#51 helios – Greek – sun heliotrope (tropos – turn) – plant which turns toward sun helioscope (skopeo – look) – telescope for looking at the sun heliometer (metron – measure) – instrument for measuring the diameter of the sun

#52 sol – Latin – sun solar – pertaining to the sun parasol (Italian – parare – to ward off) – a light portable sunshade (like an umbrella) solstice (sisto, statum – set, cause to stand) – standing still of the sun *summer solstice – June 22nd, longest day *winter solstice – December 22nd, shortest day

#53 luna – Latin – moon lunacy – madness caused by the moon; “moonstruck” lunambulist (ambulo, ambulatum – walk) – one whose sleepwalking is supposedly caused by the moon lunation – 29 ½ days – a lunar month or the time from one new moon to the next

#54 dia – Greek – through, between, across, apart diagonal (gony – knee) – line between 2 non-adjacent corners in a figure of 4 or more sides diagram (graph – write) – a cross-section drawing diagnosis (gnosis – knowledge) - thorough knowledge

#55 trans – Latin – across, over, beyond, through transaction (ago, actum – do, drive) – trade, exchange transform (formo, foratum – form, shape) – change to a different form transparent (pareo – appear) – to be seen through

#56 geo – Greek – earth geography (graph – draw) – draw the earth (make maps) geology (logos – word, study) – study of the earth and its formations geometry (metron – measure) – branch of study on ways to measure the earth

#57 terra – Latin – land territory – land under control of a government or owner terra cotta (coquo, coctum – cook) – “cooked earth”, fired clay pottery, tiles, etc. extraterrestrial (extra – outside) – outside the earth’s atmosphere

#58 dormio – Latin – sleep dormant – sleeping dormitory– place for sleeping dormitive – something that causes sleep

#59 hypnos – Greek – sleep hypnotize – put into a hypnotic sleep or trance hypnology (logos – word, study) – study of sleep hypnophobia (phobos – fear) – fear of sleep

#60 annus – Latin – year anniversary (verto, versum – turn) – celebration marking the turning of a year centennial (centum – hundred) – every hundred years annuity – amount of money paid yearly

#61 lithos – Greek – stone megalith (megas – large) – large stone lithology (logos – study) – study of rocks or stone lithosphere (sphaira – ball, globe) – the rock crust of the earth

#62 petros – Greek – rock petrified (facio/factum – make, do) – made into rock petroleum (oleum – olive, olive oil) – oil from rocks petroglyph (glyphein – carve) – rock carving