Unconfirmed near-Earth objects

Unconfirmed near-Earth objects
A diagram of the orbits of many known Near Earth Objects. Astronomers have estimated that about 18 percent of reported NEOs have been unable to have confirmation observations. Credit: NASA

Near-Earth objects (NEOs) are small solar system bodies whose orbits sometimes bring them close to the Earth, potentially threatening a collision. NEOs are tracers of the composition, dynamics and environmental conditions throughout the solar system and of the history of our planetary system. Most meteorites come from NEOs, which are thus one of our key sources of knowledge about the solar system's development. Because some of them are easier to reach with spacecraft than the Moon or planets, NEOs are potential targets for NASA missions. The total number of known NEOs exceeds 18000. The discovery rate has risen rapidly recently, driven by in part the 1998 mandate of Congress to identify 90 percent of NEOs larger than 1 km (in 2005 Congress, recognizing the danger posed even by smaller NEOs, extended the mandate to sizes as small as 140 meters.)

The importance of NEOs for science and safety has emphasized the need for accurate statistics of the population – but there is a problem. The discovery process for NEOs requires distinguishing between known and unknown targets, and then following up previously unknown targets to measure their orbits. The catalog of orbital elements of known NEOs, their size-frequency distribution, as well as the region of sky visited by telescopes, all serve as inputs for deriving debiased population models. But many NEOs are spotted and reported, but follow-up observations are not done.

CfA astronomers Peter Vereš, Matthew Payne, Matthew Holman, Gareth Williams, Sonia Keys, and Ian Boardman (all are affiliated with the Minor Planet Center at the CfA) and a colleague have analyzed the NEO reports from 2013 to 2016; in this over 170,000 objects (including comets) were reported as likely candidates. By tracking down the list of candidates submitted to the minor Planet Center and using statistical tools, the scientists estimate that about 18 percent of all NEO candidates remain unconfirmed. They point to several reasons including delays in reporting the detection; the object is moving, and the scientists found that delaying the initial report from two to ten hours results in doubling the number of unconfirmed detections (the delay makes it more difficult for follow-ups to locate the moving source). Another issue is that unconfirmed NEOs tend to be much fainter and harder to follow up. The scientists conclude that the number of unconfirmed NEO candidates could be large, in the thousands, and emphasize the need for surveys to rapidly submit detection reports.


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Near Earth Objects

More information: Peter Vereš et al. Unconfirmed Near-Earth Objects, The Astronomical Journal (2018). DOI: 10.3847/1538-3881/aac37d
Journal information: Astronomical Journal

Citation: Unconfirmed near-Earth objects (2018, June 22) retrieved 21 September 2019 from https://phys.org/news/2018-06-unconfirmed-near-earth.html
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Jun 22, 2018
Instead of wasting resources and funding on the Moon or Mars? These NEO's are immediately accessible to be used as the materials for automated orbital facilities.

Which in turn would be the basic infrastructure for an expansive exploration of this Solar System.

You want to colonize the Moon or Mars? AOF's feeding off the NEOs are your stepladder.

My advice for the emigrant yearning? Join your nation's navy and gain experience aboard long-range missile submarine service.

Or, you could try living in a cave for a year. With all access to the surface blocked. Forced to survive on what you can make out of your surroundings. Recycling your air and water and bodily wastes. Don't have an appendicitis attack. Or, crack a tooth. Or, complications during childbirth. Or, run out of comicbooks.

Jun 22, 2018
'Spaceweather' carries a list of confirmed NEOs with recent & upcoming encounters. It often makes for unsettling reading...
http://spaceweather.com/

Jun 22, 2018
Or, you could try living in a cave for a year. With all access to the surface blocked. Forced to survive on what you can make out of your surroundings. Recycling your air and water and bodily wastes. Don't have an appendicitis attack. Or, crack a tooth. Or, complications during childbirth. Or, run out of comicbooks.


All of this, of course, WITH evolved tech ensuring none of the problems mentionned ever cause problems and is unsolvable or end in tragic conclusions, right?
Thanks for the precisions, rrwillsj. Your contribution is a real strawberry on a creamy pie.

Jun 22, 2018
These NEO's are immediately accessible to be used as the materials for automated orbital facilities.

Not really. To put something in orbit you have to change its velocity to match that of Earth. With an object 1km in size that's far outsid the range of what current tech can do.

Jun 22, 2018
Yes a_p, you are correct today. That is why I advocate baby-steps. Begin with collecting some of the LEO trash to use as reaction mass to push a small drone to intercept a small bit of stellar debris in higher orbit.

Each event, bootstrapping off what is accessible at that moment. Nothing grandiose, nothing needing unobtanium or superpowers.

Huh, I just thought. Some clever enterpriser could rent out a fleet of drones to earthsiders wanting to experience joysticking a space mission in real time. From the comfort and safety of their own home.

Oh, and Ed, you might try reading the personal accounts of real pioneers. Visit their cemeteries and check out the ages listed on their gravestones. If you don't cry? You got no heart.

The uncomfortable realities of Life and death that are left out of the comicbooks.

Jun 22, 2018
Not really. To put something in orbit you have to change its velocity to match that of Earth. With an object 1km in size that's far outsid the range of what current tech can do.

You could refine one of those things with concentrated solar energy, vaporise it essentially to get what is most valuable in it and then bring that to Earth. Cheap stuff like iron or aluminium would be good only if used on site.

Actually you could use cheap stuff to propel the asteroid on orbit around Earth... But I think it may not be too smart to condense that stuff back into the asteroid, just in case it deorbits and falls on Earth. It would be nasty to have an iron fist instead of a rock falling down here.

Jun 22, 2018
STOP WORRYING About & WASTING Money on Mars IMMEDIATELY.
Start Think of Bringing to Earth The Nearest and Smallest Asteroid as/for Practice. Then, Focus on Asteroid With Abundant Rare Earth Minerals !
Make sure you prove first that they did not cheat everybody that they went to Moon half a century ago.
Otherwise, tomorrow they will cheat again that have gone to Mars Too !

Jun 22, 2018
You could refine one of those things with concentrated solar energy, vaporise it essentially to get what is most valuable in it and then bring that to Earth.

While marginally better I still don't see this as currently anywhere near feasible.

To do this you would have to transport, (and land safely,...and install)
- mining gear
- smelting gear
- a substantial(!) power source
- a railgun to get these ingots to earth velocity (and then what?)
(oh...and all of this has to be fully robotic and maintenance free.)

Getting a 1km size asteroid to Earth velocity might take a ludicrous amount of energy, but getting all the above stuff to such an object's velocity is also way, ways, WAY more than we've ever done in space.. Seriously. We're talking maybe 5-6 orders of magnitude, here.


Jun 22, 2018
You could refine one of those things with concentrated solar energy, vaporise it essentially to get what is most valuable in it and then bring that to Earth.

While marginally better I still don't see this as currently anywhere near feasible.

To do this you would have to transport, (and land safely,...and install)
- mining gear
- smelting gear
- a substantial(!) power source
- a railgun to get these ingots to earth velocity (and then what?)
(oh...and all of this has to be fully robotic and maintenance free.)

Getting a 1km size asteroid to Earth velocity might take a ludicrous amount of energy, but getting all the above stuff to such an object's velocity is also way, way, WAY more than we've ever done in space.. Seriously. We're talking maybe 5-6 orders of magnitude, here.


Jun 22, 2018
Lets start wrangling us some meteors !

we'll send american cowboys and gauchos from brazil . and we can catch one ... check to see if it has any valuable minerals.. and if not.. toss it in the sun.

we will establish a whole new culture.

Jun 22, 2018
Okay, I gotta be more precise.

A small rock or amalgamate less than one ton mass. Probably less than 100 Kg to start with. Whatever materials it consists of? Are too valuable while in Space, to be wasted by sending down to Earth.

As well as, who wants it falling on their head? And if they find it before you catch up with it? I imagine, finders keepers and you can go peddle your papers while searching for a sympathetic court.

"But the gold! You exclaim." You've heard of EFT? That's how most bullion investments are handled today. The owners never ever get to touch the London Good Delivery Bars. Why take unnecessary security risks? No street thug will be robbing a deep space probe containing a quantity of gold shielding. But you can still buy and sell ownership of that gold and any other material being used.

All I am advocating is applying common sense and meticulous development. Sorely lacking among those dreaming of interplanetary conquest.

Jun 22, 2018
rrwillsj, NEOs COME NEAR Earth, but they are not as consistently near Earth as Luna is. That consistent short communication delay is a big point in favour of the moon for robotic operations and early bases.

Jun 22, 2018
Gigel
"You could refine one of those things with concentrated solar energy..."

You will never see solar concentrators used in space, or on the Lunar surface. Wait and see.

Jun 22, 2018
Gigel
"You could refine one of those things with concentrated solar energy..."

You will never see solar concentrators used in space, or on the Lunar surface. Wait and see.


Oh? And why would that be? Hmm?

Jun 23, 2018
Although this is more about the original article than the current comments, it is worth noting.

TESS has been launched and is on its way to its final orbit. While the intent is to find planets around nearby stars, it will also detect and need to characterize lots of asteroid orbits. The Gaia satellite has a different mission but the same all sky detection of asteroids. Why are these such good asteroid hunters? Asteroids are much brighter in the infrared than most stars, but doing IR astronomy from Earth is difficult. The WISE spacecraft was repurposed as NeoWISE when it ran out of coolant for its two longest wavelength IR detectors. But it is still great for finding asteroids, including NEOs.

For almost every NEO ever detected there is contemporary data in one of those databases. What is really needed is a project to merge all that data and sort out the NEOs.

Jun 23, 2018
Your illustration caption reads, " A diagram of the orbits of many known Near Earth Objects. Astronomers have estimated that about 18 percent of reported NEOs have been unable to have confirmation observations." If you can't find an actual trained journalist to write captions, how about employing an individual who has studied English, and knows the difference between awkward 'passive voice' writing and using the effective 'active voice'? Try this: "Astronomers....say they are unable to make confirmation observations for about 18 percent of reported NEOs." You can obviously leave out "estimated", which is tautology, since you use the word "about" later, conveying the same meaning. Brevity may be the soul of wit, but education is the basis for literacy and good communication skills.


Jun 23, 2018
Okay, I gotta be more precise
Naw willis you've gotta stop pretending you know what you are talking about and trying to defend your bullshit.
A small rock or amalgamate less than one ton mass. Probably less than 100 Kg to start with. Whatever materials it consists of? Are too valuable while in Space, to be wasted by sending down to Earth
'Whatever materials' ... the vast majority of NEOs are composed of worthless materials. Planets in contrast, like mars, are full of easily-accessible and refinable ores.

Jun 23, 2018
I'm curious otto, those easily-accessible and refinable ores? You have personally surveyed the locations of the ore?

Hey good buddy! Can I have a peek at your map?

And, where thee hell did you get a spacesuit for your burro?

I do agree that a sizable proportion of the orbiting rubble has no value as ore or source of volatiles and carbon.

However the clinkers, slag and grit will have a small value. Either as reaction mass, when aimed judiciously.

Or use as disposable cladding for habitat surface shielding.

If used as counter-weight bulk material in a centripetal habitat? The grit is transportable through out the structure as needed. If vacuum-dry it will not freeze. As used as a heat-sink it wound moderate internal temperatures.

In addition it can also filter air and water and wastes.

Grand schemes of palaces in the clouds are fun. But in real life? It is the niggling little details of logistics that accomplishes the grandiose.

Jun 23, 2018
Well you're right willis let me frame my comment another way... since you're proposing to mine these things, what makes you think there's anything there worth mining?

Jun 23, 2018
Truly otto? I don't have a damn clue whats there until we go look. And as I said, any material already in orbit has value just for it's existence where we do not have to pay to lift against any gravity field.

It is estimated that about 10% of the meteors that become meteorites, consist of nickel-iron. That's why they survive through the atmosphere too bounce across the landscape. If that percentage holds for the NEO's? That's one hell of a lot of good quality metal. Not too far from where it can be put to good use.

Out of the 90%? Mostly stoney gravel pits. Lots of uses for rubble and grit.

Real value will be in the carbonaceous bearing carbons, water-rock and other minerals. For those who want to colonize space, guess whats providing your garden? I hope at least 10% of the NEO's are of this type.

As for actual icebergs? 1% this side of Ceres and Vesta would be a precious discovery. Well worth the effort it would take to chase it down and net it.

Jun 23, 2018
So willis wants to expend gigajoules moving kilotons of dirt multiple AUs across the inner system, all moving at wildly divergent delta V.

Then he wants to expend more gigajoules refining, smelting, fabricating, and assembling something-or-other in orbit. And STILL he has to lift all that machinery up there, and all the people to do the work, and all the materials he cant find but still needs, to complete the task.

And he wants to do this rather than mine and refine on the moon, where megatons of ore can be processed, converted to useful products, and shot wherever we want it. Or just go to mars where all that can be done on the ground and used right there.

You are packed as tightly full of shit as your posts.

And no willis, there is very little use for dirt in space.

Jun 24, 2018
rrwillsj> NEO's are immediately accessible to be used as the materials for automated orbital facilities

antialias_physorg> Not really. To put something in orbit you have to change its velocity to match that of Earth. With an object 1km in size that's far outsid the range of what current tech can do.

Finally, why we can't find planetary civilisations, were far outside the range of what current tech can do
We can't mine NEOs is indicative of our ability to travel the Galaxies is why were not coming into contact with planetary civilisations before you default to your ideology antialias_physorg life on earth is intrinsically linked with our ability to travel the Galaxies
We can't step foot on the moon sending transporters to travel 250,000miles at a 100,000mph landing on the moon in 3 hours and be back home after lunch with those rock samples antialias_physorg is why we cannot avoid extinction from NEOs and why those NEOs are prohibitively expensive to mine

Jun 24, 2018
Propositional logic and Rocket propellant as barrier to travelling the vacuum of space
rrwillsj
TheGhostofOtto1923
antialias_physorg
antialias_physorg has nailed it "were far outside the range of what current tech can do" where are currant tech relies on 1000s of years old Chinese tech
As long as we continue to use rocket propellant we are never going to travel the galaxies, never going to come into contact with planetary civilisation and any Martian and NEOs are eternally going to be prohibitively expensive to mine
By using a form of "Propositional logic" Until we break free of the rocket community no advance in space travel is possible as you all point out are currant tech is prohibitively expensive which by definition, which is rocket propellant you have agreed the use of rocket propellant is a barrier to space travel

Jun 24, 2018
"... there is very little use for dirt in space."

Enough of it keeps the bubbles and ice rising in your soda.

Seriously, though, a big lump of the stuff makes for an effective 'solar storm shelter'. Remember how all those lovely plans for prettily-domed surface bases on the Moon had to go 'troglodyte' after the solar flare between the Apollo missions ? Had it caught a crew in transit or on the Moon, they'd be dead...

IIRC, shipping a back-hoe to the Moon is still a head-scratcher...

Jun 24, 2018
I see the discomfort with my meticulous approach. I should be making wild promises of instant success just like in the comicbooks.

I guess none of you ever dug a trench or laid brick. How to you dig a trench? First know where the hell it is needed. Then one shovel at a time.

How do you lay brick? First you have the location surveyed and a diagram of the structure you want. Then you pick up a brick and then lay it down. One damn brick at a time.

No magic wands or superpowers required. No matter how much your back aches afterward.

As for how you process NEOs? All that slag and debris you sneer at? Not only can shield a habitat. Also makes a nifty Bronze-Age smelter. Small, crude, persistent, methodical. Just like climbing a mountain or hardsuit diving to weld a pipe.

otto. I'm still hoping for a peek at your super-secret map locating ores on the Moon.

And just to satisfy my curiosity. How did you ever get your burro into a spacesuit? More than once?

Jun 24, 2018
Seriously, though, a big lump of the stuff makes for an effective 'solar storm shelter'. Remember how all those lovely plans for prettily-domed surface bases on the Moon had to go 'troglodyte' after the solar flare between the Apollo missions ? Had it caught a crew in transit or on the Moon, they'd be dead...
Musk's vessel will have a storm shelter. And we will be tunneling under the regolith on the moon and mars, living in shopping malls, condos, and game preserves.

If natural voids dont exist we can create them quickly and cleanly
https://en.wikipe...ct_Gnome

-using the miracle of nuclear fission.

Jun 24, 2018
I guess none of you ever dug a trench or laid brick. How to you dig a trench? First know where the hell it is needed. Then one shovel at a time
Willis wants to gather his bricks, one at a time, from all over the county... on his hands and knees.
otto. I'm still hoping for a peek at your super-secret map locating ores on the Moon
Seriously? Dozens on the internet like this
http://archives.a...0710.cfm
Also makes a nifty Bronze-Age smelter
Ah. So that's what you want all that carbon for. Briquettes.

Smelting is far easier with gravity.

Jun 24, 2018
Your maps, otto. interesting suppositions. Lots of 'suggesting' that perhaps there maybe deposits of economically viable deposits of accessible ore. Somewhere in a few hundred thousand hectares of where you landed your smelter & are tunneling like sunburnt naked molerats.

Walk into any bar in Anchorage or Carson City or Texarkana. For a couple of pitchers of beer & a couple of sawbucks get offered more precise & exact maps of where to find the motherlode.

For another pitcher of beer they'll throw in gratis about when they were picked up by a flying saucer & anally probed with a nightstick by a demented alien disguised as a County Sheriff's Deputy.

So yah wanna fly an industrial complex up out of the Earth's gravity well? Hauling it a quarter million miles. Dropping it into the Moon's gravity well. You did remember to bring an adequate supply of toilet paper & adult diapers? You realize the cost launching TP, it might be cheaper to use hundred dollar bills?

Jun 25, 2018
There is an asteroid just made for mining. Apophis will pass just under 20,000 miles from Earth on April 13, 2029. That's less than 1/10 the distance to the moon, and inside the orbit of most communications and weather satellites. (Some will have to be moved to avoid Apophis, and some will need orbital corrections after it passes. Of course, it is a wonderful opportunity to put as many dead satellites in Apophis' path as possible. Or if the proposals being discuss here happen, a manufacturing plant using dead geosynchronous satellites could use it to dump scrap.

I personally think that putting a robot miner on Apophis would be a great idea. Its orbit will be significantly changed by the 2029 passage, so that it regularly returns close to Earth.

Jun 25, 2018
99942 Apophis would actually be one of the most interesting asteroids in NEO for exploration.

Being an annual and it seems to be a stony conglomerate. Several different expeditions are at the talking stage,

The advantage I see is that it may turn out to be a cornucopia of many different minerals, some assorted metals and even perhaps some ices buried underneath the surface?

Whenever aeon it assembled out of the planetesmal debris? Could provide some insightful data for that time period.

Jun 27, 2018
Today an article in phys.org informs us, that the space probe Hayabusa2 has reached it's target the Ryugu asteroid.

https://phys.org/...ife.html

So far Ryugu seems to be a stoney amalgamate, similar to 99942 Apophis. What is learned over the next couple of years from this present mission should influence the objectives for research projects to be scheduled for Apophis .

Eventually, oover a couple of decades, it will be very interesting to compare the compositions and structures of Ryugu, Apophis and Didymos. To discover the similarities as well as the differences. And see if it can be determined if these three were produced by separate events? Or got violently knapped off a bigger rock? Or just slowly conglomed out of swarms of gravel and dust over billions of years?

https://phys.org/...ary.html

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