Back in 2015, an underwater volcano near the main island of Tonga belched enough magma that it broke the ocean’s surface. This new land mass, smack-dab between the islands of Hunga Haʻapai and Hunga Tonga, is named “Hunga Tonga-Hunga Haʻapai” (or HTHH) and is officially the youngest island in the world.
HTHH is also only one of three volcanic islands to pop into semi-permanent existence in the last 150 years. This means that scientists at NASA can study its formation via satellite technology and use what they learn from the eruption to better understand the surface history of Mars. The more we know about Martian geology, the easier it will be to figure out if life existed there in the past and how difficult it would be for humans to terraform the red planet.
On a side note, adventurers just got a huge incentive to visit the South Pacific, where they have the opportunity to set foot on the youngest landmass on Earth. While you can fly to Tonga from the US via Auckland or Fiji, you will have to rent a boat and possibly swim to shore (while facing the risks of being next to an active volcano), but what a check for your travel bucket list!