(100 year). Project to Increase Earth's Mass. (maybe !)

[RJSV]

   It's the ultimate Disruptive technology (OT,  sorry).
   The science might indicate some subtle factors where Earth bound farms and forests would benefit.  Now, since this is currently speculation,  I'm not really prepared with conclusions.
   TV show on science and asteroid minerals did mention the potential for ruination of rare metals markets,  by flooding GOLD,  PLATINUM,  and other currently attention grabbing possibilities.
   But,  now,  that's going to mean a lot of space re-entries, (down to sea level.)

  Maybe the concept itself,  of mineral 'farming' from SPACE,  could start some brainstorming on how and why... why's an increase of the mass of our Earth, COULD maybe alter growth patterns,  air quality,  etc.
   This meaning a LOT of years in the future, with social and technological factors favor smart planned mega-projects.

   Otherwise,  lacking sofisticated social cooperation there might be endless political disruptions and protests...
Adding 20 % mass to Earth might trigger some massive objections,  and the idea of using force isn't palatable.

   The methods themselves are relatively simple,  assuming 'Space Tugs' etc. in 2124.
Simply grab a rock,  put in bin,  repeat.
Automated harvest bot would collect,  travel to near-Earth,  then DROP LOAD.
The tug-bots could, also,  grab a little GOLD,  for later transport back to earth,...(or where ever needed).

   1.). More Earth mass,  thus longer day,  less atmosphere loss (? Huh?),  but with some temperature rise.

   2.). Maybe use this 'disruptive technology' on Mars...Might already been discussed, by various NASA or even by fiction writers like Robert Heinlein.

Thanks for reading !

[themadhippy]

. More Earth mass,  thus longer day,

Bet this has been dreamed up by clock manufacturers to force us all into buying  new 25 hour clocks

[Kleinstein]

Bringing back material from space to earth is expensive. One needs to send up a space craft with heat shield just to bring the material back. Currently it is questionable to bring things back from earths orbit that are less valuable than gold. The fast and hard way for a right size (e.g. some 100 tons) block of precious metal may work but can be risky if it hits the wrong place.

The value of the rare earth materials to a large part comes from the chemical separation between the different elements. The allways come together in mix (usually also with thorium, that adds some issues to the waste).  I very much doubt it would sensible to do the chemistry in space or bring back the mixture, where only a small fraction really has value. Just finding and digging up the minerals is relatively cheap. They are not really rare.

No way would one add a significant mass to the earth - chances are the rockts send out and never return would loose more mass.

[jpanhalt]

Source: https://www.scientificamerican.com/article/antarctic-study-shows-how-much-space-dust-hits-earth-every-year/

When it scaled up the Dome C measurements to the entire planet, the team found that between 4,000 and 6,700 metric tons of space dust falls to Earth each year.

What burns up also adds to our mass.

[RJSV]

Interesting.  Wonder what the long term balance is, between atmosphere blow-off losses and additional dust weight ?
The rare minerals thing is just one additional perk.

   IF,  it's 10 tons per year of dust coming in,  along with, say, guessing 3 metric tons of atmosphere blow off (from solar flares, etc.), then that's 7 tons net gain.

   So first question is what does that weight gain contribute to Earth rotation increased time ?
So...that weight change has been going on for a long long time.

   What if the 'project' contributes 100 tons per year, or ten times increase ?
Each BOT just automatically goes to asteroid belt and brings back some mass.  Electric 'space drive',  amoung hundreds of other fetch-bots.

   Can you just be tracing towards Earth,  up close,  and, like 'Fling' a cache of rocks ?
Or,  do they require a de-orbit burn ?
 
Haha,  might backfire by adding angular momentum...(Oops).

[Analog Kid]

Oh, c'mon Rick: don't be ridiculous. (DeRickulous?)

Think about it: how much mass would have to be added in order to increase the Earth's total mass by, say, 0.00000001%?

Pure sci-fi BS speculation here.

[coppercone2]

Sure you can, by building a giant mass driver on the moon, then you can shoot big metal slugs into the indian ocean. they might do it one day when they have a ecological colamity after someone steals all the maganese nodules

fusion reactor to turn regolith into metal to shoot at the earth

it might even be a way to seed life in wet planets

[tszaboo]

Simply grab a rock,  put in bin,  repeat.

You dont understand orbital mechanics. Like, at all.

It's the same stupidity like the people who want to throw trash into the sun. Don't even get me started.

[RJSV]

   Well,  Iay out some estimates,  and rack up the positives, (first),  and in light of desired advantages.   THEN I start examining any negatives, or pesky physics.

   I believe there's a high energy penalty, in attempting to travel to the meteor just to grab some mass.   Tempting to,  knee-jeek,  claim electric space travel, by 2030.  But that would just be teasing.

   Hundred year deadline helps,  plus many many fetch-bots.   How much weight or mass is that figure, BTW ?
   (The 0.0000001 % of Earth's Mass ?)

Or,  shall I go figure out that ?
It's got to be having some angular velocity effect,  no ?  Like 2.4 seconds lost per year,  (naturally, over the last millennium.)

Solar-Fricken fetch bots.  That could end up in revolution with rocks thrown (at Earth).
I think that idea comes from a sci-fi book,  vaguely...

[jpanhalt]

Interesting.  Wonder what the long term balance is, between atmosphere blow-off losses and additional dust weight ?

It's complex, we also capture gases.

Source: https://www.britannica.com/topic/evolution-of-the-atmosphere-1703862/Sinks

For Earth, this velocity is 11.3 km (7.0 miles) per second, and it follows that, once the solid material had accumulated, gas molecules passing Earth at lower speeds would have been captured and accumulated to form an atmosphere.

[Analog Kid]

How much weight or mass is that figure, BTW ? (The 0.0000001 % of Earth's Mass ?)

Well, Rick, I'll start you off on your homework by giving what the all-seeing oracle "Google" told me:
The mass of the earth is 5.972 × 10²⁴ kg.*

* Do "they" (meaning pointy-headed scientists) really know that to a certainty?
I mean, it's an estimate. Wonder how accurate that is ...

[TimFox]

Google “Cavendish balance experiment” (1798).
Determining the universal gravitational constant G and comparing to the acceleration g gives the density of the Earth.

[Analog Kid]

Google “Cavendish balance experiment” (1798).
Determining the universal gravitational constant G and comparing to the acceleration g gives the density of the Earth.

OK, I found this page describing that experiment (NOT Wikipedia! this is from Harvard U).

So they used a couple of lead dumbbells to measure the gravitational attraction between them.

What I want to know is, how accurate are the results of this experiment?

I mean, there's the possibility of error in any measurement, right? And if multiple measurements are required in an experiment, the errors are compounded.

So what do you figure the accuracy of this gravitational constant is? Is it within an order of magnitude? And is it within reason to further use it to compute the mass of the Earth, which is an enormous thing?

[RJSV]

   Thanks for the numbers,  everyone.  Please keep in mind;  We play to a rather large audience,  some brief guests,  but a tiny bit of bad info,  or other factors that degrade the experience,  has a huge multiplying effect.
   I taken to use the retail business model,... where any reader is 'a client'.
   Point being,  Iike the orbital physics stuff,  and many many others,  also wish to follow the numbers and conclusions.
So going into detail is a good trade,  time spent vs. info transfered.
   
   I completely missed the solar orbit,  affecting the length of one year.   But for just the Earth spin,  it's simple momentum (angular).
That's assuming a random distribution,  of which arrival direction happens.  Meaning no real contribution by collision.

   I'm assuming that angular momentum is conserved (over longer term).
Momentum being:
     'MASS X VELOCITY',
Or,  in this case, that's the rotational angular velocity.  (That's in radians per second.)
 
So,  with mass streaming down,  it is adding to the mass,  when momentum stays (conserved).
Thus,  the planet's spin or angular speed must decrease.

   I keep hoping a GPS expert can chime in,  as they track the tiny changes,  in natural spin,  for purposes of time coordination.

   Honestly,  I'm not sure how to calculate effect on solar orbit.  Seems like should be similar to the Earth self-spin (24 hours) ?
That's going to decrease the velocity,  (for every additional gram of mass).
  ?  That causes orbit to move to larger path ?

Not sure on that,  but apparently makes for a longer period.

[TimFox]

Cavendish experiment:  Britannica quotes the modern value G = (6.6743 +/- 0.00015) x10^-11 m³ kg^-1 s^-2.  Cavendish himself calculated the mean density of the Earth as 5.48 g/cm³, vs. the modern value of 5.51 g/cm³.  To get the mass, one needs the radius of the Earth, corrected a bit for non-spherical geometry.  Very reasonable.

[tszaboo]

   Well,  Iay out some estimates,  and rack up the positives, (first),  and in light of desired advantages.   THEN I start examining any negatives, or pesky physics.

   I believe there's a high energy penalty, in attempting to travel to the meteor just to grab some mass.   Tempting to,  knee-jeek,  claim electric space travel, by 2030.  But that would just be teasing.

   Hundred year deadline helps,  plus many many fetch-bots.   How much weight or mass is that figure, BTW ?
   (The 0.0000001 % of Earth's Mass ?)

Or,  shall I go figure out that ?
It's got to be having some angular velocity effect,  no ?  Like 2.4 seconds lost per year,  (naturally, over the last millennium.)

Solar-Fricken fetch bots.  That could end up in revolution with rocks thrown (at Earth).
I think that idea comes from a sci-fi book,  vaguely...

If you want estimates, I can give you one. You need the equivalent delta V to get to LEO as to get to the asteroid belt and to get back from there. So to bring back a Hundred ton asteroid, you need a rocket like the Saturn V at the belt. So a rocket about six hundred times larger on earth to bring back some weight, that will be as useful as some sand on the beach.