Ghost Moon Setting
The moon sets over Chief Mountain on the eastern border of Glacier National Park, Mont. The mountain rises abruptly from the surrounding plains, earning it the name "Tower Mountain" from the Lewis and Clark Expedition. It was later renamed to honor the original Blackfoot monikor, "Great Chief."
Chief Mountain is a geological feature called a klippe. It was once part of a larger slab of tock thrust over this area of the Montana-Canada border by a fault. The rest of the slab gradually eroded away, leaving this 9,080-foot (2,768 m) tall holdout standing in isolation.
Cracks in the Ice
A spidery series of cracks mars the sea ice off the coast of Alaska in this picture taken by the Suomi National Polar-orbiting Partnership satellite. According to NASA Earth Observatory, a high-pressure system hovering over the region in late January brought warm temperatures and southwesterly winds, which in turn fueled ocean currents that fractured the ice. February storms later fueled the fracturing.
Clouds encroach over the plains in this picture taken from an airplane just east of Denver on the afternoon of April 8, 2013. The storm system moved across the state, bringing spring snows and sending temperatures plummeting. In two hours Monday evening, the temperature in Denver dropped from a spring-like 68 degrees Fahrenheit (20 degrees Celsius) down to 42 degrees F (5.5 degrees C). By 5:20 a.m. on Tuesday, Denver was shivering in mere 16 degree F (-8.8 degree C) temperatures.
Spiking Out to Settle Down
Sea urchin larvae begin their transformation into adulthood by sprouting spikes. These microscopic larvae ply the tides for about a month before settling down on rocky shorelines. New research published April 8, 2013 in the journal Proceedings of the National Academy of Sciences finds that high turbulence near rocky reefs gives larvae a clue to start searching for a grown-up home. The turbulence signals keeps larvae from wasting their time looking for rocks on sandy beaches.
Light in the Dark
In microgravity, flames behave differently than here on Earth. This beautiful blue bubble is part of a combustion experiment conducted aboard the International Space Station by astronaut Chris Cassidy. The goal was to learn how different fuels burn in space in order to develop better strategies for extinguishing fires in microgravity. Cassidy took this image on April 10, 2013.
Bad News for Bats
Bad news for everyone's favorite flying mammals: The U.S. Fish and Wildlife Service has confirmed that bats at Fern Cave National Wildlife Refuge in Alabama have white-nose syndrome. The disease is a fungus that grows on hibernating bats, causing them to exhibit often-fatal behavior such as flying outside in cold weather. In eastern North America alone. 5.7 million to 6.7 million bats have died of white-nose syndrome.
Fern Cave is the winter home for multiple bat species, including the largest documented colony of gray bats, which are federally endangered. So far, the U.S. Fish and Wildlife Service had detected the syndrome in two groups of tri-colored bats in the cave.
What in the World?
Here's a hump day guessing game for the visually inclined: What is this odd black-and-white object? Helpful hint: It acts something like your nose.
Are all the guesses in? This is an ultra-close look at a moth antenna. Male moths use their antennae to detect pheromones from females, which travel through the air in plumes (look out, your porch light may be surrounded). A new study published April 15, 2013 in the journal Proceedings of the National Academy of Sciences found that male moths aren't perfect at sniffing out the chemicals in these plumes, so they sometimes mate with strains of moths they wouldn't otherwise approach. The finding explains the number of hybrid moths in nature.
This Hubble image, which was captured and released on April 19, 2013, to celebrate the orbiting telescope’s 23rd year in orbit, reveals part of the sky in the constellation of Orion (The Hunter).
The Hubble observatory, which launched on April 24, 1990, captured the Horsehead Nebula (also known as Barnard 33) rising like a giant seahorse from the turbulent waves of gas and dust in this stunning infrared light image. "The result is a rather ethereal and fragile-looking structure, made of delicate folds of gas — very different to the nebula’s appearance in visible light," mission officials wrote in an image description Friday (April 19).
Amazing Electromagnetic Winds
The interaction between the sun and Earth isn't limited to light. This artist's conception shows how electromagnetic solar winds influence the Earth's magnetosphere and upper atmosphere. University of Texas at Arlington physicist Yue Deng is currently studying these solar winds and how their energy is distributed in the atmosphere.
"Right now, estimation of the amount of energy entering the Earth's thermosphere is not very precise and can be underestimated by 100 percent. We know even less about how that energy is distributed," Deng said in a March 11, 2013 statement. "This information is critical because if you put the same amount of energy at 400 kilometers the impact can be 100 times larger than if you put it at 100 kilometers."
This dinosaur mama has quite the brood to prepare for. An artist's reconstruction of Ampelosaurus shows this titanosaurian sauropod laying a clutch of eggs. These dinosaurs, which hailed from the Late Cretaceaous in Europe, would have measured about 50 feet (15 m) long from nose to tail.
Dinosaur eggs are big news in Spain, where paleontologists have just announced the discovery of eggs from four species of dinosaur in Lleida. Previously, only one type of dinosaur egg had been documented — now there are five, researchers report in the March 2013 issue of the journal Cretaceous Research.
Arctic Through a Porthole
A view of the icy Arctic at Svalbard, an archipelago halfway between Norway and the North Pole. Sixty percent of these remote islands are covered by glacial ice.