those the moment the world s largest active volcano exploded back to life, lighting up the hawaiian sides, and an ash cloud so large it can be seen from space. scientists say magma had been building for nearly two years. so you knew this was coming. we knew it was coming. we just didn t know that it was going to be in the middle of the night after thanksgiving weekend. pilling over theight, molten summit, but volcanologists say any threat to communities would be weeks away. mauna loa is massive. eruptions over the past 200 years have sent lava flows across the big island of hawaii, but it s been dormant nearly 40 years. the last major eruption, in 1984, threatened the city of hilo. this eruption follows years of lava flows from mauna loa s much smaller but much more active neighbor, kilauea. take a look at this fountain of lava. we were there in 2018 when lava from kilauea wiped out hundreds of homes, reshaping the island