Circles in the sand

Adragonstirsdeepbeneathadesert.Itslithersthroughthesandydirt,breathingafiery,poisonousgasasitmoves.Thegasbubblesuptothesurface.There,itburnscirclesofbaredirtinthe grass.


Orsothestorygoes.Noonehasseenthismythicalbeast.Yet,somepeopleinsouthernAfricasayit’sthere.It’showtheyexplainthemysteriouscirclesthatappearontheeasternedgeoftheNamib Desert.


Thousandsofcirclesstretchasfarastheeyecansee.Somearesmall,justonemeter(threefeet)wide.Othersareaswideas50meters(164feet).Itwouldseemthatthedragonhasbeen busy.

Searching
foraCause

Noteveryonebelievesindragons.So,scientistshavelookedforothercausesforthe circles.


Somethinkthat,likethemythicaldragon’sfierybreath,agasbubblesup.Othersthinkthatantsmaychewtherootsofthegrasses.Stillothersthinkthattoxicplantsmayspreadtheirpoisons.Anyoftheseactionscouldhavethesameeffect.Theycouldkillthe grasses.


Thesearealltheories,orideas.Theyseempossible.Yet,scientistshavetoproveatheorybeforeit’sacceptedas fact.

Mysteriouscirclesstretchasfarastheeyecan see.

Mysteriouscirclesofbaredirtdotthisdesertonthewestcoastofsouthern Africa.

Africa

NamibDesert

NorbertJuergensandhiswife,Irmel,collectweatherdataneara circle.

DesertDiscoveries

Onescientistthinkshemayhavesolvedthismystery.BiologistNorbertJuergenshasvisitedthisdesert40times.He’sstudied1,200circles,lookingforevidenceofwhatcausedthem.He’slookedforpatternsamongthecircles,tryingtodiscoverwhattheyhavein common.


Thebiologistsiftedthroughthedirtinsidethecircles.Hetestedthedirtforchemicalsandmeasuredhowmuchwaterwasinit.Herecordedtheanimalshesawinthecircles.Hewrotedownthenamesofplantsgrowingnearby.Hetrackedchangesin
the weather.


ThenJuergensstudiedallhisdata.Hefoundsomedifferencesbetweenthecircles.Coloniesofantscrawlthroughsome.Spidersspinwebsinthegrassesgrowingaroundothers.Aardvarksevenvisitsome circles.

CommonClues

Juergensdidn’tjustfinddifferencesamongthecircles.Healsofound similarities.


Eachcirclehaddry,sandysoilinitscenter.Healsofoundsomethingsurprising.Eveninthedryseasonwhenitbarelyrains,thegrassesaroundthecirclesstayedalive.Tofindoutwhy,hedugdeepintothesoil.Hediscoveredwetsandundereachcircle.Thegrassrootstappedintothewatertokeepthegrasses alive.


Juergensalsofoundsomethingelseineverycircle.Hefoundsandtermites.Thesetermitestunnelthroughdirt.Theychewonplant roots.


Juergensstudiedthesecommonclues.Helookedforwaystheycouldconnect.Thenhecameupwithhisown theory.

sand termites

MysterySolved?

Juergensthinksthattermiteseatsomegrass roots.Thatkillsthegrassgrowingabovetherootsandformsacircleof
bare dirt.
 


Whenitrains,watersoaksintothedirt.It’ssavedinapoolunderthedirt.Thetermitesdrinkthiswater.Thegrassesaroundthecirclesoakitup.It’showtheseinsectsandplantssurviveinthedesertduringthedry season.

Juergenswillhavetostudymorecirclestoproveifhis theoryiscorrect.Yet,hemaybeonestepclosertosolvingthemysteryofthecirclesinthesand.Thetermitesaren’tfire-breathingdragons.Still,they’reprettyremarkable.Thesetinyinsectsmayhavecreatedoneofnature’sstrangest mysteries.

Aviewfromaboveshows circularpatchesdottingthelandintheNamib Desert.