🌐EnglishEnglishBahasa IndonesiaDeutschEspañolFrançaisItalianoPolskiPortuguêsTürkçeРусскийالعربيةفارسی한국어中文日本語EntityQ686707· pop 25· linked from 80 articlesfaint young Sun paradoxapparent mystery that the early Earth seems to have had liquid water, even though the young Sun was less bright, thus presumably completely freezing the EarthConnectionsHadeanEntitySunConceptMoonCategories1972 in scienceClimate historyParadoxesSunUnsolved problems in astronomy