Chandrayan-1 moon mission

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harbans
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Re: Chandrayan-1 moon mission

Post by harbans »

even on moon ? without any atmosphere to burn it down and a much lower gravitational pull ?

IIRC it's the power of impact that causes vaporization of most of the meteor. Temperatures rise so much that the whole meteor evaporates. So very large meteor structures are not possible.
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Re: Chandrayan-1 moon mission

Post by ss_roy »

Rahul M,

The 'shard' (first seen by lunar orbiter 3) is over a mile high.. and one of the tower photographed by zond 3 on the far side of the moon is estimated to be close to ten miles high. Neither is surrounded by a crater. Just too weird..
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Re: Chandrayan-1 moon mission

Post by manoba »

Rahul M wrote:even on moon ? without any atmosphere to burn it down and a much lower gravitational pull ?
even on earth many meteorites survive as small pieces after impact, where the structure is already weakened and eroded by the atmosphere and the impact velocity is that much higher.
Hope, the moon is not a "Green Cheese" to 'embed' miles long meteorites in it and ends up something like a blowfish in due course of time.
IMHO, meteorites don't collide with objects in a 90° straight trajectory, instead they take shallow angle of trajectories, especially with huge bodies like moon, which are many times bigger than meteorites.

And FYI, in space, objects move some good hundred km/second. Not inch by inch. Any encounter of two bodies ends up in a huge collision.
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Re: Chandrayan-1 moon mission

Post by Rahul M »

ss_roy, just a random idea. :)

harbans, that's what I'm saying.
'g' (or whatever its lunar equivalent is called) will be much lesser on moon --> much lower impact speed --> much lower kinetic energy --> much less energy to convert into heat.

a rough back of the envelope calculation tells me a body falling on earth will have around 21 times more potential energy to convert into KE and heat than an equivalent mass falling on the lunar surface.
IMHO, meteorites don't collide with objects in a 90° straight trajectory, instead they take shallow angle of trajectories, especially with huge bodies like moon, which are many times bigger than meteorites.
not sure why the impact will be in a shallow trajectory just because the moon is a larger body.
care to explain ?
And FYI, in space, objects move some good hundred km/second. Not inch by inch. Any encounter of two bodies ends up in a huge collision.
hello there, no need to take that condescending tone. I'm aware of what the velocities are like.
btw, any encounter between two bodies is always called a collision, huge or not. :wink:
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Re: Chandrayan-1 moon mission

Post by harbans »

Rahul ji, velocity of impact you're referring to comes into being if you drop an object of mass m from a hieght h both on moon and Earth. Indeed the one on the moon will impact at lower speed. But the influence of g on a meteorite collision on the moon surface has little value when the object itself is moving at many tens of kms per second. Almost every bit of the meteorite would be vaporized.

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Re: Chandrayan-1 moon mission

Post by Rahul M »

harbans ji, you are wrong to think that it is not the gravitational force that creates that tens of km/s impact. why do you think the re-entry parts of missiles enter earth with such tremendous velocity ? or why the space shuttle has to do so much coasting maneuvers before it can slow down enough to land ?
fact is most meteorites when they are 'captured' by a celestial object have very little initial velocity (relative to the celestial body) of their own to begin with.
in most cases the situation is (very roughly) more or less equivalent to bringing in an object from infinity, which is what I calculated. would be glad to be corrected of course.

incidentally, I found a pic of quite a large meteorite though not as large as the moon examples.
http://upload.wikimedia.org/wikipedia/c ... e_AMNH.jpg
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Re: Chandrayan-1 moon mission

Post by harbans »

fact is most meteorites when they are 'captured' by a celestial object have very little initial velocity (relative to the celestial body) of their own to begin with.

Rahul ji, i do not disagree that g does not play a part. It does. But when an object is on a collision course say with the moon or earth orbit at 80,000 km/hr would that really matter if g was a 6th of earths? Plus many of these asteroids and meteorites are ejecta from some deep space explosions so they do have massive velocities to start with. Fact is all objects in the universe already have velocities from the day of the big bang i presume..Fact is there may be several asteroids or metorites with sufficient velocities not to be pulled in by the Earth or Moons gravitational pull and pass by harmlessly.
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Re: Chandrayan-1 moon mission

Post by sumishi »

ss_roy wrote:...
The 'shard' (first seen by lunar orbiter 3) is over a mile high.. and one of the tower photographed by zond 3 on the far side of the moon is estimated to be close to ten miles high. Neither is surrounded by a crater. Just too weird..
Okay here's a nobel prize winner theory for those shardy things :wink:

Part 1: A meteorite hits the moon's surface at night, and out from a nearby huge hole leading to an ice/water reservoir below (like the type LCROSS is hoping to find), erupts a column of melted ice high into the skies, and .... freezes.. :roll:

Someone please fill in the part 2 of the theory -- how the heck is it still staying there, unmelted?? :P

i am outta here... :rotfl:
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Re: Chandrayan-1 moon mission

Post by sumishi »

ss_roy wrote:...

The original 'shard' picture can be seen at:

http://www.lpi.usra.edu/resources/lunar ... 84_med.jpg

It does cast a shadow in the right direction.
On a more serious note, ss_roy, I did manage to locate the "shard" in that image (with much difficulty) at the bottom of the picture against the moon's horizon
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Re: Chandrayan-1 moon mission

Post by Rahul M »

harbans ji, nitpicking : meteorites are supposedly from early days of solar system, not big bang. :)

it's true that many or most meteorites have high velocity to begin with but not all do. all it would take is one large, relatively slow meteorite from the asteroid belt for example to be captured by the moon. as the image I posted earlier shows some meteorites can survive such collisions. this scenario is not inconceivable right ?

then again, as ssroy points out, this theory doesn't explain the lack of a crater. :-?

anyway, we are moving far off from the topic. :wink:
regards.

p.s. sumishi, wonderful idea, you deserve at least half a nobel ! :D
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Re: Chandrayan-1 moon mission

Post by sumishi »

Rahul M wrote:..
Thanks bro! :)
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Re: Chandrayan-1 moon mission

Post by harbans »

Rahul ji, i got your point. But it's not necessary the object striking is from the asteroid belt or our solar system origin remnants. The incoming velocity would depend on where it came from (the asteroid belt, farther out, outside the solar system...) and what other massive objects it passed near on its way here ( passing by a massive object may either speed it up, make no difference, or slow it down, depending on the relative motions of the two). Lots of variables really.

The escape velocity from Earth is about 25,000 mph. That is the outward velocity an object must have if it is to leave the vicinity of the Earth's gravitational field. It is also the velocity acquired by an object originally at rest at a large distance from Earth, during its fall to Earth. Since most asteroids already had a significant velocity before they began falling to Earth, most of them will be traveling significantly more that 25,000 mph at the time they enter the Earth's atmosphere.

Anyways here's a good link for those interested on impact particulars if one strikes on Earth..i played around for some time here: :)

http://www.lpl.arizona.edu/impacteffect ... s_select=0
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Re: Chandrayan-1 moon mission

Post by Amber G. »

FWIW - on the "impact" of a meteorite on moon (or any other object for that matter)

One will not go wrong, if one just uses (forget "g" etc) the relative velocity of object (before it hits moon) and just uses (1/2mv^2) as total energy which will end up heating it up (and any dust cloud etc it raises)

Velocity of moon (wrt to say sun) is pretty much known (about 30Km/sec)
Velocity of the object (again from first principle ) - you can get pretty good value if you know where it came from ( Total energy is prop to "a" (or semi major axis) and all you have to do is to subtract PE due to gravitational potential due to sun (prop to distance from the Sun)

Relative direction you have to calculate (it depends on particular object)
(You may have to add - gravitational effect due to moon - but it really does not matter if you know the "v" before the impact)

Bottom line: depending upon the object and its velocity it may vaporise or it may not.

Many objects (eg comets) are just nothing but a dirty snow-ball (almost made of ice... and some are nothing but pure iron ... so mass may vary quite a bit too.
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Re: Chandrayan-1 moon mission

Post by Amber G. »

harbans wrote: The escape velocity from Earth is about 25,000 mph. That is the outward velocity an object must have if it is to leave the vicinity of the Earth's gravitational field. It is also the velocity acquired by an object originally at rest at a large distance from Earth, during its fall to Earth. Since most asteroids already had a significant velocity before they began falling to Earth, most of them will be traveling significantly more that 25,000 mph at the time they enter the Earth's atmosphere.
Just to add: If "large distance from earth" means really "large" then the escape velocity is about 4 times mentioned above..(about 42 Km/sec) (to as not only the thingie escapes earth but sun too..).. and if one consider VERY large (eg out side our galaxy) then it is of the order of 1000 Km/sec or 100 times the value posted...

The key point, of course, as Harbans put it, it is important to know where the object came from, to estimate relative velocity. (For example, if an object is coming from outside or 'edge' of our solar system. the relative velocity, in worse case, may be as much as 70Km/sec).. of course on earth most of the objects reach terminal velocity before they hit earth... and if objects are small enough (eg size of a bacteria ) they may even arrive quite a bit intact. (Bacteria's, if they come from space will survive :))
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Re: Chandrayan-1 moon mission

Post by Sanjay M »

Show me even one site from a credible organization which mentions this "Moon Shard"

Is there a site from NASA? Encyclopedia Britannica? Something?

No, I don't think so.
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Re: Chandrayan-1 moon mission

Post by sumishi »

Sanjay M wrote:... from a credible organization ...
As an aside on "credible" organizations, my take is that no organization is credible. Any organization is basically a conglomerate of humans who have innate propensity to play devious politics and drive events through biases, ego clashes and one-upmanships.

The accepted geo-centric model of the universe held sway for so long till Copernicus, and later Kepler and Galileo, came along to upset the apple cart. Galileo's trial for the helio-centric heresey (he was threatened with torture and imprisonment) is a blot on the history of the credible church.

Einstein could come up with his relativity theories with such elegance because his mind was not indoctrinated by the tunnel visions imparted by normal school education. His theories showed up the limited applicability of Newton's laws. The infallible Newtonians took a fall.

But then, Einstien too, as he bacame older and more set in his ways, could not come to grips with Quantum Mechanics. "God does not play dice!" This was a result of his belief in ordered reality. The greatest scientist in recent history falters!

So who/what is credible today, need not be tomorrow. BBC's news are so negatively slanted against India. Credible?

My two pennies worth... :)
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Re: Chandrayan-1 moon mission

Post by ss_roy »

Sanjay M,

If it is present in a space probe photo (follow my previous links) and casts shadows (with correct orientation) on the moon- it exists!

Is it an alien artifact or a natural formation, Who knows? But we should try to have a closer look.
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Re: Chandrayan-1 moon mission

Post by Sanjay M »

Okay, no more on this, it makes me laugh too much.

Here's a nice article on G Madhavan Nair:

http://timesofindia.indiatimes.com/news ... 083917.cms
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Re: Chandrayan-1 moon mission

Post by yogi »

A hilarious take on the water discovery on The Daily Show. Aasif Mandvi is awesome.

http://www.thedailyshow.com/watch/tue-s ... space-naan
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Re: Chandrayan-1 moon mission

Post by Sanjay M »

Here's another humourous moon musing on Chandrayaan:

http://www.mid-day.com/opinion/2009/oct ... pinion.htm
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Re: Chandrayan-1 moon mission

Post by Sanjay M »

ISRO to Replicate Lunar Surface for Testing
The mock-up of the lunar surface is being set up at Isro's satellite centre, making use of the high resolution pictures clicked by the terrain mapping camera (TMC), one of the payloads on Chandrayaan-1. The model will be replete with moon dust, rocks and craters so that the Chandrayaan-2 rovers can be perfectly tested, according to TK Alex, the director of Isro's satellite centre. The model, estimated to be completed by next October, will cost Rs10 crore to Rs15 crore.
Uhh, wow - what happened to emphasis on low cost?

Look, I want Chandrayaan-2 to succeed, but I don't see how producing a large sandbox with fine-grained dust should cost Rs 15 crore!

What are they going to do - build it aboard a "vomet comet" airplane to simulate 1/6 Earth G?

Somehow I don't think the mission is going to fail if you drop Rs 10 crore off the price of the sandbox.
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Re: Chandrayan-1 moon mission

Post by Gagan »

Maybe there is something else there in the sandbox.

Perhaps the ability to simulate the temperature extremes on the lunar surface? ISRO is once bitten twice shy with the temperature aspects for sure this time around. Makes sense that they'll want to expose lunar rovers and later Antarikshyatris to a more realistic environment.
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Re: Chandrayan-1 moon mission

Post by manoba »

Sanjay M wrote:ISRO to Replicate Lunar Surface for Testing
The mock-up of the lunar surface is being set up at Isro's satellite centre, making use of the high resolution pictures clicked by the terrain mapping camera (TMC), one of the payloads on Chandrayaan-1. The model will be replete with moon dust, rocks and craters so that the Chandrayaan-2 rovers can be perfectly tested, according to TK Alex, the director of Isro's satellite centre. The model, estimated to be completed by next October, will cost Rs10 crore to Rs15 crore.
Uhh, wow - what happened to emphasis on low cost?
Exactly... Why don't they just test their rovers on Indian roads. They precisely simulate lunar, martian and what-not surfaces.

They will have fine dust, pebbles, stones, potholes, rocks, boulders, puddles and slush (now they have discovered water on moon), idhyadi. And the temperature varies from burning to baking to scorching.

And oh, there is an old saying that anyone who managed to learn ride/drive on Indian roads can drive anywhere in the universe.

And of course, GOI spends crores and crores to build these roads.
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Re: Chandrayan-1 moon mission

Post by Shalav »

^^^^

And this pretentious observation adds what to the thread?

re: Lunar environment simulator - 15 crores does seem a little much, however I am pretty sure if they want to simulate lunar environment, they very well can't do it with Earth atmosphere. That certainly means a vacumn chamber. Additionally the extreme temperatures found on the lunar surface would also need to be simulated.

So if they are doing a fair sized vacuum chamber with temperature controls and enough room to enable movement of the lander the price seems ok AFAIAC~ $3 m.
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Re: Chandrayan-1 moon mission

Post by SRay »

The mini-rover will be one of two indigenous rovers, but the second will remain at the satellite centre as a working scale replica of the first. "The second rover will operate on the lunar surface model to match the movements of the rover on the moon in near real time," the scientist said.
This is not clear -- are they going to replicate a large swath of the moon here on earth and run the two rovers simultaneously? Thats what it reads like. I'm more inclined to think that they will use the terrestrial rover to game play navigation strategies for specific obstacles before having the moon rover do the same.
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Re: Chandrayan-1 moon mission

Post by ss_roy »

You have to simulate high vacuum, ionizing radiation (all types), the right kind of dust (composition, size) and temperature extremes beyond those that occur on earth.

The rover has to survive all of this abuse and still keep on working. Plus the facility is used to test workarounds for problems if anything goes wrong on the moon.
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Re: Chandrayan-1 moon mission

Post by Sanjay M »

I think that operating a deep-sea robot submersible would be more difficult than operating a wheeled vehicle in a vacuum. At least there's no crushing pressure, or any water currents.
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Re: Chandrayan-1 moon mission

Post by Kannan »

yogi wrote:A hilarious take on the water discovery on The Daily Show. Aasif Mandvi is awesome.

http://www.thedailyshow.com/watch/tue-s ... space-naan
Haha, thank you. Best clip I've seen in a while!
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Re: Chandrayan-1 moon mission

Post by Kailash »

Gagan
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Re: Chandrayan-1 moon mission

Post by Gagan »

Image
TMC.

So ISRO uses CAD CAM to design everything. Amazing and Jai Ho!
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Re: Chandrayan-1 moon mission

Post by svinayak »

Image

NASA rocket on crash course with moon
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Re: Chandrayan-1 moon mission

Post by Bade »

The MIP landing on the moon was “both symbolic and significant”, Ashok Kumar said. It was significant because both the M3 and ChACE had revealed the presence of water on the moon. India, in its very first attempt, could put a spacecraft in the lunar orbit; it could land a payload on the moon’s surface; and the mass spectrometer was able to detect water vapour in the moon’s atmosphere. “All these are unique successes of the Chandrayaan-1 mission,” Ashok Kumar said. The 3,000 pictures of the lunar surface taken by the MIP’s video camera would help ISRO determine where the lander-cum-rover of Chandrayaan-2 mission should soft-land on the moon, he added.
For all the naysayers so far. MIP worked and saw trace of water well above the surface layer on the moon.
Sridharan dispelled misconceptions that the mass spectrometer detected water on the surface of the moon. It found water vapour in the moon’s thin atmosphere, he said. The purpose of the mass spectrometer was to analyse the gaseous constituents of the moon’s tenuous atmosphere. It was capable of analysing “how much [of gas] was present and what it is composed of,” he said. It did this in latitude and altitude after the MIP split away from Chandrayaan-1 and raced towards the moon’s surface. “The mass spectrometer was sensitive enough to analyse the presence of H2O in the form of gas – in the form of water vapour. It provided this data on November 14, [2008],” the SPL Director said.
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Re: Chandrayan-1 moon mission

Post by harbans »

For those interested in watching LCROSS bomb the moon check these sites giving live coverage:

http://www.mmto.org/lcross/

http://www.nasa.gov/help/multimedia/odplayer.html
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Re: Chandrayan-1 moon mission

Post by Amber G. »

Oh well .. no spectacular videos...
But here is a story about the crash:
U.S. Spacecraft Crash on Moon in Search of Water
Two U.S. spacecraft were crashed into a lunar crater on Friday but scientists said it was too early to say whether the mission to search for supplies of water on the Moon had been a success.

NASA, which is hoping to find sufficient quantities of water to use as fuel for space exploration, said it could take two months to make a conclusive assessment of what was found.

A two-ton empty rocket stage slammed into the eternally dark Cabeus crater near the moon's south pole at 4:31 a.m. PDT (7:31 a.m. EDT), intended to throw up a plume of spray from any ice that was there.

Instruments on a second craft, that flew through the plume and hit close to the same spot four minutes later, as well as a lunar orbiter and telescopes on Earth captured data that could show whether there was ice there.

Video transmitted back from the trailing craft did not show, as hoped, the eruption of debris, but infrared devices showed a hot flash that indicated a crater about 18 to 20 yards (meters) wide.
<snip>
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Re: Chandrayan-1 moon mission

Post by Kailash »

Jayant Narlikar Urges For Checking The Presence Of Life On Moon

Well this is as inconceivable as "water on the moon" was some time ago..
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Re: Chandrayan-1 moon mission

Post by sanjaykumar »

But of course, goes without saying. India needs soil samples from the poles. The Chandrayaan 2 mission needs to be proiritised, this is an extremely important goal.


He mentioned that the balloon testes, which were conducted in 2001 and 2005, have proved the presence of micro-organisms at a height of 41 km from earth’s surface.

Don't these writers proof read their stuff, I don't unless it is for publication.
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Re: Chandrayan-1 moon mission

Post by Prasanth »

Guys,

Found two clips from space forums on Chang E 1 3D mapping. Maybe can shed some light on their effort.
http://video.sina.com.cn/news/c/v/2009- ... 5507.shtml

http://space.tv.cctv.com/video/VIDE1210773634173393

The moon does look pretty amazing in 3D.
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Re: Chandrayan-1 moon mission

Post by juvva »

Another Chandrayaan instrument -SARA, gives insight into lunar water formation, new imaging techniques and inputs into an upcoming mission to Mercury...this is turning out to be a windfall mission !!! :

http://www.moondaily.com/reports/How_Th ... r_999.html
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Re: Chandrayan-1 moon mission

Post by sumishi »

Prasanth wrote:Guys,

Found two clips from space forums on Chang E 1 3D mapping. Maybe can shed some light on their effort.
http://video.sina.com.cn/news/c/v/2009- ... 5507.shtml

http://space.tv.cctv.com/video/VIDE1210773634173393

The moon does look pretty amazing in 3D.
Does the second link show Moon's terrain? Its probably the Himalayas.
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Re: Chandrayan-1 moon mission

Post by disha »

Prasanth wrote:Guys,

Found two clips from space forums on Chang E 1 3D mapping. Maybe can shed some light on their effort.
http://video.sina.com.cn/news/c/v/2009- ... 5507.shtml

http://space.tv.cctv.com/video/VIDE1210773634173393

The moon does look pretty amazing in 3D.
Yep with now water found, all the greenery and the snow capped mountains and valleys carved by water. Wow, never realized Moon is so green! :rotfl:

The second clip is of some mountain range. The first one has few clips of moon in 3D but nothing ground burning.
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