Earth has captured a second moon, says NASA

Tom Kalbfus · 2016-06-18 18:41:07

-A possible destination for Orion. It gets as close as 9.5 million miles
Earth has captured a second moon, says NASA

A mini-moon has been orbiting our planet for only around 100 years.

Bryan Nelson
June 17, 2016, 4:54 p.m.

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Well, this is awkward. Earth's relationship with the moon is no longer a monogamous one. Scientists have identified a second, mini-moon orbiting our planet that has probably only been around for about 100 years, reports NASA.

This second moon looks to be a recently captured asteroid, and like a mistress, its subtle dance with Earth may be fleeting, only sticking around for a few centuries. Still, it's a remarkable event that proves just how dynamic our gravitational relationship is with near-Earth objects.

The video above showcases in detail the path of the new moon's orbit as it bobs up and down like a tiny float in choppy water. As said, it's small, measuring in at only around 120 feet across and no more than 300 feet wide, which is probably why it has taken so long for scientists to spot it. (It was only just spotted last April.) Its distance from Earth varies from between 38 and 100 times the distance of our planet’s primary moon

Last edited by Tom Kalbfus (2016-06-18 18:44:19)

SpaceNut · 2016-06-18 21:27:23

The size of this object has not yet been firmly established, but it is likely larger than 120 feet (40 meters) and smaller than 300 feet (100 meters). New asteroid, designated 2016 HO3, appears to circle around Earth as well. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or "quasi-satellite."

RobertDyck · 2016-06-18 21:47:02

Not the first.
3753 Cruithne

Horseshoe_orbit_of_Cruithne_from_the_perspective_of_Earth.gif

Can someone tell me the composition of these asteroids? An asteroid that orbits the Sun once per year is as close as you could ask. Now do they have something we could mine for profit?

Tom Kalbfus · 2016-06-19 07:09:55

if it is Earth's distance from the Sun, it likely contains no water, unless it somehow recently got there.

In Figure 3, the most common (modal) value of the distribution falls at 2.63 g/cm3, roughly the density of quartz, an abundant rock-forming mineral. Few density values for these upper crustal rocks lie above 3.3 g/cm3.

If this rock is 40 meters in diameter, that is 4000 centimeters which is 64,000,000,000 cubic centimeters which would weigh 168,320 metric tons, lets say its 200,000 metric tons as the low estimate.

If it is 100 meters across it would weigh 3,125,000 metric tons. You know this mass is roughly equivalent to one of Gerard O'Neill's proposed Space Colonies, probably one of the smaller ones such as the Stamford Torus or the Bernal Sphere. We got all the material already out there, we don't even need to mine it from the Moon! What are the chances of converting it to an actual space colony, lets say the Bernal Sphere for instance? Lets say we build it in place, in the orbit it now stands in, what would the say the difficulties would be?

9.5 million miles (15,288,768 km) About 51 light seconds away 1.7 minutes time delay.

RobertDyck · 2016-06-19 08:28:59

Astronomers have been busy; they discovered more resonant near-Earth objects.
54509 YORP, (85770) 1998 UP1, 2002 AA29, 2009 BD
and one Earth trojan
2010 TK7

Tom Kalbfus · 2016-06-19 09:17:19

The closer the better, We need constant access to it, sort of like we have with the Moon. that 40 meter to 100 meter rock would be just the right size for building a space colony out of. I think the first step would be to bring a 500 meter wide spherical balloon , it will need an opening 100 meters wide so we can bag this rock, and, then we close the balloon and inflate it around this asteroid. Then we mine the asteroid and move the material to the inside surface of the balloon. I think the balloon would be the framework for a Bernal Sphere colony.

RobertDyck · 2016-06-19 11:29:03

Are any of these asteroids metal? Asteroids rich in iron usually have gold and silver. Those rich in nickel have platinum group metals. Large space colonies are grandiose, near-term is simply mining for profit.

If a metal asteroid has nickel, chrome, cobalt, molybdenum, and aluminum, then we can make Inconel 617. It also required carbon, but that can be imported from a "wet" asteroid harvested for rocket propellant. Transport dry ice and water ice as solids, because they're easy to transport. At the metal asteroid, break water ice into hydrogen and oxygen (melt, electrolysis), and use hydrogen to convert CO2 into water and CO. That CO is used for the Mond process to extract ferrous metals (iron, nickel, cobalt). And CO will be a source of carbon to convert iron into steel. Or produce the alloy Inconel 617. That "super alloy" is a metal heat shield that can enter Earth's atmosphere. An aeroshell made of it can transport ingots of precious metal to Earth's surface. No parachute, no landing rockets, no air bags, no RCS thrusters. Just a dumb metal shell, dropped onto Earth. Aim for an empty desert somewhere, and tell everyone to stay out of the way. If the shell cracks open on impact, that's Ok.

Gold and silver are difficult to separate from each other, so don't. Transport gold/silver alloy ingots, take them to a refinery on Earth for final processing. As long as they're over 98% precious metal, good enough. If they get bent or dented on impact, that's Ok because they'll be melted at the refinery anyway. Or make novelty jewellery with "asteroid gold", which could be between 10 carrot and 18 carrot gold.

So mine asteroid "3552 Don Quixote" for propellant and ices, and much closer metal asteroids for bullion.

Tom Kalbfus · 2016-06-19 11:39:29

So what's the hard part about making a Bernal Sphere colony? if you assume you already have all the material on site, such as this asteroid? Maybe you might need to bring in some water, I don't know. I was thinking of inflating a balloon in space around it, not necessarily so astronauts don't need space suits, but to form a sphere, and then by grinding up rocks, separating them out into certain components an adding water, we could make concrete. We would set the concrete along the walls of the balloon, perhaps by rotating the balloon and then after the concrete hardens we use that as a shell to build other things out of that. We would need to make glass for the windows to let in light, and we'd use the metals to make the mirrors. Maybe some gold could be shipped Earthwards to finance the project, later on we could sell real estate inside the Bernal Sphere.

I guess the only thing we don't have a lot of is labor, perhaps robots can be brought up, 3-D printers that make things out of concrete, perhaps some metal printers. Maybe build a mass driver with 3-D printers perhaps, using excess rubble as propellant to shift this asteroid into a closer orbit around Earth. NASA is far too cautious, look at what its doing compared to SpaceX.

Last edited by Tom Kalbfus (2016-06-19 11:42:27)

RobertDyck · 2016-06-19 13:05:50

Asteroid mining will bring precious metals back to Earth for profit. There is no speculation needed how this will benefit investors; literally tonnes of precious metal bullion dropping out of the sky once every 3 to months or so? I'm expecting 3 tonnes including the aeroshell, because a Soyuz capsule weighs that much. It's easy for private investors to see how they will earn return on investment. Not so easy for a space colony.

However, mining a metal asteroid will leave lots of refined industrial metals at the asteroid site as by-products. You could use that to build a Bernal sphere. Possibly smelt rock from a stony-iron asteroid to make glass. Rock is typically alumino-silicate, which is aluminum oxide and silicon oxide with some impurities such as sodium, potassium, calcium, magnesium. Anorthite and Bytownite are easy to process because they dissolve completely in hydrochloric acid. Those two are high in calcium. Other forms of plagioclase are high in sodium, they deposit a layer of quartz on the mineral grain, the layer is as thin as a soap bubble but enough to stop acid. Alkali feldspars are high in potassium (K). A quick google shows they dissolve in organic acid. So could we purify aluminum and silicon oxide from a stony asteroid? Aluminum could be used to make ALON, the same material as windows of the Cupola on ISS. Silicon could be used for normal glass. Perhaps a single pane of ALON outside for micrometeoroid protection, and glass to contain air pressure.

Consider how big the Bernal sphere will be. And that it will spin for artificial gravity. That means stress in addition to air pressure. I think concrete isn't good enough. I'm thinking nickel-steel for the primary shell, with glass/ALON windows. I say nickel steel because metal asteroids are typically nickel/iron alloy. So this makes effective use of both the metal and stony material of the asteroids. Effective In-Situ Resources Utilization.

GW Johnson · 2016-06-19 13:08:20

Concrete is a whole lot more than ground-up rock. It has to have the right chemistry, and it usually takes a bigger volume of water than it does solids. And they have to be the right size distribution of solids at that. You need gravel and you need fine sand. And you need powdered lime.

And if it is to be loaded in tension, you need reinforcing rods, lots of them, usually steel, and you need proper pre-stressed design with those rods. Concrete alone is only good for compressive loads. It is a lousy material in tension. The reinforcement rods need a much higher tensile stress and a much higher modulus of elasticity than the concrete matrix, or else your rods will be the bulk of your material.

There's no "rock fiber ropes" we could make (even if we had available the energy to melt the minerals and draw out the fibers from the melt) which would have the requisite properties to substitute for steel rebar. Plus, there's no known processes for making rock fiber, which work in vacuum and weightlessness.

The chemistry that we know comes from cooked limestone: unslaked lime. Without that to react with the water, there is no binding, no strength, no nothing. It ain't concrete.

I have never, ever, ever heard that an asteroid was identified to be limestone.

That's the fundamental problem I have with people claiming we can build all these space structures out of asteroids as raw material. Not one person who ever said such a thing has ever explained just exactly how we take these minerals not normally used by humans, and turn them into real engineering materials that have strength and resilience.

As a result, and until someone can explain exactly how we do create such materials, then I think of such claims as nothing but futuristic BS. Not something we can actually do, not for a very long time yet.

On the other hand, these semi-moon asteroid things are something we could reach, probably easier than reaching orbit about Mars, and likely with significantly-shorter mission times. These little small inner solar system objects are most likely pretty devoid of volatiles, and very unlikely to be consolidated bodies. They are most likely loose rubble piles with up to, or even exceeding, 50% void space by volume.

That's the most common asteroid collision threat we face. We need real up-close-and-personal experience trying to tie onto, look inside of, and changing the orbit of, such bodies.

There is your proving ground for asteroid defense. There in turn is a supremely-good reason for having a space program, both unmanned and manned. And almost anything we do along those lines contributes to sending men to all the other destinations, including Mars.

GW

RobertDyck · 2016-06-19 14:44:27

List of meteorite minerals
You're right. No alumino-silicates. There is augite, and some other igneous rocks. Earth has separate rock due to gravity: iron and heavy metals in the core, alumino-silicates for the crust. The Moon has minerals so similar to Earth's crust that scientists have concluded that the Moon was formed by something colliding with Earth. Metal asteroids are believed to have formed in the core of a body large enough to melt its core, and enough gravity to differentiate material. Probably a dwarf planet that broke up. So there should be light crustal material from that dwarf planet, but most of the asteroids are non-differentiated.

So, we have to get glass from the linked list of minerals.

Still, I think GW Johnson shouldn't have much argument with my suggestion of building a space habitat from steel.

Tom Kalbfus · 2016-06-19 20:15:53

I kind of think the real estate we could build in space would have more value than any gold or platinum we may send down to Earth, that gold and platinum has to compete with that mined on Earth, and the idea reminds me of that Disney Cartoon Poccahontas, people getting off the ship and immediately start digging for gold. I don't expect this particular asteroid of be laced with precious metals, precious metals are rare, and it will take some work to find them. If truly a large portion of this asteroid was precious metals, I'd worry about those precious metals becoming not so precious. The value of gold is almost entirely in its scarcity. Of more interest would be those materials for which there are industrial uses, but I think the most valuable thing of all is this asteroid's location, it is a source of raw materials from which we can build things in space. It might be enough to get us started on that vision of Space colonization that Gerard O'Neill had. I've been reading this stuff since the 1970s, and I would like to see this get started before I die of old age! it is 2016 for God sake, I'd like to see more than a piddling rehash of Apollo on Mars. I'd like to see people getting off this planet in large numbers, and for space travel to become common place, rather than a Big Deal with government funding of billions of dollars. I would like to see a time where an average middle class person, who is not working for NASA, can simply buy a ticket and travel in space, maybe even live there!

SpaceNut · 2016-06-26 21:27:02

There is a value in these small rocks if they do hold precious metals but even if they do not they are the building materials for the space habitations to be built from....

We are capable of find these ores with satelite mapping
http://www.space.com/13247-moon-map-lunar-titanium.html
http://earthobservatory.nasa.gov/Featur … ospecting/
http://www.nasa.gov/home/hqnews/2009/se … Light.html

RobertDyck · 2016-06-26 22:46:25

Precious metals have a market right now. There is no market for space real estate.

I looked for analyses of meteorites. My assumption was meteorites are a reasonable sample of Near-Earth-Objects. Metal asteroids have a low concentration of precious metals, but ferrous metals (iron, nickel, cobalt) can be easily removed by the Mond process. The Mond process also works with some platinum group metals, requiring higher temperatures and some additional reagents. Because asteroid mining involves refining to separate metals from an alloy, not smelting an oxide ore, you can cost effectively extract precious metals in lower concentrations.

Someone posted a list on Wikipedia: Potential targets

Tom Kalbfus · 2016-06-27 08:29:36

You probably don't need the gold and platinum to build a space settlement anyway, they can be sent down to Earth to pay for it perhaps.

SpaceNut · 2016-06-27 17:38:12

The space real estate market only happens through ownership of the body and not just the minerals that you can take from it with the outer space treaty needing to be altered before ownership can happen.

GW Johnson · 2016-06-27 17:40:23

There is as yet no identifiable market at all. Flooding the market here on Earth with asteroid platinum just makes that very platinum worthless down here.

This in-space mining thing is done as an article of faith, same as it was 500 years ago. The markets for things are unimaginable, before you go. But they have always eventually proved to be there.

Face up to that. You'll be better off, if you do.

GW

Last edited by GW Johnson (2016-06-27 17:41:14)

Tom Kalbfus · 2016-06-27 22:01:03

GW Johnson wrote:

There is as yet no identifiable market at all. Flooding the market here on Earth with asteroid platinum just makes that very platinum worthless down here.

Platinum has industrial uses, among them are in hydrogen fuel cells, if we could make platinum cheaper, then fuel cells would be cheaper. Also platinum does not corrode, it is one of the least reactive metals, even less reactive than gold. You could drop in in a vat of sulfuric acid, and it would stay shiny. Platinum would be great for "silverware" it would never tarnish, it has a high melting point, and it is very dense, denser than mercury, it would sink to the bottom while lead would float on top.

This in-space mining thing is done as an article of faith, same as it was 500 years ago. The markets for things are unimaginable, before you go. But they have always eventually proved to be there.
Face up to that. You'll be better off, if you do.
GW

RobertDyck · 2016-06-28 06:08:21

GW Johnson wrote:

There is as yet no identifiable market at all. Flooding the market here on Earth with asteroid platinum just makes that very platinum worthless down here.

Asteroids are just another ore body. That argument could be made every time any new mine is opened. Yet a lot of mines operate, a lot of companies make money. The market has not collapsed.

Earth already passed peak oil. That means maximum oil production per year. The result does not mean no oil at all, it means gradually declining production. Various forces have fought against this; Canada harvests tar sands and the United States now harvests shale oil. Off shore oil platforms are now drilling in deep water, and drill deep under the surface where oil is high pressure. Deepwater Horizon demonstrated the danger of that in 2010. We can't afford to waste what we have. That means heavy oil must be cracked to form useful products like gasoline and diesel fuel. And natural gas must be harvested, either used directly or converted to something useful. Off short oil platforms typically burn off natural gas. Platinum group metals act as catalysts to break large molecule heavy hydrocarbons into smaller molecule light hydrocarbons. Metals used are platinum, palladium, and rhodium. Example: heavy oil into gasoline. Iron based catalyst converts light hydrocarbons into heavier ones. Example: natural gas into gasoline. A liquid can be stored much more easily at an off-shore platform.

This means increasing demand for platinum group metals. It isn't just for jewellery. Every catalytic converter has one of those same three platinum group metals. Hydrogen fuel cells use one of the same metals. So shifting from a fossil fuel economy to sustainable (to use current buzz-words) does not get you off platinum. There is an increasing demand.

Last edited by RobertDyck (2016-06-28 11:17:13)

GW Johnson · 2016-06-28 08:47:19

What I was talking about is the market for metals like platinum from space.

For the forseeable future, those cannot be cheap.

It costs a lot of money just to send something out there. It will cost a lot to extract the metal, especially since we as yet don't really know how. Oh there are ideas, but the best one cannot be identified until all are tried in some way. It'll cost a bit more to bring the product home, although that is likely the cheapest part.

We'll have more of it, yes, but don't hold your breath waiting for significantly lower prices.

GW

Tom Kalbfus · 2016-06-28 09:28:22

It requires automation. This is one small asteroid that's out there, there are others, but for this one small asteroid, the best use may be to make something useful out of it, that we can boot strap to do greater things. this asteroid is well placed. Maybe we can work with it where it is. Moving it significantly may be beyond our capacity until we learn to build things like mass drivers in space.

GW Johnson · 2016-06-28 09:43:52

Of all the NEO's, one semi-orbiting the Earth like that is the easiest one to reach, Tom is certainly correct about that.

It might even be reachable on an Apollo-like timescale, which means that SLS/Orion or perhaps even Falcon-Heavy/Dragon v.2 could reach it with men.

This is a very good target we can reach with what we have right now. It's a good place to start learning how to extract things from such objects. It might also be a good place to experiment with deflecting them, too.

GW

Last edited by GW Johnson (2016-06-28 09:44:44)

RobertDyck · 2016-06-28 11:25:33

Tom Kalbfus wrote:

Moving it significantly may be beyond our capacity until we learn to build things like mass drivers in space.

No "until". You will never move something as large as a mountain. If you could develop the technology, it would be a very bad idea. Moving a mountain requires massive reaction mass. Using something inefficient such as a mass driver throwing rockets from the object, would lose most of the mass of the object. We know how to move a mountain, mining companies do it today, one truckload at a time.

Tom Kalbfus · 2016-06-28 12:30:22

https://en.wikipedia.org/wiki/Mass_driver

Spacecraft-based mass drivers[edit]
A spacecraft could carry a mass driver as its primary engine. With a suitable source of electrical power (probably a nuclear reactor) the spaceship could then use the mass driver to accelerate pieces of matter of almost any sort, boosting itself in the opposite direction. At the smallest scale of reaction mass, this type of drive is called an ion drive.
No absolute theoretical limit is known for the size, acceleration or muzzle energy of linear motors. However, practical engineering constraints apply for such as the power to mass ratio, waste heat dissipation, and the energy intake able to be supplied and handled. Exhaust velocity is best neither too low nor too high.[17]
There is a mission-dependent limited optimal exhaust velocity and specific impulse for any thruster constrained by a limited amount of onboard spacecraft power. Thrust and momentum from exhaust, per unit mass expelled, scales up linearly with its velocity (momentum = mv), yet kinetic energy and energy input requirements scale up faster with velocity squared (kinetic energy = 1⁄2 mv2). Too low exhaust velocity would excessively increase propellant mass needed under the rocket equation, with too high a fraction of energy going into accelerating propellant not used yet. Higher exhaust velocity has both benefit and tradeoff, increasing propellant usage efficiency (more momentum per unit mass of propellant expelled) but decreasing thrust and the current rate of spacecraft acceleration if available input power is constant (less momentum per unit of energy given to propellant).[17]
Electric propulsion methods like mass drivers are systems where energy does not come from the propellant itself. (Such contrasts to chemical rockets where propulsive efficiency varies with the ratio of exhaust velocity to vehicle velocity at the time, but near maximum obtainable specific impulse tends to be a design goal when corresponding to the most energy released from reacting propellants). Although the specific impulse of an electric thruster itself optionally could range up to where mass drivers merge into particle accelerators with fractional-lightspeed exhaust velocity for tiny particles, trying to use extreme exhaust velocity to accelerate a far slower spacecraft could be suboptimally low thrust when the energy available from a spacecraft's reactor or power source is limited (a lesser analogue of feeding onboard power to a row of spotlights, photons being an example of an extremely low momentum to energy ratio).[17]
For instance, if limited onboard power fed to its engine was the dominant limitation on how much payload a hypothetical spacecraft could shuttle (such as if intrinsic propellant economic cost was minor from usage of extraterrestrial soil or ice), ideal exhaust velocity would rather be around 62.75% of total mission delta v if operating at constant specific impulse, except greater optimization could come from varying exhaust velocity during the mission profile (as possible with some thruster types, including mass drivers and variable specific impulse magnetoplasma rockets).[17]
Since a mass driver could use any type of mass for reaction mass to move the spacecraft, a mass driver or some variation seems ideal for deep-space vehicles that scavenge reaction mass from found resources.
One possible drawback of the mass driver is that it has the potential to send solid reaction mass travelling at dangerously high relative speeds into useful orbits and traffic lanes. To overcome this problem, most schemes plan to throw finely-divided dust. Alternatively, liquid oxygen could be used as reaction mass, which upon release would boil down to its molecular state. Propelling the reaction mass to solar escape velocity is another way to ensure that it will not remain a hazard.

It seems like this is something NASA has not tried

GW Johnson · 2016-06-28 13:24:03

Mass drivers are still a science lab project, not an actual deployable technology. Needs a lot of development work. The closest item is the rail gun. I notice that it is not yet deployed yet with the navies of the world, except as an experimental item here and there. That should tell you something.

GW

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Earth has captured a second moon, says NASA

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