### Author Topic: Curiosity fake...?  (Read 10959 times)

#### Rob260259

• Earth
• Posts: 102
##### Curiosity fake...?
« on: August 05, 2013, 03:43:47 PM »
From a moon hoax conspiracy theorist:

"A parachute will NOT work in a vacuum or a very thin ,light atmosphere.The lander ,according to my calculations, would have hit the martian surface at over 30,000 miles per hour,instantly desintegrating. For there to be enough accumulated drag from any latent﻿ noble gases around the martian surface -even a thinner atmosphere - I estimate the chute would have had to have been a minimum of 15-18 miles in diameter, to have had any significant effect on the descent rate in these conditions.The air density of Mars is indeed considerably thinner than that of Earth,﻿ however the atmospheric density on Earth varies with altitude. As you rise higher into Earth's atmosphere so the density drops, and it eventually falls off to near zero as you start to escape the Earths Atmosphere.

Mars has an average (depending on the hight) atmospheric density of 0.087 Psi here on earth you got a sea level pressure of 14.7 psi you notice a difference ? You need a certain atmosperhic densitiy to enflate the parachute and to gain a velocity reduction. But that is impossible with that thin atmospere."

Anyone able to refute this with a simple equation, as I am not an expert in this field.

#### Chew

• Jupiter
• Posts: 545
##### Re: Curiosity fake...?
« Reply #1 on: August 05, 2013, 04:29:50 PM »
First, it is a known fact that almost all conspiracy theorists are barely capable of adding, let alone multiplying and working with squares. Ask to see his math. I would bet anything he will balk and try to bluff his way through.

Second, tell him atmospheric density is measured in kg per cubic meter, or pounds per cubic foot, and not PSI. Drag formulae use density, not pressure.

Third, parachutes don't need a "certain" density to inflate; they need a gas blowing into it to inflate.

Here's the real math:

Mars' atmospheric density at the surface is about .02 kg/m3. The density scale height is 11.1 km. At 100 km the density is about 2.4461e-6 kg/m3.

So at 100 km,
30,000 mph (13,411 m/s),
a parachute coefficient of drag of 1,
a parachute diameter of 10 m (I don't know what it was. 10 meters seems reasonable for demonstration purposes),
and a spacecraft mass of 3893 kg,

would generate 4.4 m/s2 of deceleration. That's about half a g.

To rub more salt into his wound, tell him meteors burn up at an altitude of around 80 kilometer in the Earth's atmosphere. The density at that altitude is equal to the density of the Martin atmosphere at an altitude of 71 kilometers.

#### Rob260259

• Earth
• Posts: 102
##### Re: Curiosity fake...?
« Reply #2 on: August 05, 2013, 05:30:36 PM »
Wow. Thanks. I'm going to get my Japanese friend out of the cabin first and try to catch up a little.

#### smartcooky

• Uranus
• Posts: 1801
##### Re: Curiosity fake...?
« Reply #3 on: August 05, 2013, 07:15:47 PM »
First, it is a known fact that almost all conspiracy theorists are barely capable of adding, let alone multiplying and working with squares.

You have given them far too much credit.
« Last Edit: August 05, 2013, 08:20:09 PM by smartcooky »
► What you can assert without evidence, I can dismiss without evidence
► When you argue with idiots you risk being dragged down to their level and beaten with experience.
► Conspiracism is a shortcut to the illusion of erudition

#### ka9q

• Neptune
• Posts: 3010
##### Re: Curiosity fake...?
« Reply #4 on: August 05, 2013, 08:26:58 PM »
Mars' low atmospheric surface pressure does make it difficult to land with a parachute; you just can't get a survivable terminal velocity from any practical parachute.

That's why every successful lander has used rockets at some point in its terminal descent.  But at the much higher velocities found earlier in the descent, a parachute (and before that, a blunt heat shield) provide plenty of deceleration.

#### ka9q

• Neptune
• Posts: 3010
##### Re: Curiosity fake...?
« Reply #5 on: August 05, 2013, 08:34:58 PM »
It's interesting to note that the average scale height of the earth's atmosphere is only 7.64 km, so the Martian atmosphere, while thin, doesn't fall off with altitude as rapidly as the earth's.

I looked this up. For constant temperature (which is not the case), the scale height is kT/Mg, where k = Boltzmann constant, T = temperature, M = molecular mass and g = gravity. The lower temperature and higher molecular mass of the Martian atmosphere would make the scale height lower than earth except for Mars' much lower gravity of about 1/3 g.

#### Nowhere Man

• Venus
• Posts: 94
##### Re: Curiosity fake...?
« Reply #6 on: August 05, 2013, 08:45:59 PM »
So, does he also believe that the successful landings of Mars 3, Viking 1 & 2,  Mars Pathfinder, Spirit and Opportunity, and Phoenix were also faked?

Fred
Hey, you!  "It's" with an apostrophe means "it is" or "it has."  "Its" without an apostrophe means "belongs to it."

"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684

#### smartcooky

• Uranus
• Posts: 1801
##### Re: Curiosity fake...?
« Reply #7 on: August 05, 2013, 08:52:50 PM »
So, does he also believe that the successful landings of Mars 3, Viking 1 & 2,  Mars Pathfinder, Spirit and Opportunity, and Phoenix were also faked?

Fred

Probably.

Some of these numbskulls actually believe that ALL space-flight is faked because (apparently, according to those very same numbskulls) rockets don't work in a vacuum as they have no air to push against.
► What you can assert without evidence, I can dismiss without evidence
► When you argue with idiots you risk being dragged down to their level and beaten with experience.
► Conspiracism is a shortcut to the illusion of erudition

#### Chew

• Jupiter
• Posts: 545
##### Re: Curiosity fake...?
« Reply #8 on: August 05, 2013, 09:59:31 PM »
It's interesting to note that the average scale height of the earth's atmosphere is only 7.64 km, so the Martian atmosphere, while thin, doesn't fall off with altitude as rapidly as the earth's.

It never occurred to me to think about it that way until I had the insight of comparing the different altitudes meteors would burn up.

With lower surface density but larger scale height, there is an altitude where the density would be the same. For Earth and Mars it's 101 km.

#### Chew

• Jupiter
• Posts: 545
##### Re: Curiosity fake...?
« Reply #9 on: August 05, 2013, 10:12:29 PM »
The OP got it from here: http://www.burlingtonnews.net/spiritmars6.html

Apparently, the same guy believes the atmosphere comes from a reservoir somewhere on the equator that gets sucked up as the Earth spins, centripetal force is linearly proportional to speed, the laws of buoyancy don't exist, our sky is blue because of all the chlorophyll, the inverse square law works by first squaring the ratio then taking the square root, and cameras cannot be made to control the amount of light they receive.

#### gillianren

• Uranus
• Posts: 2023
##### Re: Curiosity fake...?
« Reply #10 on: August 05, 2013, 10:30:59 PM »
Oddly, the one of those that confuses me most is the one about chlorophyll.
"This sounds like a job for Bipolar Bear . . . but I just can't seem to get out of bed!"

"Conspiracy theories are an irresistible labour-saving device in the face of complexity."  --Henry Louis Gates

#### Rob260259

• Earth
• Posts: 102
##### Re: Curiosity fake...?
« Reply #11 on: August 06, 2013, 01:55:04 AM »
So, does he also believe that the successful landings of Mars 3, Viking 1 & 2,  Mars Pathfinder, Spirit and Opportunity, and Phoenix were also faked?

Fred

I already asked him several days ago. I guess he's still hurting his brains on this. As he's also very busy with the 'no crater' issue. I told him about the force impacting the surface of the moon being approx. 20 g/cm^2. And he did not knew about the LM having a throttle to handle that thrust (facepalm

#### BazBear

• Mars
• Posts: 381
##### Re: Curiosity fake...?
« Reply #12 on: August 06, 2013, 02:50:07 AM »
The OP got it from here: http://www.burlingtonnews.net/spiritmars6.html

Apparently, the same guy believes the atmosphere comes from a reservoir somewhere on the equator that gets sucked up as the Earth spins, centripetal force is linearly proportional to speed, the laws of buoyancy don't exist, our sky is blue because of all the chlorophyll, the inverse square law works by first squaring the ratio then taking the square root, and cameras cannot be made to control the amount of light they receive.
Actually it's a woman named Mary Sutherland, "Now Available for Television, Radio, and Lectures"
"It's true you know. In space, no one can hear you scream like a little girl." - Mark Watney, protagonist of The Martian by Andy Weir

#### darren r

• Earth
• Posts: 233
##### Re: Curiosity fake...?
« Reply #13 on: August 06, 2013, 03:50:03 AM »

Actually it's a woman named Mary Sutherland, "Now Available for Television, Radio, and Lectures"

Hoo boy.

It's odd, but I always get the word 'shaman' confused with the word 'charlatan' (I also sometimes say 'fridge' instead of 'lift' but that's another story).
" I went to the God D**n Moon!" Byng Gordon, 8th man on the Moon.

#### Echnaton

• Saturn
• Posts: 1490
##### Re: Curiosity fake...?
« Reply #14 on: August 06, 2013, 08:28:08 AM »
A candidate for the new queen of woo.  Sharing "valuable 'inside' information of which the public and even most researchers are
not familiar with."
The sun shone, having no alternative, on the nothing new. —Samuel Beckett