Saur Mandal

Saur mandal (Solar system) me me Suraj aur uu grah hae jon ki iske gravity se bandha hae aur iske round jaawe hae. Suraj ke parikrama kare waala grah (planets), asteroids, comets aur duusra chij bhi hae. Saur mandal lagbhag 4.568 billion saal puraana hae. Suraj ek barraa molecular cloud me gravity se banaa hae. Ii jaada kar ke hydrogen hae, jon  nuclear fusion se helium ban jaawe hae. Grah, ek flattened parkramaa kare waala disk me hae. Ii disk uu bachaa cloud se banaa hae jon ki surak ke bane ke time bach gais rahaa. Baad me disk ke gardaa aur gas saathe aae ke grah ban gais. 

Suraj ek taara hae aur saur mandal ke 99.9% wajan isme hae. Iske matlab hae ki suraj ke graviry kaafi tagrraa hae aur iske kaaran aur sab grah ke ii khiich ke aapan aound ornit me kar liis hae. Saur mandal me aath grah hae:Budhgrah (Mercury), Sukhrgrah (Venus), Dunia (Earth), Mangalgrah (Mars), Brahaspati (Jupiter), Sanigrah (Saturn), Arungrah (Uranus) aur Varungrah (Neptune). Pahila chaar grah patthar aur dhaatu (metal) se banaa hae aur baaki chaar grah gas se banaa hae. 

Chhe grah aur chhe sab se barraa "dwarf planet" ke chandarma parkramaa kare hae. Saur mandal me 200 se jaada chandarma hae. Mercury aur Venus ke koi chandarma nai hae. Jupiter aur Saturn ke lage sab se jaada chandarma hae. Jupita ke chandarma, Gandymede sab se barraa chandarma hae. Saturn ke ek chandarma, Titan khaali ek chaand hae jiske atmosphere hae, jon ki nitrogen hae. 

Mars aur Jupiter ke biich me asteroid belt hae. Neptune se duur KUiper belt aur "scattered disc" hae. Isme dwarf  planet hae, jaise ki Pluto, Makemake, Haumea,  Ceres aur eris. Ii jagha pe dher dher chhota chij, comet, centaur aur dust hae.

vibhag:S
Category:Taara vigyan