Mercury Is Shrinking

Almost 9 miles narrower

The solar system’s smallest planet is getting even smaller.

Mercury has shrunk almost nine miles in diameter over the past four billion years, according to a report published Sunday. The reason? The planet is cooling, making its single tectonic plate contract and warp the surface into rocky ridges.

"It is Mercury's version of a mountain belt," Paul Byrne, a planetary geologist and lead author of the study, told National Geographic. "It would be a very dramatic landscape." 

All of the planets in the solar system are getting colder, and Mercury is no exception, despite its proximity to the sun. But the process has taken a harder toll on the small planet, forming cliffs as tall as Mount St. Helens and ridges longer than twice the length of Florida.

The findings come from the Messenger spacecraft, which has circled Mercury since 2011. Now that the ship has successfully mapped the planet’s entire surface, earthbound scientists have a detailed map of the alien landscape.



"South Africa remains the principal source of rhino horn for the illicit trade," according to a report from the International Union for Conservation of Nature. The report estimates that 3,226 horns were taken from rhinos poached in Africa from 2009 to September 2012, which excludes last year's massive hike in rhino poaching.

"This is very much like our drug war on our U.S./Mexican border," Howard Buffett told reporters, referring to how illegal hunters from Mozambique infiltrate Kruger National Park (KNP) in South Africa.

The money will fund a 30-month campaign in Kruger National Park and provide rangers with a helicopter, an aerostat balloon, and land vehicles equipped with sensors to track down poachers.

In parts of Asia, rhino horns are worth more per ounce than gold. Believed to be a cure-all for everything from cancer to hangovers, one kilogram (2.2 pounds) of rhino horn can fetch between $65,000 to $100,000 in Vietnam.

Edna Molewa, South Africa's Minister of Water and Environmental Affairs, told Reuters that "fighting and winning the battle in South Africa is fighting and winning the battle in the world."