# Yn Dowan

| Yn Dowan  |
| --- |
|  |
| Sorçh | planaid sthie, soiaghey çheeroaylleeagh , as ard çheer-oaylleeagh |
| Date feddyn magh | veih'n çhenndaght |
| Epennym | **Y Dowan**: veih *\*dubnos* ("y diunid, dowin, y dowan") y Phroto-Cheltish **Y Chruinney**: veih *\*krundis* ("cruinn") y Phroto-Cheltish **Y Seihll**: Veih *saegul* ("seihll, bioys, y dowan") y Çhenn-Yernish, veih *saeculum* ("bea, eash, traa, y dowan") y Ladjyn |
| Moir-red | y Ghrian |
| Red lhiennoo | Yn Eayst |
| Amm | J2000.0  |
| Croo | 4.54 billoon bleeantyn er-dy-henney |
| Fysserree ishigagh |
| Sorçh fishigagh | cruinlagh grian-laarnagh |
| Apoapsis | 151,930,000 km ↔ y Ghrian 1 AU 1.01671 AU  |
| Periapsis | 147,095,000 km ↔ y Ghrian (arg (ω): 114.20783)  |
| Essylys lieh-vooar *a* | 1 AU , as 149,598,023 km |
| Corrid *e* | 0.016710219 |
| Amm cruinlagh *P* | 365.256363004 d |
| Mean-amreiltagh *M* | 358.617 °  |
| Cleayn *i* | 7.155 ° ↔ mean-chiarkyl ny Greiney 1.57869 ° ↔ mean-chiarkyl neuchaghlaaee |
| Foddid y noad ardjeeagh *Ω* | 348.73936 ° |
| Troghyn fishigagh as rollageagh meadragh |
| Foddeeaght veih'n Dowan | 0 km  |
| Craue raadeeoil | mean-chiarkyl: 6,378.137 km mean: 6,371 km poull çheer-oaylleeagh: 6,356.8 km  |
| Crantessen | 12,742 km  |
| Lheanaghey | 0.0033528  |
| Eaghtyr y vaare | 510,064,472 km²  |
| Glout | 5,972.37 Yg  |
| Thummid | 1,083,210,000,000 km³  |
| Mean-ghlooaght | 5.513 g/cm³  |
| Amm çhyndaaee | 24 h 86,164.098903691 s  |
| Ym-hayrn eaghtyragh | 9.798 m/s²  |
| Albedo | 0.434 (albedo towse-oaylleeagh) 0.294 (albedo Bond)  |
| Çhiassid eaghtyragh |

|  |
| --- |
|  |
| 15 °C  |

 |
| Aeraght |
Co-heiy
* 78.08% neetragien
* 20.95% ocsygien
* ~ 1% gaal ushtey
* 0.9340% argon
* 0.0413% daa-ocseed charboan
* 0.00182% neion
* 0.00052% hailium
* 0.00019% meetane
* 0.00011% krypton
* 0.00006% hiddragien
 |
| Ayrn jeh | corys y Dowan as yn Eayst , as Corys ny Greiney  |
| Catalogyn rollageydagh |
| 806.4616.0110 (Encyclopedia Galactica)  |

She **yn Dowan** ny **yn Chruinney** (lesh y daa chowrey  as ) y trass planaid veih'n Ghrian as yn ynrican red rollageydagh er fys ain ta cur aaght da bea. Ta e staydys myr seihll faarkee, yn ynrican seihll ayns Corys ny Greiney as ushtey ushlagh er, cur rish yn aaght yn-vaghagh shen. Ta begnagh y slane chooid jeh ushtey yn Dowan cummal 'sy cheayn dowanagh ayn, keayn ta coodaghey 70.8% jeh bleayst y Dowan. Ta'n 29.2% elley jeh bleayst y Dowan jeant ass thalloo ayns cummey mooar-hallooyn mooarheeragh çheusthie jeh lieh-chruinney thallooin y Dowan. ta'n chooid smoo jeh thalloo yn Dowan red beg tash as coodit lesh glasseraght, choud's ta ny coodaghyn-rioee ec faasaghyn poullagh y Dowan freayl ny smoo ushtey na'n slane ushtey t'ayns ushtey thallooin, loghyn, awinyn, as aeraght y Dowan currit ry-cheilley. Ta bleayst y Dowan jeant seose jeh plaityn tectonagh ta gleashagh dy moal as ta geddyr-obbraghey rish y cheilley dy chroo slieau-reaynyn, volcaanyn, as craaghyn thallooin. Ta cree mooie ushlagh ec y Dowan as t'eh gientyn magnaidsfeyr ta castey yn chooid smoo jeh ny geayaghyn greiney as y ghoulraght huinnagh stroialtagh.

S'gleashagh yn aeraght t'ec y Dowan, ta cummal as gymmyrkey foaynooyn eaghtyragh y Dowan as freayl eh veih'n chooid smoo jeh dreigee as jeh'n tollysh erskyn-ghorrym ec y voayl-entreilys. Er y chooid smoo, t'eh jeant ass neetragien as ocsygien. Ta'n gaal ushtey feer heelaghtagh ayns aeraght y Dowan ta croo bodjallyn ta coodaghey yn chooid smoo jeh'n phlanaid. Ta'n gaal ushtey shoh gobbraghey myr gas thie-glionney as, currit ry-cheiley rish gassyn thie-glionney elley 'syn aeraght, y daa-ocseed charboan (CO2) er lheh, croo ny foaynooyn femoil da mayrnaght yn ushtey ushlagh eaghtyragh as y ghaal ushtey hene lesh goaill bree veih sollysh ny Greiney. Ta'n obbraghey shen freayl y çhiassid veanagh roie er 14.76 °C (58.57 °F), raad ta'n ushtey tannaghtyn ayns cummey ushlagh fo broo aeraghtagh cadjin. Ta anchaslyssyn ayns mooad y vree t'er ny ghoaill eddyr ny h-ardjyn çheer-oaylleeagh (myr sampleyr, ta ny h-ardjyn meanchiarkylagh geddyn ny smoo sollysh greiney na ny h-ardjyn poullagh) cur rish kiarkley aeraghtagh as strooyn keayin, reddyn ta gientyn corys emshyraght as ardjyn emshyraght eigsoylagh as straih dy phenomenonyn emshir lheid as frassaghey as eh lhiggey da co-oltyn lheid as çhymshallyn carboan as neetragien.

Yn Dowan myr t'eh ry-akin veih eaghtyr yn Eayst
Ta'n Dowan runtit myr eelipsoyd mysh 40,000 km (24,900 mi) er ym-linney. T'eh ny phlanaid smoo gloo ayns Corys ny Greiney. Mastey ny kiare planaid ooiragh, she yn Dowan y fer smoo rere mooady as glout. T'eh soit mysh hoght sollys-vinnid (1 AU) magh veih'n Ghrian er y vel eh cruinlaghey ayns un vlein dy hyndaa (mysh 365.25 laa). T'n Dowan çhynda er e essyl hene ayns tammylt beggan ny sloo na un laa (mysh 23 oor as 56 minnid). Ta essylys çhyndaaee yn Dowan cleaynit rish y jeeraghan da'n phlaaney cruinlee echey mygeayrt y Ghrian, red ta cur rish crooaght imbaghyn. Ta un fo-phlanaid beayn cruinlaghey yn Dowan — yn Eayst — as t'eh cruinlaghey yn Dowan mysh 384,400 km (238,855 mi) — 1.28 sollys-hootçhey — voish. Ta'n Eayst cho mooar as un chierroo yn Dowan er lheead as ta'n ym-hayrn echey cur cooney rish co-soiaghey essylys y Dowan, red ta jannoo tideyn as ta moaldey çhyndaays y Dowan beggan er veggan. Er y laue elley, ta ym-hayrn y Dowan er ny yannoo çhyndaays yn Eayst kianglt rish y Dowan dy tidee, as, kyndagh rish shen, ta'n Eayst dy beayn taishbyney yn un eddin dooin.

Gollrish y chooid smoo jeh ny corpaneyn ayns Corys ny Greiney, va'n Dowan er ny chroo mysh 4.5 billoon dy vleeantyn er-dy-henney veih gassyn as joan ayns Corys ny Greiney leah. Va'n keayn er ny chroo car y chied villoon dy vleeantyn ayns shennaghys y Dowan as, eisht, hie yn bea er ny lhiassaghey çheusthie jeh. Hi yn vea er ny skeaylley magh feie ny cruinney ny yei as eh ceaghley aeraght as eaghtyr y Dowan veih shen, red chur rish y Taghyrt Ocsaidaghey Mooar daa villoon dy vleeantyn er-dy-henney. Dirree as daase deiney 300,000 bleeaney er-dy-henney 'syn Affrick as t'ad er ny skeaylley magh dys dagh mooar-rheynn er y Dowan. Ta deiney croghey er beasfeyr as cooid najooragh y Dowan, agh t'ad er ny yannoo jeeill da çhymmyltaght y phlanaid. Cha nel builley roie ny deiney er e emshyraght as as e veasfeyr yn-chummalagh, as t'eh baggyrt er beaghey deiney as cummaghyn elley dy vea, as cur rish anvioyssyn lheeadagh.

## Imraaghyn