riya (upagrah)

kaiseeni antariksh yaan dvaara li gayi riya ki tasveer
pruthvi (daaeain), hamaare chandrama (oopar baaeain) aur riya (neeche baaeain) ke aakaaron ki tulana

riya hamaare saur mandal ke chhathe grah shani ka doosra sab se bada upagrah hai. riya saur mandal ke saare upagrahon mein se nauva sab se bada upagrah hai. iski khoj 1672 mein Italy ke khagolashaastri jiovaanni kaiseeni ne ki thi. riya ke ghanatv ko dekhte hue vaigyaaniko ka anumaan hai ke yeh 25% patthar aur 75% paani ki barf ka bana hua hai. is upagrah ka taapamaan dhoop par nirbhar karta hai. jahaaain dhoop pad rahi ho vahaaain iska taapamaan -174 degree seinteegred (99 kailvin) hai aur jahaaain aaindhera ho vahaaain yeh girkar -220 degree seinteegred (53 kailvin) chala jaata hai. iski satah par antariksh se gire hue ulkaapindon ki vajah se bahut se gadhdhe hain, jinmein se do to bahut hi bade hain aur 400 se 500 kimi ka vyaas (daayaameetar) rakhate hain.

anukram

anya bhaashaaoain mein

riya ko angreji mein "Rhea" likha jaata hai. praacheen yoonaani dharm mein riya devataaon ki maata theen.

aakaar

riya ka vyaas (daayaameetar) lagbhag 1,528 kimi hai. tulana ke liye pruthvi ke chandrama ka vyaas lagbhag 3,470 kimi hai, yaani riya se dugana.

chhalle

3 March 2006 mein ameriki antariksh praadhikran (naasa) ne ghoshana ki ke unhein riya ke ird-gird kuchh kamzor se upagrahi chhallon ke astitv ke suraag mile hain. haalaanki abhi is baat ko pakka naheen kiya gaya hai, agar aisa paaya jaata hai to riya saur mandal ka pehla aisa upagrah hoga jiske ird-gird chhalle hain.

vaayumandal

27 November 2010 ko ameriki antariksh praadhikran (naasa) ne ghoshana ki ke riya par ek patala sa vaayumandal maujood hai, jismein okseejan aur kaarban daaioksaaid maujood hain.

inhein bhi dekhein

bahari kadiyaaain