The Voyager records - they were almost blank

I think, on occasion, of the Voyager probes. The universe is almost completely empty -- and becoming emptier as dark energy inflates our universe. The probes will likely sail, alone, for as ever as ever is. For uncountable years they will have attached to them a vestige of the most unusual LP ever pressed.

What I didn't know, until I read the account of the man who made the record, was that a NASA bureaucrat almost mounted a blank disc on the side of the probes....

The Mix Tape of the Gods - New York Times

... the astronomers Carl Sagan and Frank Drake persuaded NASA to attach a gold-plated phonograph record to each of the Voyager spacecraft.

Containing photographs, natural sounds of Earth and 90 minutes of music from all over our world, the record was intended to preserve something of human culture beyond what an intelligent extraterrestrial, encountering the craft at some far-distant time and place, might infer from the spacecraft itself.

The information etched into the grooves of the Voyager record is expected to last at least one billion years. ..

... after the record was completed, NASA rejected it on technical grounds. Late one night in a New York sound studio, when we’d finished cutting the master, I inscribed the words, “To the makers of music — all worlds, all times,” in the “takeout grooves” next to the label. (The Voyager record is a metal version of the 33 1/3 vinyl records of the day, recorded at half-speed to double its data content. Etching an inscription between the takeout grooves was a trope I’d picked up from John Lennon.) A NASA quality-control officer checked the record against specifications and found that while the record’s size, weight, composition and magnetic properties were all in order, its blueprints made no provision for an inscription.

So the record was rejected as a nonstandard part, and the space agency prepared to replace it with a blank disc. Sagan had to persuade the NASA administrator to sign a waiver before the record could fly...

It is astonishingly unlikely that any sentient being will ever touch those records. As far as we know we are alone, and even if another technologic society develops somewhere it's hard to imagine a technology that could detect one of the long-silent Voyager probes passing through a star system (ok, nanites infesting the entire peri-solar region?). It is very likely, however, that those records will endure long after every remnant of humanity has passed on.

NBC plugs the family loophole in Digital Rights Management

Daring Fireball points out where NBC is going with its DRM:

Daring Fireball

This just shows how moronic these NBC clowns are. You don’t have to be a nerd or obsessive to see how these restrictions suck — they’re obvious. No mixing means you and your spouse can’t both buy material for each other’s use.

All of our music is on one server, regardless of whether my wife bought it or a I bought it. Some predates our marriage, most does not. NBC doesn't like this. They want only one person to have rights to any media.

DF doesn't mention, however, that while iTunes does not forbid mixing, neither does Apple encourage it. Many iTunes related features don't work if two people sync to one repository. Most people don't notice this when they use an iPod, but wait until both use an iPhone. They'll discover that they need to be in their own user account when they sync, and that means they won't have easy access to a shared music library any more. Apple is not so much virtuous as subtle. NBC is merely stupid. From my post of November 2005 ...

... How best to understand this? Think of the secret and forbidden lust of the media companies -- the (patent pending 2040) BrainLock™ (Palladium Inside!™). The BrainLock™ prevents any access to DRMd material by control of visual, auditory, tactile, and olfactory inputs. BrainLock Enhanced™ (mandatory upgrade 2045) makes it impossible to consider any action that would circumvent the workings of the BrainLock™ (thereby ending the trickle of death sentences related to violations of the DMCA amendment of 2043).

Really, the idea of "shared property" is a legacy of ancient law related to the fading practice of marriage. The media companies abhore this idea. Each person should own their own BrainLocked™ media (ok, just biometric locked until the advantages of BrainLock™ associated enhancements become irresistible). If you and your multiple spouses and myriad children want to listen to music, you each need your own music stream. Joint access is discouraged, though it will not be effectively blocked for some time.

The bottom line is that Apple's media partners really don't want multiple users accessing a single iTunes repository. They can't do anything about multiple iPods for now (after all, a single user might have an iPod and a Nano!), but they accept that grudgingly. They won't allow anything to encourage multiple iPods with multiple users, and that means this "design problem" isn't going to get fixed -- because it's working as designed.

Crummy results on Google searches? Their defenses have failed

I've been reading Matt Cutts for over a year. If you read him, you think Google has strong defenses against vendors who game their rankings. On the other hand, some searches persistently produce large numbers of garbage results. This doesn't add up. 

That's why I believe this post is credible (read the entire post for the full context):

Gaming Google - It Really Is That Easy...

... I was one of those people who looked down on buying links for a long time. It just seemed wrong – and surely the brain trust at Google would clamp down at some point. I just couldn’t believe that buying your way to the top of the organic results could A) be SO easy, or B) yield sustainable results. That was three years ago.

This scheme of embedding links in free stat counters in order to juice link pop has been around for at least that long – and should be among the easiest for Google to detect. It should be a big yellow flag when a site gets lots of inbound links from totally unrelated sites over a short time period. And it should be really easy to detect the code pattern like the one shown above for those inbound links (it even says “invisible" for God’s sake!). Finally, it is pretty irregular to have a UK page show up at the top of the results for a competitive term like this on Google.com. It seems like that might have thrown a flag somewhere along the line as well. The patterns are easy to spot. But Google is either oblivious to all of these issues or they’ve decided not to do anything about it. I’m not sure which is worse...

Google's defenses aren't working. I know they're having problems delivering almost across the board (Gmail still works well at least!) but this has got to be their number one problem.

An insider geek comes clean on the chaotic nature of emergent financial instruments

I've not yet read the entire first chapter Big Picture has excerpted, but this is quite remarkable. A geek insider (MIT? Geek.) is telling tales about the complex and recursive financial instruments that have emerged over the past decade...

The Big Picture | A Demon of Our Own Design (Richard Bookstaber)

While it is not strictly true that I caused the two great financial crises of the late twentieth century—the 1987 stock market crash and the Long-Term Capital Management (LTCM) hedge fund debacle 11 years later—let’s just say I was in the vicinity. If Wall Street is the economy’s powerhouse, I was definitely one of the guys fiddling with the controls. My actions seemed insignificant at the time, and certainly the consequences were unintended. You don’t deliberately obliterate hundreds of billions of dollars of investor money. And that is at the heart of this book—it is going to happen again. The financial markets that we have constructed are now so complex, and the speed of transactions so fast, that apparently isolated actions and even minor events can have catastrophic consequences.

My path to these disasters was more or less happenstance. Shortly after I completed my doctorate in economics at the Massachusetts Institute of Technology and quietly nestled into the academic world, my area of interest—option theory—became the center of a Wall Street revolution. The Street became enamored of quants, people who can build financial products and trading models by combining brainiac-level mathematics with massive computing power. In 1984 I was persuaded to join what would turn out to be an unending stream of academics who headed to New York City to quench the thirst for quantitative talent. On Wall Street, too, my initial focus was research, but with the emergence of derivatives, a financial construct of infinite variations, I got my nose out of the data and started developing and trading these new products, which are designed to offset risk. Later, I managed firmwide risk at Morgan Stanley and then at Salomon Brothers. It was at Morgan that I participated in knocking the legs out from under the market in October 1987 and at Solly that I helped to start things rolling in the LTCM crisis in 1998.

One of my blog posts in waiting is about the vast array of memes arising in the science fiction of the past decade. I can't sort out who contributed what (sorry, I didn't have that kind of memory even when my brain worked), but I recall one author recently tossing off the meme of "Finance 2.0"[1], a tongue-in-cheek portrayal of cyber super-intelligences emerging from the wellspring of financial instruments. I think they attempt to convert the protagonists into cash flow.

I suspect the author is going to tell us that these instruments have evolved beyond our ability to understand them, much less predict their behavior under stress, and that given the extremely rapid pace of their evolution they are likely to have chaotic behaviors. Should be a best seller!

[1] Update 11/20/2010: Charles Stross, Accelerando -- and it was "Economics 2.0", not "Finance 2.0"

"Fake Steve": The problem with Web 2.0 software development

"Fake Steve", we now know, is a Forbes journalist writing as a cartoon of Steve Jobs. It's often funny, but the tone has changed since he's been exposed. Over the weekend for example, he had to censor an article that went a bit over the edge for Forbes (I suspect it was the "estrogen" comment about a female NBC board member and Cisco CEO.)

On the other hand, even as he has to be a bit more careful, he can also be a bit more insightful. In a fake rant about Microsoft's puff piece in the NYT (the NYT piece was a nice bit of marketing, as Fake Steve admits with fake envy) he has some things to say about web 2.0 development that strike me as mostly true (emphases mine):

The Secret Diary of Steve Jobs: Another big sloppy wet kiss for the Borg

... Trust me on this. Nothing in Windows Live will work the way they say it will. And when you complain they'll tell you the problem isn't with Windows Live, that the system works fine, that people are loving it, that the acceptance has been amazing, better than they projected, subscriber rates are the fastest they've ever seen, and if you've got problems it must be because you're doing something wrong or maybe it's the version of Windows you're using and have you installed the latest Service Pack and maybe you should connect in with your computer so the Borgtards can verify that the software on your PC is legal and authorized and paid-for because probably you're a software pirate or you've installed the software on too many PCs and you need to buy a new copy of Vista.

Or maybe you'll just go online trying to find help so you can fix things yourself. And when you do you'll find some brain-dead "knowledge base" with mind-numbing instructions that turn out, even after you've read them, not to make any sense, because the people who wrote the FAQs were describing an earlier version of the software, or simply weren't paying attention, or were as pissed off and confused as you are after realizing that in fact the software actually doesn't fucking work, or worse yet, they were just bored and underpaid and decided it would be fun to fuck with your head by giving you instructions that nobody can understand. Maybe they have competitions to see who can be the most inscrutable. I don't know.

One thing I do know is how the Borg develops software. Imagine a hundred separate teams of Keebler elves all smoking crack and then being told to sit down in different parts of the world, without being able to communicate with each other, and dream up new cookie flavors, and you've got an idea how the Borg created Windows Live. Then a bunch of generic, soulless, humorless lab-produced MBA replicants (photo) who don't know anything about technology and only went to Microsoft because they didn't get offers from Procter and Gamble are put into a conference room and told to create some marketing plan for this pile of dog shit. Dream up a slogan and a name and some advertisements that will mislead people into thinking that Windows Live is all one big wonderful suite of software that was developed from the ground up to work as an organic whole, even though the pieces are all being rolled out at different times in different locations on different websites...

He's writing about the Borg (Microsoft, of course) here, but this is increasingly true for Google (except the marketing plan part, they don't bother with that) and has always been true for Yahoo!. Web 2.0 software development feels like a mess to gomers like me who expect things to work, and to have a bit of documentation on how they're supposed to work. Grumph.

BTW, there are parts of Windows Live that I really like. Windows Live Writer has nothing to do with web 2.0 (it's a traditional desktop application!) but it's fabulous. Windows Live Desktop Search (Vista style search for XP) is terrific -- but it's a desktop application too. As to the web 2.0 portions of "live" ... well .... no.

Answering the question and more: "why are so many nerds libertarians"

Someone asked Slashdot why geeks are more often libertarian than liberal.

Slashdot | Why Are So Many Nerds Libertarians?

...Why do so many nerds seem to lean toward the Libertarian end of the spectrum?

As a leftist, I know there are many people who share my ideological views, but have very little in common with me in terms of profession and non-work interests...

I scanned the responses, but as expected for this type of Slashdot question I didn't see anything interesting. One part of the answer is the questioner's friends are young and think themselves strong. Many are fair weather Libertarian in other words. If they feel the same way when they are weak (for if they live, they will be weak sometimes), or when those they love are weak, then they will be true Libertarians.

A more serious response to the question begins by clarifying the distinction between a Liberal and a Libertarian. The meanings of these terms changes from year to year, but I propose, since this is my blog post, to use two questions to make the distinction:

(sorry for the rendering, tables really don't work on Blogger.)

Should society require the strong to aid the weak?	Y	N**	N	Y
Should Reason overrule Belief and Tradition?	Y	Y	N	N
Results:	Liberal	Libertarian	Conservative	Other*

* A mixed bag, includes populists, many Greens, many religious persons, some 1970s style liberals, Luddites, Naderites, communists, the average voter, and the rare genuine "compassionate conservative".

** A libertarian might personally choose to aid the weak, but they would never support a social requirement to do so. That would be a constraint of liberty.

In terms of political party Liberals almost always vote Democrat, Conservatives almost always vote GOP, and the rest are less predictable.

If one accepts this division, then a Rationalist may be Liberal or Libertarian, but never Conservative. Since Libertarians may vote GOP, not all Rationalists need vote Democrat. Since geeks are almost entirely Rationalists, the Slashdot question may be rephrased: "Why should the strong aid the weak"?

The answer turns into a discussion of Ethics and Mores, about which much has been written, but I think there are three ways to justify aid to the weak:

1. Self-preservation: If the weak are many, then they become strong by virtue of numbers. It may be most unwise to deny them aid when that can be provided. This is also known as "keep the rabble from storming the castle"; it is used (by Sachs and others) as a justification for aid to more miserable parts of Africa. (Incidentally, in ratings of optimism the average African is quite optimistic about his/her future -- more so than the average American.)
   


2. Self-interest: One may be strong now, but weak tomorrow. Those one loves may be weak or become weak. Aid to the weak may be a form of insurance.
   
   
3. Aesthetics, guilt, compassion, a reason for existence, noblesse oblige, anger at the universe, socialization: One may choose, for a mixture of all these reasons, to help the weak.
   

If by one or more of these justifications one feels it is wise or right to aid the weak, then the next question is whether one should make this a social obligation as well. That is a longer discussion, but in practice free-rider problems mean that these obligations most often become social rather than remain personal.

I think most Rationalists who think about these questions end up more often Liberal than Libertarian (though perhaps not until their late 30s), but I can respect the Rationalist Libertarian -- particularly if the Libertarian is in practice compassionate, of if they retain their principals of ignoring the weak when they themselves become weak.

The end of the flash?

A half-decent flash for a dSLR costs about $240 now (it used to cost about $400). That's a significant fraction of the cost of a low end dSLR.

On the other hand, the newest pro Nikon CMOS based camera has a maximal ISO of about 24,000. We can reasonably expect entry level dSLRs to have similar light sensitivity within 3 years -- if Nikon or Canon resist then SONY will force the issue.

I assume the 24K ISO on that pro Nikon is extremely noisy, but I'm guessing the 2K ISO isn't bad. With an ISO of 2K only specialists will need to use a flash.

I wonder when the prices will really start to fall? Probably when the used, but still quite good, flashes start to flood the market.

UPS crushes another Amazon.com package

Lately, UPS has been at mangling every other package they deliver, but this time they went too far:

Geez, it was my son's end-of-summer $20 Lego kit for Pete's sake. I'm seriously annoyed with UPS, but I seriously doubt it would help to complain to them. They know they have a problem, and either they can't fix it or they don't care. Either way, my complaining to UPS is a waste of time.

On the other hand, Amazon has clout. They can threaten to start using the USPS (which does a better job with my packages) - for example. UPS is making Amazon look bad, and if this goes on I'll start shopping locally. So I wrote to Amazon instead:

Once again UPS has crushed an Amazon.com package. This one contained a gift for my son, the side of the box is also crushed.

After he opens it tonight we'll see how bad the internal damage is and decide if we want to return in it. In the meantime, I'm very unhappy with UPS, and that means I'm unhappy with Amazon.

I'm pretty sure I got this one "free shipping", but "crushed" is a negative benefit. I'd be glad to send you copies of the pictures I'll be taking of the box and the enclosed item. At this point I'd like you to:

1. Send me a gift certificate for $10 as compensation.

2. Tell me you know that this is a real problem and let me know what Amazon is going to do about UPS. They're an increasingly dysfunctional business partner of yours and they're making you look bad.

Amazon wrote back, in a somewhat confused email that looked like a cut and paste job -- but here's the cleaned up version ...

I am sorry to hear that you have received the damaged item ...

I sincerely apologize for any disappointment you have experienced
with this order.

We are aware that our choice of delivery services reflects on our business as a whole, and we appreciate your feedback.

I have passed your message along to our shipping department, as I know they will want to read about your experience.

Rest assured your feedback has certainly not fallen on deaf ears, and has been shown to all appropriate personnel who would benefit from it. We do take suggestions from our customers very seriously and are grateful for your insights.

Based on the condition in which the item ... arrived, we are offering to refund 30%
of the purchase price of this item...

Lego kits are typically very loosely packed, and in this case the parts were fine. My son tends to ignore the state of the box, so he was perfectly happy with the gift. I did take the 30% credit though, I want Amazon to feel a bit of pain. Don't worry, they make a ton of money from our household.

Amazon needs to turn up the heat on UPS. The next time UPS delivers a crunched Amazon package, let Amazon know what you think.

An ocean of poisonous fish

You can sustain a population of a few hundred people by hunting, but it doesn't scale to a million people. That's why we had to have agriculture before we could infest the planet. Except, when it comes to fishing, we're still hunter gatherers. Not surprisingly, the fish are going away.

It's unlikely this will continue for more than fifty years of course. Either 8.9 billion people will die or we'll get our house in order. I was wondering, however, how evolution would respond in the impossible event that we stayed around, much as we are now, for a few thousand years. There'd be a large vacant ecological niche in the ocean -- what could possibly fill it?

Poisonous fish, of course. Something we couldn't eat. The ultimate defense against the ultimate predator. In time the ocean would be full of vast varieties of poisonous fish, all inedible.

It won't happen of course, but still, something to contemplate ...

Inline skating? Wear a helmet.

These days, most people wear helmets when bicycling. That's not true of inline skating, but in the thirteen years I've done both with comparable frequency I've had greater need of a helmet on skates than on my bike. (I used to do vastly more bicycling, the current balance is driven by my kids.)

Among experienced inline skaters in Minnesota, I think that about 80% wear a helmet. The frequency of helmet use among novices is much lower -- but they don't move too fast. The real problem is semi-skilled skaters, only about 20% of them wear helmets. They can move quickly.

I suspect Dr. Weinstock was in the 20% of strong skaters who don't wear helmets ...

Popular doctor dies from skating injury: A fall on rollerblades- NJ.com
Tuesday, August 28, 2007
BY ALEX ZDAN and MICHAEL RATCLIFFE

A well-respected opthalmologist died Friday after sustaining injuries in a rollerblading accident in Hopewell Township. Dr. Floyd Weinstock, 53, apparently fell while in- line skating Thursday afternoon, suffering a severe head injury, police said...

Life is a terminal condition. Inline skating, bicycling with cars, working on a farm, downhill skiing, walking in some cities at night -- all dangerous activities. Yes, but, even so, there's much to be said for evening the odds.

I don't like wearing my helmet when I skate. I understand why Dr. Weinstock didn't want to wear one, but a helmet does even the odds -- and it makes it less likely your wife will pursue you to the gates of Hell if you do die. Helmets don't make you invulnerable, but they can convert a fatal head injury into a severe concussion, and a severe concussion into a mild concussion.

The worst injury I've had skating was a mild concussion (no loss of consciousness) due to a trivial trip and fall at at walking speed; if you catch a skate so it becomes a pivot point you can get quite a bit of angular velocity six feet from the axis (ie. at the head). I was wearing a helmet of course, and it did what it could do. I like to replace them often now, to keep the foam fresh.

Even the odds. Wear a helmet. Remember Dr. Weinstock. Had I been caught out on a similar mistake, I like to think I could at least become a cautionary tale. I suspect he'd have felt the sam way.

Lessons in limitations: One of government, one of the web

[This wasn't one of my better posts. See the update for the denouement. I'd delete the post, but that isn't playing fair.]

The original:

I picked up a map at the Minnesota State Fair yesterday. It's the DNR's state trail system map. It looks great at first, until one realizes that the Lake Wobegon trail is missing, despite being connected to the Central Lakes Trail (which is included). True, the connection is new, but the real issue is that the Lake Wobegon trail is not a DNR trail, and this is a DNR map.

So the DNR has provided us piece of a map, but not a functional map. It will be valuable to people who write books about bicycle trails in Minnesota, but, really, the DNR shouldn't have bothered with a public distribution. One day Google (or someone) will put together a mapping framework that works, the DNR could own one layer, other organizations could own their layers, and we'd have something useful. For now, we have authors as system integrators who fit the puzzle pieces together.

That's a limitation of government, and, more broadly, of any emergent result (a trail network) arising from multiple contributors. Creating self-integrating emergent systems (wikipedia) is something we're only starting to learn about.

The other limitation, one that's wider than government, is that the web is just too hard for people to get right. In particular, links are too hard. (On a related topic, Apple has abandoned one of their core innovations - file indirection.) The paper map references a URL: http://www.dnr.state.mn.us/state-trails. Yep, you guessed it: "404: Page not found." The DNR reorganized their site, broke the link, and didn't provide a redirect. The father of the web would not be surprised - he'd wanted indirection to be a part of the web infrastructure from the start.

Links are too hard. Maps that are puzzle pieces rather than solutions. Two limitations -- with some common roots.

Update: Ok, so this wasn't one of my better posts.

1. I think the map simply had a typo. The url should have been: http://www.dnr.state.mn.us/state_trails. I've notified the MN DNR of the typo.
2. It's true that the DNR only includes their trails on the map, but their web site has not only a great set of trail PDFs but also has a set of links to other long distance trails in MN. So, really, they're awfully close. They just needed to include those other trails on their overall map and they'd have had a real winner.
3. In addition to authors who put books together on MN trails, the DNR also distributes a magazine called Minnesota Trails. That organization is not limited to one agency, and their magazine includes all the state trails and their web site includes a cross-entity view of trails in MN.

So government isn't doing too badly here, and the link example I used was probably a typo rather than a careless break. Ookkkayy, moving right along ...

The feeding of dog and primate: NYT Magazine's peek into the maze

NYT Magazine 9/2/07: They Eat What We Are reads like an excerpt from a much longer book. It's a small window into a large and complex enterprise - the business of industrial dog food. Mr Kaufman is studiously neutral, and he makes an interesting observation on how diet is diverging. Highly educated middle class diets are becoming "organic" and "natural" -- for both humans and their canine comrades. The other 80% of America is moving to an increasingly processed and industrial diet for both humans and canines, with technologies migrating from one species to another.

Kaufman only touches briefly on the melamine story, though it's obviously in the background.

There's too much here to fit into a NYT Magazine article, but the unacknowledged book should be quite interesting ...

The NYT on Abraham Lincoln. In 1860.

Google has introduced searches of historical archives -- most appear to be from the NYT. Interestingly, they apppear to be OCRd -- not just scans. The average article, like this one, costs $5:

THE COMING ADMINISTRATION.; Views, Opinions, Senti... - Article Preview - The New York Times

THE COMING ADMINISTRATION.; Views, Opinions, Sentiments and Purposes of Abraham Lincoln.HIS POSITION ON SLAVERY.Is he Sectional and Ultra, or Conservative and National? WHAT THE REPUBLICANS MUST DO. HOW MR. LINCOLN REGARDS SOUTHERN MEN. THE REAL ISSUE ON THE SUBJECT OF SLAVERY. HOW REPUBLICANS REGARD THE DRED SCOTT DECISION. THE FUGITINE SLAVE LAW. ADMISSION OF SLAVE STATES. COLUMBIA. DOMESTIC SLAVE-TRADE. WHEN THE SLAVERY QUESTION BECAME OF PARAMOUNT IMPORTANCE. MR. LINCOLN ON THE EQUALITY OF NEGROES AND WHITES. FURTHER STATEMENTS CONCERNING NEGRO EQUALIY. MR. LINCOLN'S VIEWS ON THE SUBJECT OF NEGRO EQUALITY. MR. LINCOLN'S VIEWS ON SLAVERY AND SOUTHERN RIGHTS. PERSONAL.

Since it's OCRd from low quality sources there are a lot of typos and layout errors - as in this excerpt. The quality, of course, will continue to improve. I wonder if Google will introduce wiki-like collaborative editing -- probably not, given the challenge of preventing vandalism.

Headlines are a bit shorter than they used to be. This one is essentially a headline and an outline of the article to come -- probably based on the structure of a book (title and chapter headings).

BBC FAQ on the subprime crash - very readable

The BBC has put together a very readable FAQ about the "meltdown" in the sub-prime mortgage industry and the related bank losses (and wins, but nobody's talking about who's winning - yet). It's the best summary I've seen anywhere. For example ...

BBC NEWS | Business | Q&A: World stock market falls

.... Even if the central banks stem the financial panic, there seems to have been a general shift in market perceptions about risk. Generally, the riskier the investment, the higher the interest rate - but now the additional premium for risky investments (the 'spread') is set to widen sharply. When people with money to lend become worried about risks, they tend to put their money in safe investments. So there has been a rush to invest in government bonds, like US Treasury bonds, and safe currencies, like the dollar. In contrast, people are now demanding much higher interest rates to lend to smaller companies or to the governments of developing countries. Investors have also grown wary of lending to private equity funds who want to buy and sell companies. This may mean that this is much less takeover activity than in the past few years, which could also affect the stock market...

Apophis: mark your calendar for April 2029

If I live, I'll be almost 70 when Apophis flies by. I hope that our orbital calculations are as good as we think they are, I'm looking forward to the show. I recall reading about this in 2004, but I didn't remember that the passage will be so close ...

BBC NEWS | Science/Nature | UK plan to track asteroid threat

.... The 300m-wide (980ft) rock, known as Apophis, will fly past Earth in April 2029 at a distance that is closer than many communications satellites.

Astrium, based in Stevenage, Herts, wants a probe to track the asteroid so its orbit can be better understood.

The concept will compete for a $50,000 (£25,000) Planetary Society prize, but a full mission would cost millions.

The British design calls for a small, remote-sensing spacecraft, dubbed Apex (Apophis Explorer), which could rendezvous with Apophis in January 2014.

It would then spend the next three years tracking the rock, sending data back to Earth about the object's size, shape, spin, composition and temperature.

From this information, orbit modelling would enable a more accurate prediction of the risk of any future collision.

Astrium says that if its concept won the prize, it would donate the money to charity...

... A full mission would be expected to cost about $500m (£250m) dollars to develop, launch and operate.

Apophis caused some consternation in 2004 when initial observations suggested there was an outside chance it might hit Earth in 2029.

Further study by ground-based telescopes indicated there was virtually no possibility of this happening, and the expectation is that the object will whiz past the Earth at a close but comfortable distance of just under 36,000km (22,400 miles).

However, there is always some uncertainty associated with an asteroid's orbit.

One reason is the Yarkovsky effect. This describes what happens when an asteroid radiates energy absorbed from the Sun back into space.

Releasing heat in one direction nudges the object in the opposite direction. The resulting acceleration is tiny, but over the centuries acts like a weak rocket and could make the difference between a hit or a miss in some circumstances.

The close encounter with Earth in 2029 will also perturb Apophis' orbit gravitationally.

A mission like Apex to track and study the rock would help reduce uncertainties and give solid predictions about the rock's course long into the future...

... were such a rock to hit the planet, it could cause devastation on a country-wide scale, leading possibly to the deaths of many millions of people.

An Apophis-like object striking at about 20km/s (45,000mph) would gouge a crater 5km (three miles) wide. Even standing 30km (18 miles) away from the impact site, a thermal blast would ignite your clothes and the ground would shudder with an earthquake measuring more than six on the Richter Scale.

Given sufficient warning, though, a potential impactor could be deflected out of Earth's path, scientists believe.

Some have suggested such a rock might be nudged on to a safe trajectory by hitting it with a small mass. Others have proposed flying a spacecraft next to the object, to use gravity to tug the asteroid clear of the planet....

See also the New York Times, March 2007 for a related discussion focusing on general impact management.