If you were looking up at the Moon on March 17, 2013 at 03:50:55 UTC, you might have seen one of the brightest “lunar flashes” ever witnessed. And it would have been visible with just the naked eye.
“On March 17, 2013, an object about the size of a small boulder hit the lunar surface in Mare Imbrium,” says Bill Cooke of NASA’s Meteoroid Environment Office. “It exploded in a flash nearly 10 times as bright as anything we’ve ever seen before.”
The scientists estimate that the flash came from a 40 kg meteoroid measuring 0.3 to 0.4 meters wide hitting the Moon, likely traveling about 90,000 km/hr (56,000 mph.) The resulting explosion packed as much punch as 5 tons of TNT.
Lunar meteors hit the ground with so much kinetic energy that they don’t require an oxygen atmosphere to create a visible explosion. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site.
When researchers looked back at their records from March, they found that the moon meteor might not have been an isolated event.
“On the night of March 17, NASA and University of Western Ontario all-sky cameras picked up an unusual number of deep-penetrating meteors right here on Earth” said Cooke. “These fireballs were traveling along nearly identical orbits between Earth and the asteroid belt.”
Though Earth’s atmosphere protected our planet’s surface from being hit by these meteors, the moon has no such luck. Its lack of an atmosphere exposes it to all incoming space rocks, and the NASA monitoring program has spotted more than 300 meteor strikes that reached its surface since 2005.
Part of the motivation for the program is NASA’s eventual intent to send astronauts back to the moon. When they arrive, they’ll need to know how often meteors impact the surface, and whether certain parts of the year, coinciding with the moon’s passage through crowded bits of the solar system, pose special dangers.
“We’ll be keeping an eye out for signs of a repeat performance next year when the Earth-Moon system passes through the same region of space,” Cooke said. “Meanwhile, our analysis of the March 17th event continues.”
The scientists also hope to use NASA’s Lunar Reconnaissance Orbiter to photograph the impact site to learn more about how the crash occurred.
Butterflies can’t see their wings. They can’t see how truly beautiful they are, but everyone else can. People are like that as well.
Butterflies have excellent vision. Similar to birds, butterflies are able to see in the ultraviolet spectrum; unlike birds, butterflies have the broadest spectrum of color vision known to exist in the animal kingdom. A compound eye is located on each side of the butterflies’ head and is made up of many little eyes pressed together into one. The tiny individual eyes are called facets, and are made up of six sides. Thousands of facets make up the two compound eyes. Unlike human vision, where we see one image, butterflies see thousands of small images at a time. Underneath the facets is a crystal cone that extends inwardly and forms a transparent rod. When light enters this rod, it has already been reversed twice, making its’ rays parallel so that light enters the rod in a straight line. Compound eyes aid in seeing into the UV, detecting movement, and seeing varied colors. The side location of their eyes enables them to see in different directions at one time, useful in detecting predators. However, butterflies cannot see detail from a distance and can only recognize the fine patterns of other butterflies from a few feet away. This would mean they are capable of seeing their own wings.
So basically this is one of those supposedly profound quotes that tries to make a point while being based on really shitty information and thus falls apart. Surely they could have found an analogy that doesn’t fly in the face of basic scientific observation if they wanted to send the “you’re more beautiful than you think” message..
“butterflies cannot see detail from a distance and can only recognize the fine patterns of other butterflies from a few feet away” - so they can’t really see how beautiful they are then huh?
Neil deGrasse Tyson: How the Moon May Have Formed
How was the Moon formed, and why doesn’t it have more iron or heavy metals? Neil deGrasse Tyson explains to Eugene Mirman how a collision with a Mars-sized object during the formation of the Earth may have led to the creation of the Moon. Enjoy this “Behind the Scenes video” from StarTalk Radio.
via Star Talk Radio.
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Sick Science! - Exploding Bubbles
The term “burst your bubble” takes on a whole new meaning when our science guy, Steve Spangler, is invited to the play date. It’s probably safe to bet that these are no ordinary bubbles, but it’s also no ordinary problem that we’re facing with rising carbon dioxide levels in our atmosphere.
via Spangler Science TV.
We never sit here under the weight of all this air, the 5 x 10^18 kg of atmosphere that sits above everyone on Earth, and say “Gosh, that sure is heavy!”
You don’t realize just how powerful that 1 bar (~100 kPa) of pressure is until a train car is filled with steam, allowed to cool, and then implodes ohmygod did that just happen?
For more implosion goodness, check out this awesome video from Veritasium.