The curious phenomenon of the cicada’s periodical life cycle is the subject of much debate among scientists, who are limited to no small extent by the infrequency of the insect’s visits to the surface. Most agree, however, that climate shifts — notably the rapid warming following the end of the last ice age — have played a role.
There are seven species of periodical cicadas in North America, four bound to a 13-year cycle, three in a 17-year cycle. All are characterized by black and orange bodies, and males woo their mates with species-specific choruses that can be deafening in large numbers.
The genetic similarity of these seven species suggests a common ancestor in the last 8,000 years. And because emergence seems closely linked to soil temperature and moisture, it is likely that climate has played a role in both regulating their life cycles and cueing their appearance.
It still didn’t get very bright; it was invisible to the naked eye. But with digital cameras and dark skies, snapping pictures of it was a matter of knowing where to aim, something photographer Colin Legg knows very well. From Perth, Australia, he captured this lovely time-lapse video of the asteroid moving past Earth right at the time of closest approach, 19:24 UTC. And he captured more than just DA14; there are some other surprises in the video, too. Make sure to set it to full-screen.
You can see DA14 sliding through the video from top to bottom on the left side of the frame. But right after the video starts, a meteor plummets through the field of view, leaving behind what’s called a persistent train—a trail of vaporized rock that can glow for several minutes.
…a very big meteor burned up over Chelyabinsk, a city in Russia just east of the Ural mountains, and about 1500 kilometers east of Moscow. The fireball was incredibly bright, rivaling the Sun! There was a pretty big sonic boom from the fireball, which set off car alarms and shattered windows.
Slate’s Bad Astronomy blog continues to update with videos and photos as more information is revealed (and corrected). In the incredibly clear video above, you can see the meteor as it was recordedon February 15, 2013by a dashboard camera.
An almost-complete skeleton of a Mammoth has been found in an ancient Roman excavation site about 19 miles outside of Paris. It’s thought to be between 100,000 to 200,000 years old.
“Evidence this clear has never been found before, at least in France,” said Gregory Bayle, chief archaeologist at the site.
“We’re working on the theory that Neanderthal men came across the carcass and cut off bits of meat.”
Above, a clip of what Woolly Mammoth life might have been like, from the BBC natural history show Wild New World. Below, scientists dive further into what traits the Mammoth had to adapt to the freezing cold temperatures of the Ice Age:
Sesame Street explains the hurricane to kids in an episode originally created for Hurricane Katrina and set to air again this weekend in the aftermath of Sandy.