like, which means it will be very close to Earth on a regular basis,' said Chodas.
2012 DA14 will pass so close that astronomers will be able to observe it with a telescope, but even though satellites might be in danger, the International Space Station is not

2012 DA14 will pass so close that astronomers will be able to observe it with a telescope, but even though satellites might be in danger, the International Space Station is not

In the preceding months to February, NASA will try to form a fuller picture of where and how close the satellite will get.

'We don't know exactly where it is, and that uncertainty maps through to an uncertainty in the orbit and predictions,' said Steven Chesley, who also works at JPL.

But for now, no one at NASA is worried that the asteroid will hit but say that 2012 DA14 might be visible from Earth as it flies past.

'It might be visible to people with good binoculars or a small telescope,' said Chodas.
Even if 2012 DA14 did hit Earth it would not cause any long term damage to civilization but would cause massive loss of life if it hit a populated centre

Even if 2012 DA14 did hit Earth it would not cause any long term damage to civilization but would cause massive loss of life if it hit a populated centre

'For such a small object, that's really unusual.'

While astronomers examine their initial estimate of a 0.031 percent chance of 2012 DA14 hitting earth, they cannot rule out the possibility of it hitting in 2020 on its next fly-pass.

That is because they will have to see how close 2012 DA14 gets to Earth in February and how much our gravitational pull affects its course for its next fly by in 2020.

If it does hit, scientist believe that its south-bound approach mean that it will hit Antarctica or the Southern Ocean.
In 1908 an unkown object from space caused hundreds of square miles of forest to flatten in Tunguska in Siberia and it is thought that similar damage would be wreaked by 2012 DA14 if it did hit in 2020

In 1908 an unkown object from space caused hundreds of square miles of forest to flatten in Tunguska in Siberia and it is thought that similar damage would be wreaked by 2012 DA14 if it did hit in 2020

The detonation of the 140,000 ton rock would not end civilization but would potentially cause massive loss of life if it hit a populated centre.

In 1908 it is believed that a comet of an asteroid exploded in the skies above Tunguska in Siberia, causing trees for hundreds of square miles to flatten horizontally.

Regardless of any future dangers, NASA agree that it is good to locate these potential dangers, so that we can add 2012 DA14 to the list of near-Earth asteroids.

'We're now on top of it,' said Chelsey.

Read more: http://www.dailymail.co.uk/sciencetech/ ... z2H2lr3KUZ
Follow us: @MailOnline on Twitter | DailyMail on Facebook
Click to expand...

Edit: A video from CNN about the asteroid:
http://edition.cnn.com/video/#/vide...s-asteroid-near-earth-miss.cnn?iref=allsearch
 
As usual, meejah reports don't answer the obvious questions people like me would ask.

Yes, passing closer than the geostationary satellite distance is very close, but will 2012 DA14 be travelling in the same plane as those satellites? (That is, in the earth's equatorial plane?) If not, it can only pass through that plane at one point near the earth, and that point probably won't be actually at the geostationary satellite distance, so a satellite collision is all but impossible.

Still, with this encounter, and at least two comets to come, 2013 is shaping up to be a very interesting year!
 
rynner2 said:
..but will 2012 DA14 be travelling in the same plane as those satellites? (That is, in the earth's equatorial plane?) If not, it can only pass through that plane at one point near the earth, and that point probably won't be actually at the geostationary satellite distance, so a satellite collision is all but impossible.
Click to expand...
According to this graphic,
http://en.es-static.us/upl/2012/03/2012_DA14.jpeg
a collision would be impossible.

(But I can't now find where I sourced the graphic!

And the graphic raises another question - will the asteroid be visible at closest approach, or will it be hidden in the shadow of the Earth?)
 
Good find, Rynner - that's a relief...
 
Mythopoeika said:
Good find, Rynner - that's a relief...
Click to expand...

Still, plenty of dumb people arond who'll buy insurance in case it hits their house.
 
rynner2 said:
And the graphic raises another question - will the asteroid be visible at closest approach, or will it be hidden in the shadow of the Earth?)
Click to expand...
The cone of the Earth's shadow is a very small target, even at 21000 miles; the asteroid is unlikely to be eclipsed, and wouldn't necessarily be in eclipse for long.

The eclipse need not occur at closest approach, either.
 
eburacum said:
rynner2 said:
And the graphic raises another question - will the asteroid be visible at closest approach, or will it be hidden in the shadow of the Earth?)
Click to expand...
The cone of the Earth's shadow is a very small target, even at 21000 miles; the asteroid is unlikely to be eclipsed, and wouldn't necessarily be in eclipse for long.

The eclipse need not occur at closest approach, either.
Click to expand...
The cone is big enough to put the moon into total eclipse, and the moon is about 240,000 miles out! So inside the geostationary ring the cone would be many times bigger than the moon's diameter!

Even so, any asteroid eclipse would be relatively brief, as the asteroid is travelling so fast (much faster than the Moon). According to the timings on the graphic http://en.es-static.us/upl/2012/03/2012_DA14.jpeg an eyeball estimate has it inside the geostationary ring for maybe less than an hour, and if it does go into Earth's shadow, I'd guess it would only be for maybe 10 or 15 minutes maximum.

But no doubt the experts are continually refining their calculations, and we'll hear more details nearer the time!
 
rynner2 said:
rynner2 said:
..but will 2012 DA14 be travelling in the same plane as those satellites? (That is, in the earth's equatorial plane?) If not, it can only pass through that plane at one point near the earth, and that point probably won't be actually at the geostationary satellite distance, so a satellite collision is all but impossible.
Click to expand...
According to this graphic,
http://en.es-static.us/upl/2012/03/2012_DA14.jpeg
a collision would be impossible.

(But I can't now find where I sourced the graphic!

And the graphic raises another question - will the asteroid be visible at closest approach, or will it be hidden in the shadow of the Earth?)
Click to expand...

The graphic is from http://neo.jpl.nasa.gov/news/news174.html
 
Nasa: 2012 DA14 asteroid 'will not impact Earth'
An asteroid measuring 150 ft (45 m) across will whizz past Earth just 28,000km (17,000 miles) above the equator a week on Friday – a record close approach for an object of its size.
[video]
9:57PM GMT 07 Feb 2013

The 130,000 tonne space rock will miss Earth so narrowly that it will come within the orbit of some communication satellites, travelling at a speed of five miles per second – eight times the speed of a bullet from a rifle.

Although smaller asteroids have made even closer approaches the close shave, which will peak at about a thirteenth of the distance to the moon, will be the nearest for such a large object since records began.

Donald Yeomans, manager of the near-Earth object office at the Jet Propulsion Laboratory in California, said in a press conference on Thursday: "This asteroid's orbit is so well known that we can say with confidence it can pass no closer than 17,100 miles from Earth's surface, so no Earth impact is possible."

In a separate animated video showing the asteroid's projected path, published on the Nasa website, Mr Yeomans also assured viewers that the space agency was tracking the threat of stray asteroids "100 years into the future".

http://www.telegraph.co.uk/science/spac ... Earth.html

I've corrected the sub heading to match the size given by Wiki:
http://en.wikipedia.org/wiki/2012_DA14
It is now known that on February 15, 2013 at 19:25 Universal Time the asteroid will pass at a distance of 0.000228 AU (34,100 km; 21,200 mi) from the center-point of Earth,[2] with an uncertainty region of about 0.000001 AU (150 km; 93 mi).[2] (In other words, the asteroid will pass about 27,700 kilometers (17,200 mi) above Earth's surface.)[6]

The asteroid will pass closer than satellites in geosynchronous orbit.[6] The asteroid will not be visible to the naked eye,[8] but will briefly peak at roughly apparent magnitude 7.4.[9] The best viewing location for the closest approach will be Indonesia.[6] Eastern Europe, Asia and Australia are also well situated to see the asteroid around its closest approach.
Click to expand...
 
If it does take out a couple of satellites, we'll have a virtually impenetrable curtain of debris shrapnel orbiting earth with each particle having the damage capability of a high-velocity bullet.

Visiting UFOs should be advised to divert more power to the shields.
 
jimv1 said:
If it does take out a couple of satellites, we'll have a virtually impenetrable curtain of debris shrapnel orbiting earth with each particle having the damage capability of a high-velocity bullet.
Click to expand...
It wouldn't be as bad as that. I could be that the satellite just goes SPLAT! on the surface of the asteroid and is never seen again!

In the case of a glancing collision which fragments the satellite, each fragment would follow its own orbit, and many of them would hit the atmosphere and burn up. Some might achieve escape velocity, and leave the Earth for ever.

Those that do remain in orbit will be rapidly dipersed over a large volume, and although geostationary comms satellites are large, space is much larger, so there's no chance of an "impenetrable curtain of debris shrapnel" being formed.

There is one 'danger point' that might need to be considered, however, the position of the original satellite, because orbital dynamics decrees that the fragments, on their individual orbits, will intersect the original orbit again at that point. But they won't all bunch up there at the same time, because the period of each fragment will be different - they would pass at intervals of hours or days, the swarm getting less and less dense with time.

And over time various gravitational perturbations of the fragments' orbits, plus the effects of radiation pressure, would drift them away into an even more diffuse cloud. (Geostationary satellites have to carry fuel to maintain their positions because of these perturbations.
http://en.wikipedia.org/wiki/Geosynchro ... nary_orbit )

Fragments with a low perigee orbit could be perturbed enough to touch the outer atmosphere, and the orbit would then decay until the fragment enters the denser atmosphere and burns up.

Eventually the average density of the fragments in space would drop to that of the ever present solar system meteoroids.
 
I prefer my more fanciful version.

- Which is backed up by the fact that bits of debris less than 1cm across are hurtling around earth at a speed of 25,000 km/h.
In a section on Stargazing Live, they showed the casing of a satellite which had tiny holes punched right through by specks of grit.
And this clip shows how a shuttle windscreen was almost taken out by a tiny chip of paint.

http://www.youtube.com/watch?v=i-Oizlqhajk
 
According to alternative news sites the 2012 DA14 asteroid will pass as close as 14000 miles to the earth.

Asteroid 2012 DA14 Will Pass Within 14,000 Miles Of Earth On February 15, 2013
October 29, 2012
Share

International leaders in asteroid and comet research are gathering at the University of Central Florida in Orlando Friday, Feb. 15, for a special “viewing party” that will climax with asteroid 2012 DA14 zipping between Earth and orbiting communication satellites (within 14,000 miles of Earth).

The asteroid, the size of a city block, will squeeze by Earth’s atmosphere and the geostationary satellites orbiting the planet. It will be the closest fly by in history.


Watch Video



Experts say there is no chance the asteroid will hit Earth — this time. But with more than 4,700 asteroids NASA has identified as potential threats to Earth, some as big as 16 football fields, these objects are getting a lot of attention.

Humberto Campins, a UCF physics professor who led the first team to discover water ice on an asteroid in 2010, says the asteroids provide clues to the early formation of the solar system and should interest the entire community because they can be hazards as well as resources.

Campins is working on NASA and European Space Agency missions launching in the next few years to recover asteroid samples

Should an asteroid be detected on a collision course with Earth, it will be critical to know its composition and structure in order to deflect it. The impact of a small asteroid like DA14 would equal the destructive power of an atomic bomb. A larger asteroid could be catastrophic.

That’s why Campins and the planetary scientists at UCF organized this free viewing party and invited leaders in asteroid research to speak to the public about the reality and myths of these ancient rocks on Feb. 15. UCF and the Florida Space Institute are sponsoring this event.

Asteroid 2012 DA14 will pass closest on February 15, 2013. As the image above shows, it will pass much closer than the orbit of the moon – closer even that orbiting geosynchronous satellites (22,000 miles). Image Credit: NASA

Confirmed speakers include Dr. Michael F. A’Hearn, the scientist who led NASA’s Deep Impact mission, which launched the first man-made object into the nucleus of a comet, and Dr. Harold Reitsema, a former NASA scientist who is part of the B612 Foundation’s (http://b612foundation.org) private effort to launch a telescope that will locate and track asteroids that could hit Earth. The scientists will talk about why asteroid research is so vital to Earth and the new NASA and private efforts to track them.

The public also will get a chance to see the fly-by through exclusive live feeds from telescopes in La Sagra and Tenerife, Spain, where the astronomers who first discovered DA14 will be tracking it. Live feeds from Majorca and other observatories are also planned. Astrophysicist and asteroid expert Dr. Javier Licandro, of the Institute of Astrophysics of the Canaries in Tenerife, Spain, also will provide some commentary. Licandro and Campins regularly collaborate on research projects.

Members of the media are invited to attend UCF’s Asteroid Viewing Party from 12 noon to 3:30 p.m. EST on Feb. 15. Save the date and visit http://news.cos.ucf.edu beginning Nov. 15 for details and to register.

Read more: http://mwvastronomy.net/2012/10/asteroi ... z2KUXwJifY
Click to expand...
 
"The size of a city block"? Really? What city is that - Legoland? Someone has stuck an extra zero on this 40m chunk of rock, I fear.
 
You must log in or register to reply here.
Back
Top