back to article Aww, a cute mini-moon is orbiting Earth right now. But like all good things, it too will abandon us at some point

Earth has a mini-moon: a space rock close enough to be a near-Earth asteroid spotted this month orbiting our planet. The object, known as 2020 CD3, was reported by the International Astronomical Union’s Minor Planet Center, a small organisation that tracks asteroids and comets. It's most likely an asteroid that has been …

  1. Paratrooping Parrot

    Another question for QI

    You know all those questions on QI about how many moons does the earth have!

    1. KittenHuffer Silver badge
      Boffin

      Re: Another question for QI

      There's only one moon! The rest have been redefined as 'Dwarf' moons!

      1. W.S.Gosset Silver badge
        Childcatcher

        Re: Another question for QI

        That's a bit racist.

        They preferred to be called "little moons" back in the day. Now, they're "mass challenged".

        1. A K Stiles Silver badge
          Coat

          Re: Another question for QI

          Massively challenged ?

        2. Doctor Evil

          Re: Another question for QI

          Oh, even that is over the line! They're "differently massed"

          1. HildyJ Silver badge
            Pint

            Re: Another question for QI

            Massed still smacks of sizeism. Let's just say that they are nonconforming moons.

            1. W.S.Gosset Silver badge

              Re: Another question for QI

              LBGTI: Little Big Greencheese* Trans-uranian** Ireallydontcare

              * previously Gibbous (term now regarded as islamophobic)

              ** previously Tsuki-no-usagi (term now regarded as a slavery metaphor)

  2. Anonymous Coward
    Anonymous Coward

    Aliens!

    Or just another garbage pod...

    1. Chris G Silver badge

      Re: Aliens!

      Vogon survey drone, it won't be here for long.

      1. W.S.Gosset Silver badge

        Re: Vogon survey drone

        ^it^we

        Just in time for coupla pints and some crisps. (And change from a fiver!)

        1. I ain't Spartacus Gold badge
          Happy

          Re: Vogon survey drone

          I'd prefer peanuts to crisps.

          The salt and protein help to cushion your system from the matter transfer process you see...

          1. SonofRojBlake
            Coat

            Re: Vogon survey drone

            You lose salt and protein from the matter transference beam, which the peanuts replace. It's the beer that "cushions your system a bit"...

            (Mine's the one with the towel in the pocket)

      2. Stumpy
        Coat

        Re: Aliens!

        Oh freddled gruntbuggly,

        Thy micturations are to me, (with big yawning)

        As plurdled gabbleblotchits, in midsummer morning

        On a lurgid bee,

        That mordiously hath blurted out,

        Its earted jurtles, grumbling

        Into a rancid festering confectious organ squealer. [drowned out by moaning and screaming]

        Now the jurpling slayjid agrocrustles,

        Are slurping hagrilly up the axlegrurts,

        And living glupules frart and stipulate,

        Like jowling meated liverslime,

        Groop, I implore thee, my foonting turlingdromes,

        And hooptiously drangle me,

        With crinkly bindlewurdles,mashurbitries.

        Or else I shall rend thee in the gobberwarts with my blurglecruncheon,

        See if I don't!

        ... the one with the poetry book in the pocket please.

        1. Marcelo Rodrigues
          Trollface

          Re: Aliens!

          "... the one with the poetry book in the pocket please."

          Now, see what you've done? I just gnawed my two feet off!

  3. Marketing Hack Silver badge
    Alien

    So how long until this orbiting object destroys Washington DC with a death ray blast?

    (And can we pay it to do this sooner?)

    1. I ain't Spartacus Gold badge
      Black Helicopters

      Re: So how long until this orbiting object destroys Washington DC with a death ray blast?

      The Secret Service have noted this post and will be with you shortly. Please remain at your place of work or residence until our customer service team have arrived.

      Thank you for your cooperation.

      1. macjules Silver badge

        Re: So how long until this orbiting object destroys Washington DC with a death ray blast?

        Resistance is futile.

  4. Groove-Cat

    That's no moon....

    ;)

  5. Will Godfrey Silver badge
    Unhappy

    Poor little thing

    It's obviously lonely, and wants a bit of company. Trouble is that if big old earth just ignores it then it'll feel rejected and go away... feeling even more lonely.

  6. Annihilator Silver badge

    "Space rocks visiting Earth like this are rare. Described as mini-moons, the only other time that one graced our planet (that we know about) was in 2006. A tiny asteroid, measuring a couple of meters in diameter and known as 2006 RH120 was also discovered by folks working at the Catalina Sky Survey."

    Presumably it's ruddy hard to spot them though, particularly given they don't stay for long, so do we know how rare or not it is?

    1. Tom 7 Silver badge

      I did wonder about how they worked out what percentage of asteroids of certain sizes they'd found using the logic you use above.

      They scan the skies for asteroids and compare the number of new ones they've found with the number of old ones they found again!

      Given 2 is all we have found so far and they bugger off I think this may the wrong way to go about it but in a few hundred years we may get a useful data set.

  7. Alister Silver badge

    I know I could probably Google this, but just out of curiosity, once an asteroid is captured in Earth orbit, how does it manage to break free again?

    1. ibmalone Silver badge
    2. awoze

      It doesn't have a stable, circular orbit.

      It's going to do a few loops around our planet, then its expected path will take it too far out of Earths gravity well.

      Important to note that the Earths gravity isn't the only one in play.

      1. Anonymous Coward
        Anonymous Coward

        That's not quite how it works. If you are doing "loops" then you are orbiting and "stable". What is may mean is it's orbiting, but the changes of gravity caused by the Moon (for example) wissing past will then perturbed it back out of orbit. Presumably the moon helped in the original capture.

        AFAIK you'll only get one or two pass bys if a natural "capture" with a non stable orbit. Any real captures require something to slow it down (solar wind, perturbations in the planet, not likely at our size, or a moon/third body to disrupt the flyby).

        1. zuckzuckgo Bronze badge

          >"Any real captures require something to slow it down"

          How about a hastily put together SpaceX mission to give it a nudge? Considering the effort that goes into missions to study such objects, it would be nice to have one in a longer term stable - or at least somewhat predictable - local orbit for future science missions.

    3. Ali2007

      Not a very easy question to ask Google so I'll answer.

      The asteroid has an oval orbit, with an apogee (highest point in the oval orbit) beyond the lunar orbital distance. This means given enough time at some point it will come into the moon's sphere of gravitional influence and be slung back out into interplationary space

      1. David Hicklin

        "moon's sphere of gravitional influence and be slung back out into interplanetary space"

        But could it be slung the other way and come down on someone's head ?

        1. HelpfulJohn Bronze badge

          "But could it be slung the other way and come down on someone's head ?"

          Yes, technically it can. But ...

          The Earth is *tiny* and the rest of the universe is damned *huge* so hitting the tiny, tiny Earth is far more unlikely than hitting the rest of the universe or even the littly bit of it that our Sun looks after.

          True, millions of tons of dust, detritus, small rocks and bigger boulders *do* hit the Earth each and every year and every so often a quite large to bloody enormous one will find us but those things [apart from the QLTBE-types] do pretty much no harm at all.

          A small, car-sized brick won't do much, either even should it suddenly decide to cuddle up to our little planet. Odds are it would break up to provide a few fireballs and pretty falling "stars" that would be seen over some Russian village.

          They are *always* seen over Russia, which is probably all to the good.

    4. KittenHuffer Silver badge
      Boffin

      Science Alert!

      Technically there is no such thing as a stable orbit even for just two bodies, when considered on long enough timescales.

      Two objects (spherical and in a vacuum) orbiting each other will radiate energy as gravity waves. This will cause the orbits to shrink, and eventually the two objects will be one.

      It's just that for small objects (e.g. the Sun and the Earth) the timescale required to radiate this amount of orbital energy is long enough that the life cycle of the objects happens first (Sun -> red giant -> planetary nova)!

      And yes, the Moon is slowly moving away from the Earth. But that’s because it’s stealing rotational energy from the Earth by the use of tides.

      1. STOP_FORTH Silver badge
        Alien

        Re: Science Alert!

        That's a bit judgemental, standard anti-Selenian bias.

        How do you know it's not Fifth Column ocean water traitorously giving it away?

      2. MJB7 Silver badge
        Pint

        Re: Science Alert!

        Only an astronomer could call the Sun a "small object" with a straight face.

        Icon: because I've been saying that astronomy is an excellent excuse for a party for 40 years.

        1. Claptrap314 Silver badge

          Re: Science Alert!

          And no quirk in his voice.

      3. HelpfulJohn Bronze badge

        Re: Science Alert!

        "And yes, the Moon is slowly moving away from the Earth. "

        Well, the Moon isn't one, she's more of a companion planet or, considering the I.A.U.'s recent unfair demotion of Pluto and the asinine "reasoning" behind that, a companion Dwarf Planet. Luna, the Moon, isn't "round", she's more ovoid [allegedly due to the gravity of a nearby object] and she sort of, kind of, slightly hasn't exactly totally cleared her orbit of large lumps. We now that latter because we live on one of the uncleared bits - well, many of us do, some of the time.

        As Luna, the Moon, isn't "really" a moon, one should not expect her to behave as the other, littler [compared to their hosts] ones do.

        Of course, the Earth is a slightly lumpy oblate near-spheroid that hasn't cleared her orbit [see the article for details] so the Earth isn't a planet, either. It's debatable that any object save Venus [maybe Mercury, too] *is* a planet.

    5. Alister Silver badge

      Thanks for all the replies, I thought it would be something to do with an unstable orbit.

    6. Version 1.0 Silver badge

      Checkout the Voyager 2 path and you'll see how this works - it's like running down a steep hill with trees, just grab one and swing around to the next one and then head downhill to the next one.

  8. Conundrum1885 Bronze badge

    You sure its just a rock?

    Incidentally a "Free return trajectory" might arouse very few suspicions.

    Its been suggested that a Bracewell Probe might use this method.

    Mine's the one with "Hyperspace" M Kaku in the pocket.

  9. RegW

    Dude where's my ...

    1. adrianww
      Alien

      ...continuum transfunctioner?

  10. Pete4000uk

    Wouldn't it be great

    If we did permanently captured somthing. Lots of local science to be done.

    1. John Robson Silver badge

      Re: Wouldn't it be great

      Given a little bit of lead time we could do local science even with a temporarily captured object.

      We have probes designed for asteroid encounters in deep space... I'm sure we have a spare one (it would have to be old enough that the primary mission of the version in space has finished) that we could pop onto a rocket and set up an intercept.

      1. Anonymous Coward
        Anonymous Coward

        Re: Wouldn't it be great

        If this is the second one in less than twenty years perhaps we could prepare for the next one.

      2. Citizen99
        Angel

        Re: Wouldn't it be great

        Now, what happened to the Giotto Engineering Model ?

      3. HelpfulJohn Bronze badge

        Re: Wouldn't it be great

        Does the Ceres-Vesta "Dawn" probe have a museum-quality twin sitting around spare? Could we power her up, plonk her on a rocket and zap her to this new moon of ours?

        Hell, I'd volunteer to go on a Soyuz or ESA re-supply rocket without a return ticket, just for the "wheeeee" of it. I'm sure I can be remotely piloted by real geologists, chemists and other actual Scientists so I could do valuable work.

        Anyone at NASA, ESA, JAXA or the Indian one reading this?

    2. Chris G Silver badge

      Re: Wouldn't it be great

      I think some dinosaurs captured one a while back.

      Didn't end well.

      1. Jim Mitchell
        Mushroom

        Re: Wouldn't it be great

        Would have been OK, but they muffed the parking.

  11. xyz

    Hold on a mo...

    This thing has been parked up for 3 years and nobody noticed a 3m (approx) wide POS wafting about. I thought NASA was constantly tracking everything bigger than a small shit. And you would've thought Donald's Space Farce would have given it a poke. Obviously everyone has been in "don't mention aliens" mode up to now.

    1. Doctor Syntax Silver badge

      Re: Hold on a mo...

      "This thing has been parked up for 3 years and nobody noticed"

      Don't you believe it. The (non Register) vultures who run the local B & Q car park have been ticketing it. The fines are going to be horrendous.

    2. JCitizen
      Devil

      Re: Hold on a mo...

      How do you know the old "Orange One" didn't decide to strap a TLA onto the thing to bomb Iran? That would be a handy excuse to say, "we didn't do it - Allah did!" Hee! Hee! Hee!

      It is the perfect excuse - especially since they already worship a space rock every Hajj at Mecca, how could they lose! Hee! Hee! Hee!

      1. JCitizen
        Unhappy

        Re: Hold on a mo...

        Never mind, it would never survive the earths atmosphere upon entry. Oh well - it was a wonderful scheme!

        1. HelpfulJohn Bronze badge

          Re: Hold on a mo...

          As the post above stated, they *do* worship a rock that *did* survive entry [ *NOT* "re-entry" as it probably didn't start its life as a part of Earth] so it's possible this one might.

          It depends on what it's made of and how we land it. Dropping it vertically, like a rock, would be best as this would give it least time to interact destructively with the airs of Earth and most opportunity to merge interactively with the less squishy bit. It wouldn't do much regional damage even so but it might damage the core of a city if it fell from its apogee.

          The problem with that is The Rocket Equation. It takes effort to cancel orbital motions, as much effort as it takes to set them up and even a little rock weighs many tons. Effort means fuel and fuel must be lifted from Earth's surface to the moon.

          Sending in the U.S. Armed Forces is probably cheaper.

  12. Rich 11 Silver badge
    Alien

    Watch the skies!

    The mini moon stuck around for less than nine months until it flew off back out into space.

    Just long enough for its passengers to awaken, spawn and send down the hatchlings.

    1. Will Godfrey Silver badge
      Facepalm

      Re: Watch the skies!

      The Ramans always do things in threes

  13. SVV Silver badge

    the object, known as 2020 CD3

    Wow, they're now naming moons after pisspoor backup strategies!

    1. John Brown (no body) Silver badge
      Coffee/keyboard

      Re: the object, known as 2020 CD3

      Git!! See icon ------------>

  14. Anonymous Coward
    Anonymous Coward

    I idly wonder about the challenge of landing this on earth ?

    Without burning it up ? The ability to be able to do so would certainly be another step on our aspirations to explore where we can.

    I wonder if there's any commercially viable minerals we could pull from it ?

    1. Anonymous Coward
      Anonymous Coward

      Re: I idly wonder about the challenge of landing this on earth ?

      Please visit my crowd funding page to donate to this essential piece of science.

    2. Annihilator Silver badge

      Re: I idly wonder about the challenge of landing this on earth ?

      "Commercially viable minerals" is probably the wrong one to measure.

      Let's assume it's 3m in diameter and roughly spherical. This would make it 14.14m^3. Let's pretend it's made of pure platinum. This would make it around 300 tonnes of the stuff apparently. Worth of that is around $9bn. Average cost of a space shuttle mission was around $1.5bn.

      I guess the problems with this are:

      * It's orbiting way higher than the shuttle's range

      * The shuttle or anything like it doesn't exist anymore

      * It's almost certainly made of a less valuable material than platinum :D

      1. Anonymous Coward
        Anonymous Coward

        Re: I idly wonder about the challenge of landing this on earth ?

        Thanks for engaging in a serious discussion. Commentards are known to swing both ways :)

        1. Annihilator Silver badge
          Thumb Up

          Re: I idly wonder about the challenge of landing this on earth ?

          There’s nothing I take more seriously than imaginary platinum space mining.

      2. Doctor Syntax Silver badge

        Re: I idly wonder about the challenge of landing this on earth ?

        * Dumping 300 toms of platinum on the market would probably lower the price.

        1. ibmalone Silver badge

          Re: I idly wonder about the challenge of landing this on earth ?

          Particularly if dumped from orbit.

          1. The Nazz Silver badge

            Re: I idly wonder about the challenge of landing this on earth ?

            Yeah but think of the value of the "bidding rights" from cities, ie the modern trend to waste millions bidding for an event, to be the one it is dropped upon from orbit.

            Halifax : "We'll bid 1.2bn to drop it in Bradford."

            Leeds : "We'll bid 2.3 bn if you drop it on Bradford."

            Kirklees* : "We'll bid 14.3 bn if you drop it on us."

            Sold, to the highest bidder.

            *Not technically a city but ne'er mind.

            1. HelpfulJohn Bronze badge

              Re: I idly wonder about the challenge of landing this on earth ?

              ........

              Bradford City Council [in Exile]: We'll bid 34 billion if you drop it on Bradford.

          2. HelpfulJohn Bronze badge

            Re: I idly wonder about the challenge of landing this on earth ?

            Hmm, that may depend on *where* one dumped it.

        2. Annihilator Silver badge

          Re: I idly wonder about the challenge of landing this on earth ?

          I considered that, but as part of my “research” (loose sense of the word) I discovered we mine almost 200 tonnes of platinum a year, so probably not as big an adjustment as you might think. I was particularly surprised by that.

          I suppose the other thing to consider is the cost of mining that on earth as a comparison to a shuttle-esque mission. Hard to put a number on it, but some stories suggest platinum mining is barely breaking even at the moment, so maybe the space shuttle to the non-existant platinum moon might be worth considering.

      3. Anonymous Coward
        Anonymous Coward

        Re: I idly wonder about the challenge of landing this on earth ?

        Plus, if you were to introduce 300 tonnes of platnum to the Earth market, it might not be worth S9bn anymore. The Reg had an article on asteroid mining economics a while back that did the math.

        1. JCitizen
          FAIL

          Re: I idly wonder about the challenge of landing this on earth ?

          You'd have to mine it from space, because it would never survive the atmospheric entry. Oh well!

          1. Annihilator Silver badge

            Re: I idly wonder about the challenge of landing this on earth ?

            "You'd have to mine it from space, because it would never survive the atmospheric entry. Oh well!"

            The whole point of this exercise is to use the space shuttle or similar. It's cargo bay was plenty big enough to hold the platinum moon (the moon is only 3m in diameter), but you're right it may well be a bit of a strain on the landing gear.

  15. RegGuy1 Silver badge

    Brexit

    So something else that will Brexit soon.

    (Brexit -- big rock exit; as in big rock = mini moon; Mmexit didn't work!)

  16. Ramis101

    Are you sure its not just Grit on the Scanner Scope?

    Oh yea, that's black holes

  17. Chris 15
    Alien

    In the near future? a question

    By this I take it you mean as soon as the orbit of this rock reaches the other end of what must be a hyperbolic orbit since it is going to escape the influence of our bigger rock.

    One question I have is this, how does a mass in interplanetary space (or interstellar for that matter) get permanenty captured (ie enter a non hyperbolic orbit)? Since there is no friction in space other than if hitting some kind of atmosphere or the bigger mass that has captured the smaller one wouldn't this leave the 2 options of either joining the mass of the larger object permanently or being flung out on a hyperbolic orbit for somerthing like 99.999999% of the time?

    1. Claptrap314 Silver badge

      Re: In the near future? a question

      It take three to do the capture tango.

    2. JCitizen
      Go

      Re: In the near future? a question

      It is all in the orbital maths - if it doesn't add up - it won't happen.

    3. HelpfulJohn Bronze badge

      Re: In the near future? a question

      "... how does a mass in interplanetary space (or interstellar for that matter) get permanenty captured ..."

      Jupiter's moon, Io has one answer to that.

      Tidal heating and momentum swapping during the flyby. Sort of like what is causing the Moon to fall upwards, away from the Earth but in reverse mode. Angular momentum can be transferred into or from the primary object's rotation, kinetic energy converted into heat.

      It would take a large number of close approaches to drain the momentum and angular momentum from a passing rock but the physics isn't magic. The result may be magical and full of wonderment but the process is just the cosmos doing its thing.

      Like a rainbow.

  18. TechnicalBen Silver badge
    Thumb Up

    "Travelling in an oval shaped orbit."

    Ah. Interesting. So it's not in a "horseshoe" type orbit. It's a proper temp straggler in a stable (ish?) orbit. :P

    1. Claptrap314 Silver badge

      Re: "Travelling in an oval shaped orbit."

      Until it gets too close to the moon...

  19. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921 Bronze badge

    It's a Kling-on from Uranus

    1. Citizen99

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