Three European satellites launched Friday on a mission to study why the magnetic field surrounding Earth appears to be weakening.
The four-year study will collect data and map the field, which protects the planet (and us) from solar radiation.
Scientists say the field’s strength has weakened by about 15 percent in the last 200 years.
The weakening could be a sign of “polarity reversal" - when the field flips end-to-end, turning north into south. The phenomenon occurs every 200,000 to 300,000 years. But the last time the field flipped was almost 800,000 years ago.
The magnetic field is believed to be generated by the Earth’s molten iron core. The field reaches thousands of miles into space and creates a bubble around the earth. It’s what makes compasses work, and aids everything from navigation systems to animal migrations…
Far off the coast of Yemen lies isolated Socotra island, where hundreds of plants and animals have developed into species unique to the island. The best-known of these might be the Dragon Blood trees, with their densely-packed crowns and blood-red sap. Socotra, sometimes referred to as “the Galapagos of the Indian Ocean,” is slowly emerging from its long isolation — in 1999, the first airport opened, and tourism began to pick up. In an effort to counter any negative impacts, UNESCO recognized the island as a World Natural Heritage Site in 2008, promoting conservation of the unique environment and some of its endangered species.
See more photos from Hokkaido’s Blue Pond by visiting the 青い池 (Blue Pond) location page.
In a crater atop Mount Meakan (雌阿寒岳), there sits one of Japan’s most Instagrammable sights: the iridescent Blue Pond (青い池).
The pond’s origins are recent. After nearby Mt. Tokachi erupted in 1988, the regional government constructed a damn to protect nearby towns from volcanic mudflows. The resulting body of water, also commonly called Aonuma (青沼), owes its bright color to a high concentration of aluminum hydroxide, which reflects blue light. Blue Pond is just one of five volcanic lakes in the region formed after the eruption, and each has its own distinctive color.
The pond is a popular destination for tourists during the warmer months, but its location in the northern part of the country makes it difficult to access during winter snows.