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Hank explains the enormity of the Giant Magellan Telescope, possibly the biggest telescope ever built, as well as updates about NASA's new mission to the moon, and an unusual discovery about the habits of deep-sea squid.

Biggest Telescope Ever:

New Mission to the Moon:

Deep-Sea Squid:

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 Introduction (00:00)

From the habits of deep-sea squid to strange lights on the moon, science is solving some pretty weird mysteries we found out this week, and were probing ever deeper into space and time to answer even bigger questions. I'm Hank Green, and this is SciShow News.

[intro music]

 Biggest telescope ever? (00:24)

This week engineers reached a milestone in constructing what will become the largest optical telescope ever built. For a while, anyway.

The Giant Magellan Telescope, which will be built in Chile's Atacama Desert, will be as high as a twenty two storey building and will consist of seven giant mirrors, each eight-and-a-half meters across. Last Saturday the third of those seven mirrors was successfully forged, cast from molten glass in an enormous specialized furnace at the University of Arizona. And the first mirror built for the GMT has finally finished its polishing phase. In order to get its perfect shape and smoothness, engineers buffed it down to within a twenty five nanometer margin of error, less than a thousandth of the width of a human hair.

So despite being Earth-bound the GMT will be able to use these mirrors to collect enough light to see images with ten times the resolution of Hubble, and this will help us see 13.7 billion years back in time. By picking up ancient light traveling across the universe from as far back as a hundred thousand years after the Big Bang, astronomers hope to observe the formation of the very first stars and galaxies.

In addition to helping solve mysteries about the formation of the physical universe, the GMT will usher in the next class of massive super hi-def ground based telescopes. And it's not alone! An even larger apparatus, called the Thirty Meter Telescope, is planned to begin construction in Hawaii next year. For now GMT has a head start and may hold the 'biggest telescope' title if only briefly, but both astronomical behemoths are scheduled to be on line nine years from now in 2022.

 New mission to the moon (1:59)

Fortunately we only have to wait a few days before the September 6th launch of NASA's Lunar Atmosphere and Dust Environment Explorer. The new lunar probe, about the size of a small car, will orbit the moon for a hundred and forty days, collecting data on the composition of the moon's ultra thin atmosphere. Although it's less than one hundred trillionth the density of Earth's, the moon nevertheless has an atmosphere and scientists think it may be much like those on other moons, small planets, and even large asteroids. So in addition to teaching us what those bodies may be shrouded in, the mission also hopefully solve the decades-old mystery of moon-glow, the strange, streaky bands of lights that several Apollo astronauts have observed just before lunar sunrise.

Astronomers suspect the glow is caused by dust from the moon's surface becoming charged and electrostatically lifted by the sun's rays. So among many other things, the lunar probe will be looking for dust in the lunar atmosphere to test the theory.

 Deep-sea squid (2:50)

Meanwhile back on Earth biologists from the Monterey Bay Aquarium and other Californian institutions are trying to solve another mystery, this one about deep-sea squid. In a new study published in Proceedings of the Royal Society B on Wednesday, scientists say that they've observed, in the wild, for the first time ever, the squid known as Grimalditeuthis bonplandi. I don't know how to say it.

Scientists have known about this giant gelatinous creature for about a hundred years, mainly from finding it in the guts of whales and deep-sea fish, but it has confused biologists all this time because its unique tentacles seem... kind of useless. Extremely thin and fragile and without any suckers or hooks, the tentacles seem like they wouldn't be strong, fast, or sticky enough to catch any prey.

So the team used remote controlled submersibles to observe seven of the squid in their natural environment and found them undulating and flapping their seemingly worthless tentacles. The researchers discovered that the limbs imitated the movements of fish and worms, the things that crustaceans and small squids like to eat. Turns out the squids were using what's called 'aggressive mimicry': imitating harmless organisms in order to get closer to their prey.

If there's anything squid do that isn't cool I have not heard of it.

 Outro (4:03)

If there's any other mysteries you'd like us to solve please don't hesitate to tell us in the comments below or on Facebook or Twitter where I know you are already following us, and don't forget to go to and subscribe so you can keep on getting smarter with us. Thanks for watching.