Farms outside Baghdad as seen from a U.S. Army Blackhawk helicopter. Much of Iraq's soil has a high salt content because of flooding and poor drainage. Jim Gordon/U.S. Army Corps of Engineers/Flickr hide caption
Magnified 25,000 times, this digitally colorized scanning electron micrograph shows Ebola virus particles (green) budding from an infected cell (blue). CDC/NIAD hide caption
A geologist maps the margin of the lava flow in the open field below Cemetery Road near the town of Pahoa on the Big Island of Hawaii. Dozens of residents from the village may be forced to evacuate. AP hide caption
Caltech biochemical engineer Frances Arnold was awarded a National Medal of Technology and Innovation by President Obama in 2013. Jason Reed/Reuters/Landov hide caption
Caribous doing their business in mountain ice have left a viral record hundreds of years old. Courtesy of Brian Moorman hide caption
After a hard day of bruising battle, ancient gladiators reached for a post-workout drink, according to an ancient account. New research backs that up. Stefano Bianchetti/Corbis hide caption
Patients with certain kinds of brain damage can wind up with locked-in syndrome: they may be able to think just fine, but are unable to communicate their thoughts to others. A recently published case study shows that a non-invasive brain-computer interface can help. iStockphoto hide caption
Google vice president Alan Eustace is lifted by a balloon into the stratosphere, in a record-breaking skydive over New Mexico Friday. Paragon Space Development Corporation/Reuters /Landov hide caption
Image of sunspot AR 2192 Alan Friedman/Randall Shivak/Averted Imagination hide caption
The Limbic Reward System lights up when curiosity is piqued. LA Johnson/NPR hide caption
"It's a story that, in one sense, makes us feel very small and very little." - David Christian James Duncan Davidson / TED/TED hide caption
"Who are we? That is the big question. And essentially we are just an upright-walking, big-brained, super-intelligent ape." - Louise Leakey Courtesy of TED hide caption
"When did we originate as a species? How long have we been divergent from each other?" - Spencer Wells Andrew Heavens/TED hide caption
"We have a whole lot of power over what lives or dies on this planet and we have to think very carefully about what that means and how we're using it." -Juan Enriqez James Duncan Davidson/TED hide caption
"Even as a paleontologist, I imagine them fighting, I imagine them roaming around; they still fuel my imagination." - Jack Horner James Duncan Davidson/TED hide caption