space

December 3, 2013

Why ancient treasure is buried beneath your feet

Construction workers keep accidentally turning up important archaeological finds all over the world just by digging. One minute it’s just a shovelful of dirt and crud; the next you have a priceless artifact.

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Just this year:

Discoveries like this happen several times a year nowadays. We’re just beginning to wake up to what’s right under our noses.

Paul Mullins has some great insights on the contrast between the banality of parking lots and the excitement of discovery: What seems ordinary in one age becomes a priceless artifact in another. “There is a story to be told in all of these non-descript parking lots,” he says. “In the end it is not as banal as it might seem on first glance.”

The explosion of new discoveries goes beyond archaeology, too. For example: We’re just starting to realize how common meteor strikes are. We know that shooting stars happen every night, but only recently have scientists realized that 60 meteors have detonated in midair air since 1990 with enough force to register on devices meant to listen for nuclear bomb explosions. They usually go unnoticed at the time, happening over unpopulated areas.

The Guardian Newspaper collected records of every meteorite strike recorded since 861 AD and made this awesome animation from it. (And a global map). You can see that it’s only in the recent past that mankind has begun to notice and remember these things.

We’re living in a miraculous age.

November 28, 2013

You’re all wrong: The ISS is the 8th Wonder Of The World

They say the Great Wall of China is the only man-made object you can see from space. That’s not true, but if you turn the idea on its head you have something that IS true: The world has about 1,000 functioning satellites right now and they’re the only man-made objects you can see from anywhere in the world. The International Space Station is by far the most awesome of them. Look up at the right time tonight and you’ll see it. It’s the real eighth wonder of the world.

Lists of the wonders of the ancient world always include a big pile of stone blocks called the Great Pyramid. Lists of the wonders of the modern world usually include the Golden Gate Bridge and Canada’s CN Tower. Those are cool enough, but miles above them is a football-field-sized flying mansion and laboratory that the world’s 16 most powerful nations united to create. It literally runs circles around all the other wonders.

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It’s a stepping-stone into the rest of the universe. It’s the only wonder of the world that brought the world’s nations together in cooperation. It has a giant robot arm that on Earth could lift 220,000 pounds. They make their own air from water up there. It has brought us some amazing new scientific achievements, including finding clues to the mystery of dark matter. More than 300 astronauts from around the world have worked and trained up there, preparing for the future. Like Kennedy said about the mission to the Moon: “We do these things not because they are easy, but because they are hard.”

If you live in the middle of the U.S. (Wichita specifically), the International Space Station will fly directly above your head tonight at about 6:28.

You can find out when it’s visible in your area using a tool called The Astroviewer. Or find out from NASA. Looking up you’ll see what looks like a lone star following its own path across the sky.

So tonight, look up.

And realize that this is what they’re seeing when they look back down at night:

If you could see the Earth illuminated when you were in a place as dark as night, it would look to you more splendid than the moon.

-Galileo Galilei

Give thanks tonight that we live in a world of such wonder.

November 19, 2013

Today, a satellite built by high school kids was launched into orbit

minotaur-1-rocket-launch-hawaii-satellite-team

NASA launched 29 satellites on a single rocket today.

It’s a triumph of miniaturization and it’s the first step into a world where average people can put things into orbit.

All but one of the 29 are CubeSats, from groups around the country. They’re tiny satellites weighing no more than three pounds each and costing very little.

The main satellite was the Air Force’s $55 million ORS-3, built to help the military test new ways to automate satellite deployment. Everything’s getting automated these days.

The rest of the satellites all do a bunch of different things.

The Firefly satellite studies lightning, which strikes somewhere on Earth about 100 times a second. Firefly aims to help reveal how and why lightning can in rare cases produce bursts of gamma rays, which are normally only produced in stars or in nuclear bombs.

The satellite built by students at Thomas Jefferson High School in Virginia isn’t quite so lofty, but it’s still pretty great.

From the Washington Post:

Students anticipate that the satellite will stay aloft transmitting messages and live telemetry data — about its position in space — back to Earth for at least three months. The satellite is equipped with miniature solar panels and could remain in low-Earth orbit for up to two years.

Ultimately, the satellite is expected to fall into the Earth’s atmosphere and burn up, at which point the voice synthesizer will be programmed to say “I’m melting.”

November 6, 2013

60 asteroids have hit since 1990… And we didn’t notice.

In February, an asteroid screamed into the atmosphere above Russia so fast that it exploded in midair. It produced the explosive force of half a million tons of TNT.

It turns out asteroid strikes like the one that injured almost 1500 people this year are much more common than anyone thought. They just usually hit in remote areas — and even with all our technology and 7 billion pairs of eyes we haven’t noticed. An international team of scientists recently found out that “the strike rate of asteroids that are tens of metres in size is between two and 10 times higher than was previously thought.”

Why do meteors sometimes explode in midair? Coming from space, they’re very cold. They’re moving so fast that the air in front of them is compressed so much it produces incredible heat. The difference between extreme heat and extreme cold makes the space rock shatter into thousands of pieces. Those pieces are also moving at incredible speeds and compressing the air, producing even more heat, and you basically have an explosion. It doesn’t work the same way as a chemical explosion or nuclear explosion, but has similar force.

People often think that meteorites are radioactive because media reports often describe the power of meteor explosions in terms of the strength of a nuclear bomb. (February’s midair explosion had the force of twenty-five Hiroshima bombs). Meteor explosions can have similar strengths to nuclear bombs, but meteors are basically never radioactive.

There’s a global network of sensors set up by the US military and other groups to listen for nuclear explosions to enforce a nuclear test ban treaty. Some of those sensors can hear the really loud low-frequency atmospheric rumblings of a nuclear explosion from very far away.

An international team of scientists examined records from those sensors for readings that match the signatures of exploding meteors. They found 60 of them since 1990 that were up to 20 meters across.

Smaller-scale meteors fall on Earth all the time. I just saw a shooting star last week.

Last month, a meteor blew up in midair over Columbus, Ohio.

No damage. We’re lucky these things usually blow up in the sky instead of on the ground.

UPDATE: There was another meteor fireball over California a few hours ago.

November 5, 2013

,This is what Sunday’s eclipse looked like from space.

EclipseAnimation_11-3

The University of Wisconsin put together and animated satellite photos of the Moon’s shadow crossing the Earth on Sunday. The animation lasts only three seconds, but the actual eclipse lasted about five hours. (link via Bad Astronomy)

Seeing the eclipse from space makes me feel different about eclipses. I saw a total solar eclipse when I was little, and it was so weird that night seemed to come in the middle of the day. But here you can see it’s just a shadow briefly passing over your relatively tiny part of the planet.

People have always associated solar eclipses with doom. In ancient times, whole societies panicked during eclipses, and even today they sometimes still do. But eclipses aren’t rare: Every year sees two eclipses that are at least partial.

You’ll see more doomsday predictions in 2015. People will be saying that a solar eclipse over the Atlantic ocean that happens on March 20 (that year’s Jewish new year) has to mean doomsday is near. (They already are.)

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Here’s what the 2015 eclipse will look like. That fleeting black dot is the only part that will see a full eclipse.
Not pictured: Doom.

November 3, 2013

America woke up this morning to a hybrid solar eclipse

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Credit: Agence France-Press via BBC

People on the East Coast this morning could see the beginning of a hybrid eclipse sweeping across the Atlantic and Africa, climaxing half a world away.

A hybrid eclipse is one that starts out as one kind of eclipse but morphs into another. In this one, as the moon slides across the sun its distance means it isn’t quite big enough to completely block out the sun. There’s still a “ring of fire” shining around the moon even when it should be completely blocking the sun. They call that an annular eclipse.

As the moon’s shadow slides across the Earth, the globe’s curve brings the shadow a little closer. Later in the eclipse, it becomes big enough to give us a total eclipse, completely blocking the sun.

An eclipse where the distances involved are so delicately balanced that the Earth’s shape can change it from an annular to a total eclipse is rare. It isn’t a once-in-a-lifetime thing, it’s once in two lifetimes. We won’t see another one like this for 160 years.

September 20, 2013

What’s Einstein doing under your nose?

Public Domain art from NASA

There’s more than 2 dozen of these machines zipping around the Earth like a giant diagram of an atom, moving so fast it bends space and time.  (image source)

The link: Every day, people rely on Einstein’s time-warp equations without even thinking about it.

The story:

I’m Jay Knitig.  (It’s pronounced “Kinetic.”)  I’m a student at Wichita State University.

What I’m doing here is exploring the awesomeness of everyday life.  Our world is full of amazing things we usually don’t think about or even notice.

The wonders of science are right under your nose.  For example: Albert Einstein’s theory of relativity is abstract and hard to understand, but without realizing it you probably use it in everyday life.  It says that time and space aren’t the same for everyone: Time passes slower the faster you go, and things get smaller.

They don’t just seem smaller and slower, they actually are smaller and slower in your frame of reference.  It’s true for you but something else is true for them.  If one person is traveling at nearly light-speed and another isn’t, they could disagree about which of two events happened first, and both be right.  That’s relativity.

If you have a smartphone, it probably has GPS.  Even if you don’t, a lot of the trucks that deliver stuff to the stores you shop at use it.  GPS relies on a “constellation” of satellites that constantly zoom around the Earth at about two and a half miles per second triangulating with other satellites and your device on the ground.  At that speed (still a tiny fraction of light speed), time has actually slowed down a little for the satellites.

The GPS system people use every day employs Einstein’s time-bending equations to make up the difference.  Without Einstein’s equations, GPS couldn’t work.

Everyday life is full of awesome mind-boggling things just like that.  There are crazy, wonderful things all around us.

You have Einstein right under your nose.