Decades-Old Soviet Reflector Spotted On the Moon

cremeglace writes "No one had seen a laser reflector that Soviet scientists had left on the moon almost 40 years ago, despite years of searching. Turns out searchers had been looking kilometers in the wrong direction. On 22 April, a team of physicists finally saw an incredibly faint flash from the reflector, which was ferried across the lunar surface by the Lunokhod 1 rover. The find comes thanks to NASA's Lunar Reconnaissance Orbiter, which last month imaged a large area where the rover was reported to have been left. Then the researchers, led by Tom Murphy of the University of California, San Diego, could search one football-field-size area at a time until they got a reflection."

Comments

Turns out...

[Kell Bengal]

... it was on the moon the whole time.

Re:Turns out...

[Cryacin]

What, the film studio? :P

Re:Turns out...

[azjeff]

You forgot "Technicians make them work".

Re:Turns out...

[jtownatpunk.net]

It's always in the last place you look.

Re:Turns out...

[gyrogeerloose]

It's always in the last place you look.

Yeah. Now I wonder if they could help me find my keys.

Re:Turns out...

[MrKaos]

... it was on the moon the whole time.

Kinda ironic that Murphy found it in the wrong place.

Re:Why is this a surprise?

[Scarletdown]

In Soviet Russia...

Nah, too obvious.

Re:Why is this a surprise?

[MoonBuggy]

Well if they'd been looking kilometres in the wrong direction, it implies that there wasn't a precise record of its position!

Re:Why is this a surprise?

[Anonymous Coward]

It all seems so easy! And yet it's not. Finding a tiny object like that isn't easy at all. The Moon is a big place, really.

As for dust storms and delinquents... somehow the return from from the Lunokhod 2 reflector has degraded significantly over time. Who knows why? It may have tipped, or perhaps was hit my a small meteor. Nobody knows.

This find is nice because of the position. It allows for more precise measurements than were previously possible. It's pure win.

footbal-field sized

[doti]

is this an imperial unit or what?

Re:footbal-field sized

[Nidi62]

Well, metric would have been pitch, wouldn't it?

Re:footbal-field sized

[jandoedel]

only if the emperor plays on it.

why do you ask?

Re:footbal-field sized

[SEWilco]

It doesn't specify in the article, so I don't know if they're using Metric or Imperial football fields.

That should be "Metric or New Republic football fields."

Re:footbal-field sized

[roman_mir]

African or European unit?

Re:footbal-field sized

[Beardo the Bearded]

Canadian football fields are 110 meters.

At least, as far as I know. I don't think I've actually seen one.

Re:footbal-field sized

[Monkeedude1212]

This is correct. Not including Endzones of course, but yes, there is a 50 yard line on both sides, and 5 yards from both of them is the "C" center line.

Re:footbal-field sized

[rickb928]

American Football is played on a field 360 by 160 feet, or 109.72m by 48.77m, or 5351.04sq.m. Some of the length is end zones.

IFBA declared a fixed size for a pitch of 105m long and 68m wide, which is 7140 sq.m, instead of instead of a minimum and maximum length - from 100m to 110m - and a minimum and a maximum width - from 64m to 75m. So the olde standard allowed fields from 6400 to 8250 sq.m.

So an American Football field would be from 750 millisoccerfields to 650 millisoccerfields.

Or a pitch would be from 1540 millisoccerfields to 1200 millisoccerfields.

American Football is always played on a narrower, but sometimes longer, field. However, we rarely think of the end zones as playable area, so think of a football field here as 100 yards long. And if you're playing soccer on an American Football field, it *is* about 100 yards long, as the goalposts rarely are moved, and you usually end up giving up most of the end zones. This and the narrow fields many U.S. high schools have available really stunts play, as width is so important in soccer. I would take a 90m field that was 60m wide over a 100m field that was 48m wide.

It immediately caught me that someone somewhere thought an American Football field was larger than a soccer pitch. this is just not so.

Now, hockey was even more interesting to me, where rink size varied greatly. The Montreal Forum had a huge sheet, and they preferred skaters such as Guy LeFler, who could drive you crazy trying to find them, much less check them. The old Boston garden had a small sheet, with tight radius corners. Going into the Bruins' corners with any of the old-style Bruins defensemen coming in pretty much guaranteed you were going to be squashed like a bug. Some old Bruins used to talk of Bobby Orr's stickhandling as playing ping-pong in a phone booth. In the Forum, this was still important, but trying to crash the boards in the Forum often got you nothing but boards.

In sports, for sure, size does matter.

Re:footbal-field sized

[AmigaHeretic]

>>is this an imperial unit or what?

You mean soccer?

Re:footbal-field sized

[vegiVamp]

Well, if it's a metric football field, americans would probably call it a soccer field.

Re:Why is this a surprise?

[roman_mir]

My god, your logic is impeccable!

I believe that this story is very informative and that we all will get very insightful comments from everyone involved, and some of the posts will be funny, while others may be somewhat redundant, however there always will be a few underrated and overrated commentators, but it is all good as long as it does not lead to any flamebait here. Of-course Trolls are welcome to join the conversation, just as per usual arrangement.

Oh, and the Anonymous Cowards... I see you, I see you and your reflections in the Moon.

Re:Why is this a surprise?

[jandoedel]

or maybe they had a very precise, but inaccurate record of the position.

now we are six

[at10u8]

This means there are now six useable reflectors. See the list from the investigators.

Re:now we are six

[Spatial]

Those laser ranging retroreflectors were put on the Moon by aliens.

It's obvious really. If they weren't then my conspiracy theories about the Moon landings would be proven false. And that's physically impossible, because they're true!

Re:now we are six

[sznupi]

The list to which you linked to includes Lunokhod 2. There are five, now all usable.

Re:now we are six

[sznupi]

...I mean, "includes two Lunokhods"

Re:now we are six

[blair1q]

Sure. Moon aliens. From the Earth.

Re:why bother ?

[ProdigyPuNk]

There are other mirrors up there. why actually search for this one ?

FTFA: Now the team can eventually pin down the changing shape of the lunar orbit to the millimeter to help test Einstein’s theory of general relativity.

There might be other reflective things on the moon, but I assume that this one is somehow special. I at least *hope* that the people searching for it know what they are doing :p

US left a corner reflector as well

[Anonymous Coward]

American astronauts left a corner reflector as well for earth to moon distance measurements.

This I always felt was the best proof that humans were on the moon, as opposed to say that the whole thing was faked in a movie studio.

Neil and Buzz left it there
http://science.nasa.gov/science-news/science-at-nasa/2004/21jul_llr/

Re:US left a corner reflector as well

[EvanED]

This I always felt was the best proof that humans were on the moon, as opposed to say that the whole thing was faked in a movie studio.

Eh, personally, I think that's not a very good argument. This soviet thing is as much a counterargument as anything -- the Soviets have one on the moon, but they didn't send anyone. Probes can place reflectors.

The best argument for the moon landing IMO is the scrutiny the Soviets would have had to put into it. They would have been able to pick up telemetry and the transmissions from the craft (hell, amateurs were able to see the Apollo ships through telescopes) during the flight.

Long story short: we sent something of the right size to the moon, landed it there, and brought it back, and it was transmitting what we said it was transmitting. You can concoct some half-baked explanation of us sending up a recording or something like that (actually a recording wouldn't work as they transmitted time-sensitive information, so you'd have to say that NASA was transmitting a hidden stream to the craft what they would transmit back), but IMO by the time you get to this point it seems like the hard parts of Apollo were basically done.

Re:US left a corner reflector as well

[Mr. Freeman]

We actually left several. I believe that every landing carried one. I can't be sure about that last point, but I do know there's more than one currently up there.

Re:US left a corner reflector as well

[Beardo the Bearded]

The moon landing was a fake, but it was filmed on the moon. They didn't want you to know that we've had a moon base since 1964.

Re:US left a corner reflector as well

[sznupi]

There are only five apparently, at least among those which we can resolve - three from Apollo and, now, two from Lunokhods.

But the one from first Lunokhod is apparently a bit more valuable and interesting than the rest; placed in the most northerly location, can give more data about "wobble" of the Moon and hence its precise rotation.

Re:US left a corner reflector as well

[Monkeedude1212]

No you dummy, it was a soundstage on mars.

Re:US left a corner reflector as well

[Princeofcups]

The best argument for the moon landing IMO is the scrutiny the Soviets would have had to put into it. They would have been able to pick up telemetry and the transmissions from the craft (hell, amateurs were able to see the Apollo ships through telescopes) during the flight.

Long story short: we sent something of the right size to the moon, landed it there, and brought it back, and it was transmitting what we said it was transmitting. You can concoct some half-baked explanation of us sending up a recording or something like that (actually a recording wouldn't work as they transmitted time-sensitive information, so you'd have to say that NASA was transmitting a hidden stream to the craft what they would transmit back), but IMO by the time you get to this point it seems like the hard parts of Apollo were basically done.

The people who deny the moon landing don't understand even the rudiments of physics or electronics, and they would not be swayed by your "scientific trickery". Nothing short of writing your name in gigantic green letter large enough to read with the naked eye across the face of the moon would satisfy them.

Re:US left a corner reflector as well

[BradleyUffner]

This I always felt was the best proof that humans were on the moon, as opposed to say that the whole thing was faked in a movie studio.

I tried that logic with someone who says it was faked. Their reaction was to say that "Ohh sure, we had rockets that could go to the moon, but they couldn't support human life. The reflectors were dropped there autonomously from lunar orbit".

I gave up trying shortly after that.

Re:US left a corner reflector as well

[RobTerrell]

It's all true:

http://www.vgg.com/tr/tr_102201_moon.html

Re:US left a corner reflector as well

[CohibaVancouver]

The best argument for the moon landing IMO is the scrutiny the Soviets would have had to put into it

For me the best arguement is the fact that it's forty years later and no one has made a deathbed confession that they worked on faking the landing. To fake it you would have needed many many many people to keep a secret for 40 years. Impossible IMO.

Re:US left a corner reflector as well

[Beardo the Bearded]

Don't be ridiculous. The sand would be the wrong colour...

... unless that's what they want us to think!

Re:US left a corner reflector as well

[Beardo the Bearded]

No, that soundstage was used to film Capricorn One

Re:US left a corner reflector as well

[Dishevel]

Thank God they were there too. If not for the film crew that day the nuclear waste dump on the far side of the moon would have gone supercritical and possibly launched the moon and all that was on it deep into space.

Re:US left a corner reflector as well

[baKanale]

The crazy part is that someone actually believes that. (Sorry about the Godwin, btw.)

Re:US left a corner reflector as well

[R3d M3rcury]

I always enjoy this...

Being able to send data to and from the Moon was achieved in the early 1960s. So I postulate this:

NASA transmitted to the Moon. The transmission was also sent to the astronauts working on the faked moon set in "real time." The astronauts' responses were sent to the Moon which echoed them back to Earth based upon who was doing the talking (ie, when the CSM pilot spoke, it came from the CSM, when the moon-based astronauts spoke, it was sent to the LEM).

At least the speech would appear to come from the Moon. Telemetry from instruments aboard the spacecraft would be received by NASA and sent to the appropriate instruments on the Earth-bound fake (or received directly--as you say, anybody could receive them) so that any conversations about what is being seen would be accurate.

The idea would be that you have to fake out NASA as well. In this scenario, you basically have to have somebody "tap" the voice transmissions from NASA to the astronauts and telemetry data received by NASA at the source and resend it to the fake moon set. You wouldn't need high-ranking NASA people, just somebody to install the tap and make sure it kept working.

The best argument for the moon landing, in my opinion, is that we brought back lots of interesting stuff.

Re:US left a corner reflector as well

[konohitowa]

I still don't know why the fact that Soviets haven't said anything doesn't convince them. They were technologically in a position to absolutely and horribly shame the United States if no human beings actually travelled to the moon. But nothing of the sort was ever claimed by them.

That's because we game them Nikola Tesla and the location of Atlantis in exchange for their silence on the matter. I'm not sure what we gave them to keep quiet about 9/11; perhaps the location of Tesla's base on Mars after he escaped from Earth.

Re:US left a corner reflector as well

[EvanED]

The astronauts' responses were sent to the Moon which echoed them back to Earth based upon who was doing the talking (ie, when the CSM pilot spoke, it came from the CSM, when the moon-based astronauts spoke, it was sent to the LEM).

Well, not just to the moon per se, but to the actual (unmanned) Apollo craft they were sending to and from the moon at that time. And that stream would have to be undetectable. Regardless, it'd have had to be really well-done to fool the Soviets.

The idea would be that you have to fake out NASA as well. In this scenario, you basically have to have somebody "tap" the voice transmissions from NASA to the astronauts and telemetry data received by NASA at the source and resend it to the fake moon set. You wouldn't need high-ranking NASA people, just somebody to install the tap and make sure it kept working.

Incidentally, this is what I think is the most plausible way this conspiracy would have been accomplished: by keeping almost everyone in the dark. Satisfies that "deathbed confession" objection someone else had.

The best argument for the moon landing, in my opinion, is that we brought back lots of interesting stuff.

This is also a plenty good argument. (There's not exactly a dearth of good arguments here.) I just find it less compelling personally because I don't have a good answer to "the moon rocks are faked/from an asteroid/whatever".

Re:US left a corner reflector as well

[Thing 1]

A detonation on the far side of the moon would send it careening into us, would it not?

Re:US left a corner reflector as well

[navyjeff]

Merely mentioning Nazis or the Third Reich doesn't automatically Godwin a thread. One has to make a comparison of a particular post or person to the Nazis as a way of insulting them or an ad hominem.
Here's a reference.

Re:US left a corner reflector as well

[Anonymous Coward]

Nazis always say that..

Re:US left a corner reflector as well

[socsoc]

Nothing short of writing your name in gigantic green letter large enough to read with the naked eye across the face of the moon would satisfy them.

What if I was a brewery from Latrobe, PA and grafitti'd the Moon with our branded horse, in green. Would that satisfy them?

Re:US left a corner reflector as well

[mbone]

We left 3 LLR retroreflector arrays, at the Apollo 11, 14 and 15 landing sites. (That is 3 out of 6, so exactly 1/2 of the landings.)

Apollo 15's LLR array is by far the biggest, and so it is used the most often for ranging. But, to get the rotation (librations) of the Moon, you need a distribution in both latitude and longitude. The Apollo LLR arrays form a nice, but not especially large, triangle centered around the center of Near Side, Lunakhod 2 is usefully separated from them to the North-East, but Lunakhod 1 is all the way across Mare Imbrium in the North-West quadrant of the Near Side of the Moon. Ranging from Lunakhod 1 will substantially help the determination of Lunar librations.

Re:US left a corner reflector as well

[gyrogeerloose]

I'm not sure what we gave them to keep quiet about 9/11; perhaps the location of Tesla's base on Mars after he escaped from Earth.

The formula for Coca-Cola and the recipe for McDonald's Secret Sauce.

Re:US left a corner reflector as well

[KDR_11k]

NASA claims that faking the moon rocks to a degree where they would fool the scientists examining them would have been more expensive than the actual moon landing.

Re:US left a corner reflector as well

[someone1234]

Of course it was. But with postprocessing they took out most of the red.

Re:US left a corner reflector as well

[master_p]

The best argument for the moon landing IMO is the scrutiny the Soviets would have had to put into it. They would have been able to pick up telemetry and the transmissions from the craft (hell, amateurs were able to see the Apollo ships through telescopes) during the flight.

There is no proof that the spacecraft contained any astronauts. The transmissions from the spacecraft could very well be transmissions received from Earth. If the astronauts where in a studio, then they could reply to Houston at the very moment Houston spoke, but Houston would receive the answer 3 seconds later because the answer was transmitted to the probe first and then back to Houston.

by the time you get to this point it seems like the hard parts of Apollo were basically done.

The hard part is actually to make humans set foot on the moon, which is hardly proven. You are right that the found Soviet reflector is actually a counterargument - if probes can put things on the moon, then things on the moon are not proof that humanity ever landed there.

Re:US left a corner reflector as well

[CohibaVancouver]

How many people do you think are now keeping the secret of government nine eleven conspiracy?

Zero.

Re:US left a corner reflector as well

[damien_kane]

NASA claims that faking the moon rocks to a degree where they would fool the scientists examining them would have been more expensive than the actual moon landing.

To which I reply it probably would have been.
It was probably cheaper just to buy them off, though.

"Sure, those are real moon rocks, pay no attention to the USD1M increase in my bank balance, or my new tax-exemption status"

Re:US left a corner reflector as well

[Dishevel]

It might have been real close.

Re:US left a corner reflector as well

[wwphx]

The US left three: Apollo 11, 14, and 15, for a total of five potential targets.

Re:US left a corner reflector as well

[Thing 1]

Ah yes, I can see the physics now. Thanks.

Re:Why is this a surprise?

[Anonymous Coward]

Fuck! The Moon!!

Re:Why is this a surprise?

[adonoman]

Oh, and the Anonymous Cowards... I see you, I see you and your reflections in the Moon.

Except that the mirror on the moon is a retroreflector, meaning you only see yourself. You've just outed yourself as Anonymous Coward!

Re:Why is this a surprise?

[LWATCDR]

But it could have been damaged by the environment. The thermal cycling is pretty extreme on the moon.

Re:Why is this a surprise?

[roman_mir]

And yet, I post under my nick here. Oh Your God! I am the ACTUAL Anonymous Coward but I am hiding behind a nick name. Wow, this is just mind shuttering! Am I hiding from myself I wonder?

Re:Why is this a surprise?

[roman_mir]

Hell, and whose fault is it? Whose fault is it, MoonBuggy 611105?

Re:Why is this a surprise?

[Chelloveck]

Well if they'd been looking kilometres in the wrong direction, it implies that there wasn't a precise record of its position!

On the contrary, it was very precise. Inaccurate as hell, but very precise!

They should have just stuck a GPS receiver and a cell phone on it...

Re:why bother ?

[SgtAaron]

There are other mirrors up there. why actually search for this one ?

FTFA: Now the team can eventually pin down the changing shape of the lunar orbit to the millimeter to help test Einstein’s theory of general relativity.

There might be other reflective things on the moon, but I assume that this one is somehow special. I at least *hope* that the people searching for it know what they are doing :p

There are certainly other reflectors out there on the moon, that could and have been used for measuring the moon's distance--and for some time now. I can't imagine what could be special about this one, except for the quality, perhaps? Nah. What if it's not kosher for others to shoot lasers at the reflectors that other scientists use? The article ends there and is skimpy on details.

In Soviet Luna...

[Anonymous Coward]

...reflector dish spots YOU!!!

Re:Who said it was a surprise?

[Chris Burke]

Who said it was surprising? Why does "surprise" have to be involved? When you're searching for something for forty years, even though you know it must be there somewhere, actually finding it is noteworthy.

Headline: Deepest Part of Marianas Trench Discovered.

Locke2005: Why is that a surprise? You can't have a bottomless trench, so of course there has to be a deepest part!

cool.

[mirix]

Every time I see pictures of the soviet rovers, I can't help but think how bizarre the things look. Like a combination of a bathtub and a baby carriage.

wiki article about one of the rovers.

I found it neat that it had some decaying isotope, and a lid, to close and keep the internals warm during lunar night. Too bad they didn't have lithium ion batteries back then eh? Not sure what they used, but 1970's era rechargeable batteries tend to suck period.

The wheels are especially weird looking, like something from a nightmare.
wheel closeup picture

Re:cool.

[egcagrac0]

Cold batteries suck, period.

Cold tends to slow down chemical reactions. Most batteries rely on chemical reactions to move electrons.

As Khan said so eloquently, "It is very cold in space".

Fun experiment: if you have an old tape player that runs on batteries, stick the batteries in a refrigerator for a few hours. Pop them back into the player, listen to the tape speed up as they get warmer.

Re:cool.

[mirix]

I live in central Canada, so I'm quite experienced with cold batteries being useless :-)

Re:cool.

[mirix]

I know you are joking, but apparently a couple derivatives of these rovers helped in the Chernobyl cleanup. Odd coincidence I guess.

link

Re:cool.

[Tablizer]

Every time I see pictures of the soviet rovers, I can't help but think how bizarre the things look. Like a combination of a bathtub and a baby carriage.

In general most Soviet probes tended to be rounder than US counterparts, which are boxy or polygonal. It would be interesting to ask an experienced Russian probe designer why they are rounder.

They also tend to have more pipe-like tubes on the outside. US probes perhaps hide such behind metal foil, which is more common on US probes for some reason.

The Soviet probes almost have a steampunk look to them.
 

Re:cool.

[egcagrac0]

I should have picked up on your intuitive understanding of cold by your use of the word "eh?", eh?

Wisconsin is great for the liquor, but lousy because there's no Tim Horton's (or Waffle Houses). The concessions we make...

/still really cold for a chunk of the year

Re:cool.

[qc_dk]

Not sure what they used, but 1970's era rechargeable batteries tend to suck period.

So they can also be marketed as a feminine hygiene product?

Badabum Tsching. I'll be here all week folks. Remember to tip you waitress.

Re:cool.

[wiredlogic]

One of the characteristics of Soviet spacecraft design is that they seal everything they can in atmospheric pressure vessels. This simplified the thermal design problem because convective cooling could be employed in the pressurized parts. Some of their manned spacecraft designs were repurposed as satellites using this principle. Their purpose built satellites were also pressurized. The "tub" of the lunokhod is a pressure vessel for the electronics. The Wikipedia page even mentions that the electric motors in each wheel were also pressurized although that was possibly more for lubrication and dust protection purposes. In contrast, the typical American design places the electronics in vacuum and they are thermally bonded to a heat spreader that provides for conductive cooling.

Re:cool.

[seandiggity]

I found it neat that it had some decaying isotope

That isotope is the infamous polonium-210.

Re:Why is this a surprise?

[poena.dare]

How old is that defector? Someone should tell him Stalin is dead!

SETI is HARD

[renrutal]

If you take decades to find a reflector in the nearest astral body, it quite puts in perspective the whole difficulty of searching for extraterrestrial life light-years away.

Re:why bother ?

[sznupi]

Lunokhod 2 is in the most northerly position out of all available retroreflectors on the Moon, which will contribute to much more precise data about the Moon "wobble" (since the distance of Lunokhod 2 is greatly affected by it, in comparison to something near the center of the view from Earth)

Re:Why is this a surprise?

[egcagrac0]

In Soviet Russia, Mod points You!

Re:Why is this a surprise?

[Anomalyst]

thermal cycling is pretty extreme on the moon.

Well, of course, with only 1/6 gravity, using an off the shelf standard velodrome construction, the banking on the track would be totally out of whack.

PS.

[sznupi]

I mean, Lunokhod 1 in the above post...the one about which the story is ;/

Re:Sarah Palin is an Astronaut

[blair1q]

Sure. Her house is on the moon.

She can't be from this planet.

Zapped

[pgn674]

They find it, and what do they do first? Zap it with a laser. No wonder it was hiding!

The moon landing was faked...

[RepelHistory]

...at a sound-stage on Mars.

Re:Why is this a surprise?

[geekprime]

/rats

Did you hear?

[CorporateSuit]

I hear that day was pretty crazy around the observatory. Imagine the surprise of the scientist who looked through the telescope at the moon, only to see someone looking through a telescope straight back at him! It was only after he crapped his pants did they figure out they were looking at a mirror!

Re:Why is this a surprise?

[AstrumPreliator]

To expand upon this a bit I can say that Pi = 5.981734819456272. As you can see I am very precise however, I am not at all accurate.

Re:Why is this a surprise?

[segin]

Hey, look, it's SlashTroll2005!

Not weird. Antique.

[nuckfuts]

If you'd ever seen old-fashioned farm equipment, you wouldn't find the look of those wheels very unusual.

Re:Not weird. Antique.

[mirix]

I've seen old tractors before, I was thinking more of the holes in the paddles, and the drum being made from screen.

Re:Ignore the disinfo agents. Here's how it works

[oatworm]

I'm going to ask my boss for a purchase order. The only item on that purchase order will be for a sufficient quantity of whatever this guy's smoking to get the rest of the office to stop asking me why Verizon blew up our office phone service again.

That is all.

How about mars?

[WindBourne]

You know, it would be nice to have a reflector on mars. I wonder if it is possible to go that distance.

Re:How about mars?

[mbone]

You know, it would be nice to have a reflector on mars. I wonder if it is possible to go that distance.

Distance is a problem (ranging sensitivity is proportional to 1/distance to the fourth power), but aberration makes this sort of passive Laser ranging to the planets impossible. (The retroreflector arrays return photons towards the direction they were received from, which is not the direction the Earth will be at one round-trip time later.)

There have been several proposals to do active laser ranging to spacecraft or to landers on the planets. Ranging accuracies in the tens of picoseconds should be available from this, and I regard this as inevitable in the long run as interplanetary communications moves from radio to optical lasers to get higher bandwidth.

Re:How about mars?

[elrous0]

Mars has an atmosophere that would presumably get in the way and dirty up the mirrors over a short time period.

Re:Why is this a surprise?

[PPH]

They were just using the wrong football field units.

Re:Sarah Palin is an Astronaut

[Tablizer]

Is this your round-about way to say that you got mooned by Palin?

oops

[Green Salad]

wobble detector? um...Does that mean we're not supposed to huck moon rocks at it?

Yeah ! Finally !

[mbone]

This is way cool. The LLR (Lunar Last Ranging) people have been looking for this for a long, long time.

This (by providing a new fiducial point on the Moon) will significantly help Lunar geodesy.

Note, by the way, that LLR returns are always exactly 1 photon per shot, so this flash was no fainter than any other LLR return.

Re:Yeah ! Finally !

[mbone]

Oh, by the way, while the Lunakhod's were Soviet, the French actually built the retroreflectors, so this is a Soviet-French experiment.

Re:Yeah ! Finally !

[Fleetie]

Why are LLR returns always exactly 1 photon per shot? I see no reason why that should be true. Also, I read that the American ones used to return 1 photon back per shot sometimes?

Re:Yeah ! Finally !

[mbone]

Because (unlike the case with Satellite Laser Ranging), the expected return per shot is actually less than one photon. So, a shot returns either zero or one photons.

They do lots of shots and gate (time filter) the returns to get a single range estimate, based on maybe 1000 photon returns. But, each shot still returns only one photon at most at a time. (With the appropriate color filter, and a nanosecond size time gate, there is rarely a photon from the solar illumination of the Moon, and those that get through add only a little noise.)

The new Apollo system will have better statistics, and may get above 1 photon per shot, but there are actually pretty good reasons to only take the first photon from a shot, so I suspect that they will continue to only use 1 at a time.

Re:Yeah ! Finally !

[the_other_chewey]

Note, by the way, that LLR returns are always exactly 1 photon per shot, so this flash was no fainter than any other LLR return.

"The large aperture of the telescope in combination with the good atmospheric "seeing" at the site has launched us into the regime of recording multiple returned laser photons per pulse"
(http://www.physics.ucsd.edu/~tmurphy/apollo/apollo.html)

Also, what you mean is what's detected from a return, not what actually returns - which is quite a bit more.

Re:Why is this a surprise?

[dunkelfalke]

Stalin died in 1953, even before the Sputnik launch. Lunokhod launch was in 1970.

Endzone

[Dthief]

Is part of he playable field.

Kickoffs are caught in it. Passes are thrown into it. Field Goals are run back for touchdowns from it. And the defense uses it during a goal line stand.

Re:Endzone

[rickb928]

True. But ask most fans how long the field is, and many if not most will say "100 yards". Then we think "huh. My team's longest return is 108 yards".

Re:why bother ?

[mbone]

What if it's not kosher for others to shoot lasers at the reflectors that other scientists use?

They are mirrors. Everyone who does this (US, French, Germans, Russians, so far) has used all the ones up there.

Re:Why is this a surprise?

[L4t3r4lu5]

Does that mean I can get 2.840142166 more slices?

Re:In Soviet Russia

[Kerckhoffs Principle]

Their space program pretty much sucked.

Well, considering the fact that they : - launched the first satellite in space - shot the first animal in space - had the first man in space - reached the moon first (Luna I & II) I'd have to agree with you that their program obviously sucked!

Didn't even make it in Top 10 Technology Mistakes

[kriston]

Didn't even make it in Top 10 Technology Mistakes:

http://www.pcauthority.com.au/News/173067,top-10-technology-mistakes.aspx

Re:Sarah Palin is an Astronaut

[elrous0]

Plus, as a narcissistic former beauty queen, she already has a great deal of expertise with mirrors.

Re:Ignore the disinfo agents. Here's how it works

[Beardo the Bearded]

Yeah, damn, I'm from BC and this guy's stuff looks epic.

Brilliant post though. I'm honestly not sure if he actually believes that or if he's having a wag.

That's no reflector!

[noidentity]

That's no reflector! Er, wait, I think I messed up the line...

Re:Why is this a surprise?

[wwphx]

It's well demonstrated with Lunokhod 2: that laser reflector doesn't produce returns when it's in direct sunlight, it can only be targeted when it's in shadow.

And I was there!

[wwphx]

At least for the discovery. My wife is Dr. Russet McMillan, and I was spotting for her during that laser run. (Spotters are armed with kill switches and stand on the catwalk and watch for aircraft). She was extremely excited when she found it! Unfortunately on our next run, Sunday night, she couldn't hit it. I think our next laser run is 1am Thursday or Friday, we'll see what happens then.

A better source of information on this is the UCSD press release: http://physicalsciences.ucsd.edu/news/releases/release_detail.php?release_id=296

I love to point out that Russet and the observatory was the final segment of the Mythbusters Lunar Landing episode.

Now I have to design a t-shirt that says "I helped to find the lost Lunokhod 1 lander and I had to make my own stupid t-shirt!" I wonder if Photoshop has a Cyrillic-looking English font.

Re:Why is this a surprise?

[davidbofinger]

Have you been baking hyperbolic pies again?

Lunokhod on TV

[hcdejong]

In the recent discussion about the other Lunokhod, someone mentioned the Discovery documentary Tank on the moon. I've seen it since; if you want to know more about these very impressive vehicles, this is a good starting point.