Space Wombats and Penguin Poop: Spying on Animals from Orbit

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Penguin Spotting, and Other Cool Satellite Tricks

You’d be surprised what you can see from 300 miles up

For Smithsonian Air & Space Magazine:

At first glance the picture might be an abstract oil painting or, less artistically, poppy seeds scattered on cream cheese. The “cheese” in this case is a field of ice off the coast of Antarctica, and the black seeds are emperor penguins. The photo was taken from space, and is a good example of how satellite imagery is helping biologists study wildlife populations in new ways. No scientist needed to set foot near the penguin colony or fly an airplane overhead: High-resolution images from an orbiting QuickBird satellite were good enough to monitor the colony’s health over time.

“The advent of remote sensing allows us basically to see some of these areas that you physically cannot get to, no matter how hard you try,” says Michelle LaRue of the University of Minnesota. She and her colleagues use high-resolution images purchased from DigitalGlobe, Inc., one of a few private companies that license satellite imagery to governments and academic researchers. Other scientists use free satellite images from Landsat and other government-run programs. Although those tend to be lower in resolution, they demonstrate how remote sensing is important for the literal big picture: The huge areas of land surveyed by satellite make possible research that couldn’t be done otherwise. That’s true whether the location is (like Antarctica) hard to get to, in a conflict zone, heavily populated, or just too darn big.

[Read the rest at Smithsonian Air & Space Magazine…]


Designing space telescopes the size of a dinner plate

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Could Future Telescopes Do Without the Mirror?

Tomorrow’s Hubble might be the size of a dinner plate.

For Air & Space Magazine:

Today’s telescopes can see better and farther than ever, but they have become expensive: NASA’s Kepler spacecraft, which discovered planets orbiting far-away stars, and the Large Synoptic Survey Telescope nearing completion in Chile, for example, each cost about half a billion dollars.

Researchers at Lockheed Martin have a radical proposal: Build the observatory without the telescope—sort of. The idea, called Segmented Planar Imaging Detector for Electro-optical Reconnaissance, or SPIDER, begins with large arrays of silicon chips called photonic integrated circuits (PICs). Each chip in SPIDER takes a wide-open image, like a mirror with no focusing point. Then a computer combines the images, gradually eliminating the blurring, in a method called interferometry. By the time thousands of PICs are combined, the image should be as sharp as one produced by a large—and expensive—telescope mirror.

[Read the rest at Air & Space Magazine]

Seeing the invisible monster at the Milky Way center

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This is my second print magazine feature for Smithsonian Air & Space Magazine. The first was about gravitational waves, published not long before the LIGO detector found the first gravitational wave signals. The new piece is about the black hole at the center of our galaxy, published just a few months before…well, read the article to see why this is a good time to be writing about that particular black hole.

The First Sighting of a Black Hole

We know one lurks at the center of the Milky Way, but to these astronomers, seeing will be believing

For Smithsonian Air & Space Magazine:

he center of the galaxy doesn’t look like much, even if you’re lucky enough to live in a place where the night sky is sufficiently dark to see the bands of the Milky Way. In visible light, the stars between here and there blur together into a single brilliant source, like a bright beam hiding the lighthouse behind it.

But in other types of radiation—radio waves, infrared, X-rays—astronomers have detected the presence of an object with the mass of four million suns packed into a region smaller than our solar system: a supermassive black hole.

Astronomers call it Sagittarius A*, or Sgr A* (pronounced “sadge A star”) for short, because it’s located (from our point of view) in the Sagittarius constellation. Discovering the Milky Way’s black hole has helped cement the idea that the center of nearly every large galaxy harbors a supermassive black hole. But despite mounting evidence for black holes, we still haven’t seen one directly. [Read the rest at Smithsonian Air & Space Magazine]

Listening to the sounds of the cosmos

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Last year, I went to a conference in Florida to hear — and in some cases meet — some of the leading thinkers in the study of gravitational waves. These waves are disturbances in the structure of spacetime itself, and could provide information about some exciting phenomena, if we can learn to detect them. The universe as heard in gravitational waves includes colliding black holes, white dwarfs locked in mutual orbits, exploding stars, and possibly chaotic disturbances from the very first instants after the Big Bang. This story marks one of my first big magazine articles, which I wrote for Smithsonian Air & Space magazine.

The Universe is Ringing

And astronomers are building observatories to listen to it

For Smithsonian Air & Space:

Think of it as a low hum, a rumble too deep to notice without special equipment. It permeates everything—from the emptiest spot in space to the densest cores of planets. Unlike sound, which requires air or some other material to carry it, this hum travels on the structure of space-time itself. It is the tremble caused by gravitational radiation, left over from the first moments after the Big Bang.

Gravitational waves were predicted in Albert Einstein’s 1916 theory of general relativity. Einstein postulated that the gravity of massive objects would bend or warp space-time and that their movements would send ripples through it, just as a ship moving through water creates a wake. Later observations supported his conception. [Read the rest at Air & Space….]