Trilobites: Why Does Fall Foliage Turn So Red and Fiery? It Depends. Many of the hypotheses for why leaves turn red before they fall off trees in the autumn sound contradictory. Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:SpaceX breakthrough: Major boost as Elon Musk reveals success in untethered flight planSpace weather forecast: Solar storm to batter Earth’s southern hemisphere this weekJudge Blocks Trump Rule Requiring Drug Companies to List Prices in TV AdsSpaceX: Watch spectacular video of SpaceX Falcon Heavy fairing's Earth re-entryMoon landing anniversary: Richard Nixon’s speech in case of disaster REVEALEDMoon bombshell: UK scientists revive Soviet-era spacecraft in hunt for water in space