The Bridge V Learning Edition 1 ; our solar system | Page 47

Tactile features: ( wh il e you ex plo re the ta ct ile s che ma t ic ima ge) Mountains and Maria The vis ible su rfac e of th e Moo n sh ows bright and d ark a rea s . Th e bright area s a re ge ne ral l y h il ls o r moun ta ins (mate rial ize d by th ick fa bric o n th e ta ct ile ima ge) , wh il e the da rk o nes are fl at la nds , c al le d “ma re ” ( ma te rial ized by th in f abric in re l ie f on the tac t il e ima ge ). The se low al t itud e a rea s we re f ill ed with la va du ring a n anc ie nt p e riod of vo lc an ic ac t ivit y, a rou nd 3 bill ion ye a rs a go . Mo st of the m we re na me d b y an c ie nt as t rono me rs a fte r commo n ph enomena e ncou nt e red on t e rres t ria l s eas a nd oc ea ns : Oc ea nus P roc ell a ru m ( ‘Oc ea n of S to rms ’) , Ma re I mbriu m ( ‘S ea of Ra ins ’), M a re S e re nit at is (‘S ea o f Se renit y’), Ma re Tranqu il ita t is ( ‘S ea of Tran qu il it y’) , e tc . Craters The whol e f ace of th e Moo n is dot ted with cra te rs, with d ia met e rs f ro m a fe w met e rs t o hu n d red s of k ilo me t re s (cu rve d se qu ins) . The y a re th e re sul t of imp act s by as te ro ids , s ince the Moo n doe s not h ave a ny a tmosph e re to p re vent th em f ro m re ach ing th e su rf ac e (a fe w of the m a re mate rial ize d by but to ns on the ta ct ile ima ge: Pl ato an d A ris to te les at the t op , A rist a rchu s on the lef t , Cop e rnicus ne a r th e c ent re , a nd C la vius at the bot tom). Co pernicus h as a d iamete r of 93 km and is l oc ate d in M a re I mb riu m at the end of a ch ain of mou nta ins ca ll ed A pe nnins ( ma te ria l ized b y th e th ic k f ab ric o n to p of t he th in fa bric o n th e ta ct ile ima ge) .