Reasons why LCROSS is a safe mission

  • Context: High School 
  • Thread starter Thread starter MajorHarrison
  • Start date Start date
Click For Summary

Discussion Overview

The discussion centers around the safety of the LCROSS mission, which involves crashing a spacecraft into the Moon. Participants explore various arguments and analogies to explain why this mission poses no danger to Earth or the Moon, addressing concerns raised by individuals outside the physics community.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Meta-discussion

Main Points Raised

  • Some participants argue that the mass of the Moon is so large compared to the LCROSS spacecraft that the impact will have negligible effects, using analogies like a fly hitting a house.
  • Others suggest that the frequency of natural impacts on the Moon from larger objects demonstrates that the LCROSS impact is safe and inconsequential.
  • A participant mentions that many users on a non-physics forum expressed concerns about the mission being dangerous, specifically fearing that the Moon could crash into the Earth.
  • Some participants propose that the analogy of crashing a truck into the Earth illustrates how the Earth would not notice the impact of the LCROSS mission.
  • There is a discussion about visibility of the impact plume, with some participants expressing confusion over who would be able to see it based on their geographical location.
  • One participant shares their experience of attempting to observe the impact but reports not seeing any plume, raising questions about the visibility of the event.
  • Another participant references NASA's confirmation of water on the Moon as a related point of interest stemming from the mission.

Areas of Agreement / Disagreement

Participants generally agree that the LCROSS mission is safe and that concerns about it causing harm are unfounded. However, there is disagreement regarding the effectiveness of analogies used to explain this safety and the visibility of the impact plume, with some expressing skepticism about whether it could be observed at all.

Contextual Notes

Some participants highlight the limitations of analogies in conveying the scale of the impact and the complexities of orbital mechanics. Additionally, there are unresolved questions about the visibility of the impact plume, as experiences and observations vary among participants.

Who May Find This Useful

This discussion may be of interest to individuals curious about space missions, the safety of scientific experiments, and the public perception of such missions, particularly those who may have concerns about the implications of space exploration.

MajorHarrison
Messages
2
Reaction score
0
Hi everyone. I'm looking for some help explaining why the LCROSS mission is perfectly safe. If you don't know what I'm talking about you can find an article http://www.siliconvalley.com/ci_12590357" helpful (post #11). What I am basically looking for is a way to explain to a person who doesn't know that much about physics why there is nothing to worry about for this mission.
If any of this is wrong, please correct me.

PS. This is my first post here so be nice.
:smile:
 
Last edited by a moderator:
Astronomy news on Phys.org
Hello, and welcome to PF!

You are correct, there is no chance of the moon crashing into the Earth or anything like that. Without going into the details of orbital mechanics, momentum, and energy, you can just concoct some analogy (a fly running into a house, or something) to demonstrate that the moon is so much terribly more massive than a puny rocket. If analogies aren't your bag, explain that countless asteroids have bombarded the Moon's surface, many much more massive and traveling much faster than this rocket will. Mind you this happened billions of years ago, and as far as I know, the moon is still there.

Somewhat akin to the argument against the LHC creating mini black holes, because much higher energy cosmic rays have been bombarding the earth, and so if the creation of mini black holes was possible (and dangerous) we wouldn't be here right now.
 
Nabeshin said:
you can just concoct some analogy (a fly running into a house, or something)
That's a bit better than the BB versus a bowling ball analogy, but not much. LCROSS masses 1664 lb. A house fly: 12 mg, or about 1/63000 of the mass of the LCROSS. Scaling the Moon's mass by the same amount yields a better analogy: A house fly running into a *big* brick that weighs 1.3×1015 tons. That doesn't say much yet. The Empire State Building has a mass of 365,000 tons. That brick is equivalent to 3.5 billion Empire State buildings. A fly flying at 5,600 mph into a pile of 3.5 billion Empire State buildings is not going to move the pile at all.
 
Nasa is going to crash a spacecraft into the moon!
What about the clangers ?

card.jpg
 
"I am on another forum (not a physics focused forum) and this article was posted. Many of the users there started saying that they think this is a dangerous mission and the moon will "crash into the earth"."

Tell them to watch the video that's embedded in the article. It explicitly says that the LCROSS is schoolbus-sized, and that schoolbus-sized objects crash into the Moon every month. To use an analogy, launching LCROSS at the Moon is like crashing a truck into the Earth. Earth will not notice at all.
 
Ok, thank you all for your responses. I am sure this will convince them its safe.
 
No, it won't. It is rather difficult to win an argument against woo-woos. They are completely immune to logic and evidence.
 
Get your telescopes out if you are west of the Mississippi (Dam, my scope is in Upper Michigan).
The LCROSS impact plume should be visible in a 10 inch and larger scope.

Someone please take some pictures and post them here.

October 9
4:30 am PDT

http://science.nasa.gov/headlines/y2009/05oct_lcrossvg.htm?list1032821"
 
Last edited by a moderator:
There's plenty of readers of this forum 'west of the Mississppi' who won't be able to see this impact.
 
  • #10
Wallace said:
There's plenty of readers of this forum 'west of the Mississippi' who won't be able to see this impact.

I am a bit confused, why won't they be able to see it?
Or was that a typo.
 
  • #11
Because the Moon will be on the other side of the Earth at that time. I am, for instance, west of the Mississippi (I'm also east of it) but it will be broad daylight for me when this impact happens.

The world, and this forum, exists far beyond one continent!
 
  • #12
I guess East and West have no meaning what so ever then in that sense.
I should have just said if someone is in the right place at the right time please take some pictures.

We have about 20 minutes until impact NASA TV has it live if anyone wants to watch.
 
  • #13
Special Feed Here also:

http://www.slooh.com/special_feed.php
 
Last edited by a moderator:
  • #14
Sorry to appear pedantic, but my east-west thing may have obscured my point. Think of how usefull it would be, and how silly it would sound, to you if I posted that something could be seen if you 'are west of the Nile' or by anyone 'east of the Rhine'.
 
  • #15
Somebody from NASA could have told us how boring that was.
 
  • #16
This might be a silly question, but are the images located http://www.telegraph.co.uk/science/space/6275279/Nasa-Moon-bombing-LCROSS-mission-crashes-into-Moon.html#" real?

Are these images that the 'lagging' spacecraft took?
 
Last edited by a moderator:
  • #17
Anyone has a picture of the plume?
 
  • #18
pixel01 said:
Anyone has a picture of the plume?

I'm not sure that even NASA saw much of a plume visually. I watched with an 8" Schmidt-Cassegrain (at 8:31 am my time), and I didn't see anything.

My little girl woke me up at 5:00 am to go pee. After taking her to the bathroom and getting her back to sleep, I carried my gear down two flights of stairs and locked it in our car (parked on the street) to cool down. At 7:30, the sky was almost completely cloudy. Started to clear at about 8:00, so I went out and set everything up. Still clear at 8:31 and the Moon was high in the sky. The seeing was fairly steady, and I had a clear view of the area at my highest magnification, 254x. Saw nothing, but I'm not a great observer, and, by 8:31, the features were somewhat washed out by daylight.
 
Last edited:

Similar threads

High School Why does the flag on the moon appear to be waving during the Apollo 13 mission?
  • · Replies 31 ·
2
Replies
31
Views
9K
High School Discussing Juno/JunoCam Mission and Jupiter Data
  • · Replies 112 ·
4
Replies
112
Views
18K
Human factors, technology and deep space missions
  • · Replies 7 ·
Replies
7
Views
2K
High School Where Can I Find Accurate Planetary Event Data for an Astronomy Course?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad A manned mission to Mars and its obstacles
  • · Replies 5 ·
Replies
5
Views
9K
High School Help w/ repairing/refurbishing an equatorial mount
  • · Replies 11 ·
Replies
11
Views
3K
High School What Are the Implications of Space Being the Ideal Medium for Light?
  • · Replies 2 ·
Replies
2
Views
2K
Writing: Input Wanted A dangerous space mission that requires a lot of helping hands
  • · Replies 22 ·
Replies
22
Views
4K
Studying Interested in Astronomy as a Freshman
  • · Replies 20 ·
Replies
20
Views
1K
Classical The best introductory mechanics textbook
  • · Replies 39 ·
2
Replies
39
Views
9K