Your time has come!

The message transmitted would be at the speed of light, we can already do that via radio. A far simpler alternative.

They should shoot these "astroboffins" into deep space. Have they bothered to calculate just how much materials are needed?

[back of fag-packet mode]

The moon has a radius of 1900 km giving it a crosssectional area of 3.1416 * 1900 *1900 * 1000000 = 10^13 m2. If the reflective surface is 1mm thick then that is 10^10m3 or 10 billion m3 of metal. If we use Aluminium then we have a mass of 2.7x10^13 kg or 27 billion tonnes of metal

[/back of fag-packet mode]

Also, attracting aliens might not be a good idea - have they ever read "Footfall", "The Mote in God's Eye", "War of the Worlds" or seen "Independence Day"? We can't afford to attract aliens unless Randy Quaid is free - just in case...

Lets tell them EXACTLY where we are then,

On the galatic maps we can replace "Here be dragons" with

"Here be low tech morons ripe for the taking"

Skull and X-Bones cos of space pirates and the fact that Humanity will eventually find a way to wipe ourselves out!!

Yes, because this will be so much more obvious and easier to detect than a radio transmission would be. After all, we all know how much more sensitive optical telescopes are at very long interstellar ranges than radio telescopes and how likely our lunar semaphore flashes are to overtake any radio traffic that's already headed out that way.

They don't call 'em "lunatics" for nothing, you know.....

(I'm now wondering just what an "extreme sarcasm with knobs on" icon would look like were we to have one)

Would heating up the surface of the planet do us any good? Maybe on an uninhabited planet, covering one of it's moons with these mirrors would be a good way of warming up the surface, priming it for visitors, but not sure how this would help us here on earth :|

ok, im some peace loving alien race, minding my own business, we are so technically advance that all our crisis have been sorted millennia ago, we autonomously harvist crops and the machines supply us with an almost limitless supply of BBQ food and cold beer....

Outstretched on the hover-recliner, enjoying the warming glow of the 3 suns cold one in one hand and a life without worries in the other, then...

some pesky startup planet down the road insists on continually reflecting the sun in our eyes... day in, day out... we cant sleep without some overly basic prime number being burned into our brains... the beer gets warm and the offspring cry...

we maybe peaceful, but just how much warm beer and how many sleepless nights before the invasion begins???

Isn't much of the destruction upon asteroid impact due to the atmospheric shockwave pulling things apart (an raining fire)? Well, no probs on the moon then.

Obviously we can miss the bauxite and the electricity to fabricate a moon-sized tinfoil sail, effectively; how fabricating this device (and sending it spaceward) helps with global warming is immediately clear.

that just happens to be the exact same spectrum as the suns 386 yottawatts.

That's only about 10 orders of magnitude difference guys, I'm sure that'll be really fucking noticeable.

what about if we put go faster stripes on them?

There was a plan in the early 19th Century to do similar things to attract the attention of any Martians who might be watching. Huge heliographs, trenches laid out in geometrical formations and filled with burning oil, planting the desert in patterns.

Mr. Wells' book probably didn't help sell those schemes.

Maybe we can but bigger is always better, and why settle when you can go to the extreme just by upping the tax rates paid by pleebs.

Perhaps the most extravagantly expensive disco ball in existence.

Can't help but think we'll end up attracting a load of Jon Travolta aliens... oh dear, Battlefield Earth might actually come true!

Sounds like "Contact" in reverse. Will our alien would-be friends be patiently awaiting blueprints for a wormhole-traversing spaceship? They'll be sorely disappointed with the best we have to offer......

Anyone remember the 1960s TV series Thunderbirds?

I distinctly remember a story when a solar reflector was used to track the sun and refocus the rays onto a solar generator - to generate electricity for the town.

All went well until the reflector got stuck/broke and bas about to burn the town down with concentrated sunlight in the wrong place - until the Thunderbirds (including Lady Penelope) saved the day.

Knowing how crap the American's are with their engineering, this could well happen in real life with no Thunderbirds to protect us. (Thunderbirds were British - with American accents to make them marketable to the yanks.)

Obviously, we refine the aluminium from native lunar feedstock. The electricity is generated by turning the mirrors upside down to show their photovoltaic sides to the sun, so we can refine the aluminium to make the... oh, wait...

As no living organism originating outside our own little ecosystem has yet been discovered, "astrobiologist" seems a little presumptuous.

Their tenuous grasp of astronomy also suggests the job title is a little misplaced. Just because the moon keeps the same face to earth, doesn't mean it keeps the same face to the sun - are they planning on mounting this mirror on wheels to avoid the lunar sunset?

The only aliens that would get to see the mirror fully illuminated would have to be passing through our solar system anyway. And we already have AmanfromMars!

0/10 Must try harder...

Why not just put it into a badass orbit, free of all the crap that floats along the regular plane? Then you don't need to land on anything that can kill you. Less stupid gravity to get in your way.

Just send the Australian green laser-pointing crims to the moon.

http://www.theregister.co.uk/2008/04/21/australian_laser_pointer_crackdown/

Their ninja pointing skillz and powerful green lasers will quickly blind oncoming alien pilots, thus ensuring they plummet to a fiery death on the moon's surface.

As a bonus, the skies above Sydney will be safe once more for us human travellers.

...preface his exposition with the words "I have a cunning plan"?

All for it! Let's attract some advanced species we know nothing about when we do not even have any idea about how to defend this rapidly degenerating dump against idle rocks coming in from space. JUST DO IT!

Because it's not like the moon ever gets hit by anything. I mean, if it did, the surface would be covered in big cra... Oh. Never mind.

... when they have to show "output" to sanction themselves a few billion worth of expenditure..

1) Any alien observer will see the change in the sun's brightness - rather than the signal itself. (This is how we detect extrasolar planets at present.)

2) This would be a /helluva/ lot more powerful (i.e. "brighter") than the delicate Radio signals we're currently broadcasting. Plus an optical signal wouldn't be turned to mush by dispersion or swamped by the vast amounts of RF the sun naturally "broadcasts".

3) The lizard army is already on route, so what's the point?

4) It was in New Scientist.

The natives of the third planet have mounted a laser weapon on their moon."

"Right. Change course to intercept that dwarf star we passed two light years away. We'll divert it."

The aliens would find out that we have:

- President Bush

- Microcrap software -sort of- running

- Grow food and turn it into fuel for oversized cars, whilst many die of hunger

- Microcrap software -sort of- running

- A lot of problems because of the CO2 emmisions produced by some project to get 27*10^9 tons Aluminium from bauxiet and send it to the moon

- Microcrap....

- No more inhabitants

Not to my liking. Let's use our resources for more usefull things (keeping beer cold and having enough BBQ food like Matt said aliens would do as well).

We feature in their most popular reality-comedy TV show.

This moon mirror is just an externally injected meme to advertise some inter-galatic extra-wrinkle cream.

Let's see... It costs millions of dollars to put one small satellite in orbit. How much, then, will it cost for the countless shuttle/other_vehicle trips to deliver the materials required for this project? On top of that, how much would it cost to produce those materials? And then how much would it cost to install those materials once delivered to the moon? And finally, how would "we" protect those fragile mirrors? Or do these guys think that nothing ever collides with the moon? Hell, forget collisions, what about simple dust/contaminant buildup on the mirrors?

I've heard a lot of stupid ideas from people who desperately try to justify their pathetic job titles (and hence, their pathetic and utterly useless lives), but this one definitely ranks up towards the top.

On the upside, golverd, they will discover we have:

- Paris Hilton

- Big Brother

- Those little things on the end of shoe laces.

Oh crap, we are doomed.

All we need is DNA samples from the Roswell Aliens, fertilise a human egg, find a willing host to bring it to term and.... oh... sounds similar to the film Species...

We're mirrors on the moon,

We shine like a spitoon,

But there's no ET,

So our time is free,

To sing our shining tune...

... at their local.

Also, cue a load of "I call it a Death Star" jokes when they point all the mirrors at troublesome spots on the Earth, "That's No Moon.... It's a Space Mirror" comments, and so on and so forth.

This sounds like a blood huge amount of work for no real payoff- but a big risk of being invaded by aliens or swarmed by nerds.

Hey, you think if you had a telescope you could look up and see yourself looking back at you?

I don't need a coat. I've got The Mirrorball Suit.

You know if you stick your head above the parapet some fucker will put an arrow 'tween your eyes.

Are called Aglets.

Alright, I'm going.

I own 2 acres of the moon. They won't be building on my land!!

The practical way of doing it would be to design a self replicating rover with buglike "wings" shiny on one side and photovoltaic on the other. land some on the Moon around natural resources needed to build more, sit back and wait.

"The natives of the third planet have mounted a laser weapon on their moon."

Thats no moon...

When was the last time a CPU came out of the UK?

Memory?

Video Card?

High tech aircraft? - harrier is the last one I can remember - what, 30 years ago?

Automobiles? - I said the UK

Naval ships? - ya, the UK ones did so well in the Falklands....

But our stuff is all junk....

And damn, some of these comments are funnier than hell!

Get a grip. Telling ET we live on the moon will make them fear us and keep them away.

Once they realise that evolution is a practicable mechanism and that sentient beings can accidentally occur and that they can live on a desert without an atmosphere that has absolutely no heat moderation, their lives will be over.

There's only one warship in commission in the whole world that has shot down an enemy aircraft in combat. That's the venerable HMS Exeter, during Operation Corporate, as it was called then since at the time we definitely did NOT want to call it a war for the Falklands.

Note that this achievement is not related to shooting down friendly and/or civilian aircraft, whether in combat or otherwise. Yes, you know who you are.

Have you read an ancient SF book called "To serve Man" ?? Much better than Footfall, et al (and I'm a Niven and Pournelle fan) !!

Anyway this will not happen because the US govt will put this to tender and accept the lowest bid from a crony ??). The costs start escalating (I was going to say sky rocketing but that would be a bad pun) and the US govt goes bankrupt !! Then some Indian metal refinery (no names mentioned to....) will buy that as scrap, melt down the lot and sell that to the Chinese who uses that to make gadgets to be resold back to the Septics at a vastly inflated profit !! A win-win situation for (almost) everyone !!