Astrophysicist warns devastating asteroid strike 'just a matter of time'

An astrophysicist from Queen's University Belfast is warning that Earth is incredibly vulnerable to an asteroid strike.

That scientist is Alan Fitzsimmons and he believes, "it is a case of when an asteroid collision will happen, rather than if it will happen."

"Astronomers find Near-Earth Asteroids every day and most are harmless. But it is still possible the next Tunguska would take us by surprise, and although we are much better at finding larger asteroids, that does us no good if we are not prepared to do something about them," said Fitzsimmons.

See stunning space photos from astronaut Don Pettit's new book:

11 PHOTOS
Space photos from astronaut Don Pettit's new book
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Space photos from astronaut Don Pettit's new book

Star trails

Photographs can show us things that unaided human eyes cannot see. Mount a camera on a tripod, point it at the heavens, and open the shutter, and you can capture an image of curving streaks of starlight that reveal information about our planet and its position in the solar system. I have made such time exposures of space from Earth, so when I had the chance, I figured it was only fitting to make time exposures of Earth from space.

Don Pettit/NASA

Infrared

Human eyes can only see a limited slice of the full electromagnetic spectrum. Just beyond what we see as deep red at one end of our “visible spectrum” is infrared radiation, wavelengths that are rich with information about our environment, but escape our detection.... In this infrared photograph, lush green plant life appears as bright orange-red. Rocky crags and other barren geologic structures appear as dark green to blue-grey. Turbulent oceanic currents become visible as whitish veils, and coral reefs glow a tie-dyed yellow-green.

Don Pettit/NASA

The Bosphorus Strait, Turkey

From above, lights accentuate the places where people want to live, and darkness marks places where we prefer not to be. Dark and light tell a story—the story not only of where we are now, but also of where we have been. What was once a meandering cattle trail is now a super highway illuminated with sodium vapor lights. An urban core shaped by a modern master plan appears as a matrix laid out in a perfect grid. Older cities have more organic, even chaotic shapes. Oil fields appear as a pattern of mottled white spots; and fishing vessels surrounded by dark ocean look like star clusters in the night sky, creating new constellations for the zodiac.

Don Pettit/NASA

Sunshine on the International Space Station

Daytime views from space are joyful, offering a wonderful display of saturated color.

Don Pettit/NASA

Betisboka River delta in Madagascar

We are accustomed to seeing intensely colored photographs from space, scenes that present themselves as saturated treats for the eyes. Such brilliant images are central to any orbital photo essay. But if you strip away the colors, leaving only tones of black and white, the eyes discover new pleasures. Deprived of color, the mind searches for other details where new perspectives come into focus.

Don Pettit/NASA

Blue marble

From space I have been able to capture wide-angle oblique views of natural structures on Earth that stretch across half a continent, and telephoto views that showcase fine details. Light is the heart of these photographs. Low-angle sunlight casts long shadows, and gives depth. Noontime sun creates sun glint, intense lighting that causes surface water to act like a mirror directly reflecting the sun’s rays into the lens. Sun glint reveals ocean surface patterns that are invisible under any other lighting condition.

Don Pettit/NASA

Aurora

Auroras are diaphanous incandescent displays. Intense greens, reds, and blues move across your field of view like phosphorescent amoebas. The greens swirl below our orbit, and the reds flow by at our same altitude.

Don Pettit/NASA

Space station over aurorae

We fly through an aurora, and for a moment it is as if we have suddenly been miniaturized, and inserted into a neon sign.

Don Pettit/NASA

Solar panels in front of the terminator

Near the terminator, the line that separates day and night, noctilucent clouds gleam with the iridescence of an abalone shell.

Don Pettit/NASA

Self-portrait of Don Pettit in the space station cupola

Don Pettit/NASA

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A news release on the astrophysicist and his warning notes that Fitzsimmons "is highlighting the threat for Asteroid Day, a global event on 30 June. On that day in 1908, a small asteroid exploded over Tunguska in Siberia and devastated 800 square miles."

Professor Fitzsimmons is warning that a similar unexpected strike in today's world could easily destroy a major city and a larger asteroid could be more dangerous."

53 PHOTOS
Cassini postcards from space
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Cassini postcards from space

Viewing Saturn through different colored filters, Cassini created this psychedelic composition.

Photo Credit: NASA/JPL/Space Science Institute

This impossible criss-cross pattern was created when a shadow of Saturn’s rings fell across the real ones.

Photo Credit: NASA/JPL/Space Science Institute

A close-up of Pan

A skirt of material around its middle makes this moon look like a dumpling.

Photo Credit: NASA/JPL/Space Science Institute

This image shows how heat is distributed across the gas giant and its rings.

Photo Credit: NASA/JPL/Space Science Institute

Can you spot all three moons in this picture? The brightest is the icy Enceladus. Pandora appears below Enceladus, just above the rings, and Mimas hides in the lower right.

Photo Credit: NASA/JPL/Space Science Institute

Titan looks a lot like Earth in this composite image. Peering through the haze, Cassini revealed that this large moon has lakes and streams of liquid methane on its surface, making it one of the top spots to search for alien life in our solar system.

Photo Credit: NASA/JPL/Space Science Institute

That bright dot under Saturn’s rings is Earth, from 898 million miles away.

Photo Credit: NASA/JPL/Space Science Institute

It looks chilly, but Enceladus has a salty ocean on the inside that may be capable of supporting life.

Photo Credit: NASA/JPL/Space Science Institute

Small moons can have a big impact. Here, the 26-mile-wide Pan cuts a 200-mile gap through Saturn's rings. It shares the road with two faint little ringlets.

Photo Credit: NASA/JPL/Space Science Institute

The gravity of this five-mile-wide moon perturbs the orbit of the ring particles, carving ripples that gradually settle back down later.

Photo Credit: NASA/JPL/Space Science Institute

Because the material on the inner edge of the gap (the right side) moves faster than the little moon, the waves occur in front of Daphis. The material on the outer edge of the gap moves slower, and therefore form behind Daphnis.

Photo Credit: NASA/JPL/Space Science Institute

Cassini discovered geysers shooting out of Enceladus' south pole, which may provide a window into the ocean within.

Photo Credit: NASA/JPL/Space Science Institute

Some of the particles streaming from Enceladus’ south pole end up forming Saturn’s E ring, which is shown here—it’s the bright strip behind the moon.

Photo Credit: NASA/JPL/Space Science Institute

To make this colorful image, Cassini shot three radio wavelengths at Saturn’s rings, and the distortion of those signals revealed how material is distributed throughout the rings. Scientists translated that data into colors: red indicates a region where there are no particles smaller than two inches in diameter; regions where there are particles smaller than two inches are shown in green; blue regions contain particles smaller than a third of an inch.

Photo Credit: NASA/JPL/Space Science Institute

A colossal storm swept across Saturn’s northern hemisphere in 2010 and 2011, covering 500 times the area of the largest southern hemisphere storms. It eventually wrapped around the entire planet, stretching across 2 billion square miles.

Photo Credit: NASA/JPL/Space Science Institute

False-color mosaics captured short-term changes in Saturn’s giant storm.

Photo Credit: NASA/JPL/Space Science Institute

The sun brilliantly lights up Dione’s left half, while fainter illumination reflecting off of Saturn reveals the moon’s shadowy right side.

Photo Credit: NASA/JPL/Space Science Institute

Enceladus has a groovy surface, marked by ridges, cracks, and troughs. It has relatively few craters—tectonic processes renew the crust and keep it looking young. Cassini captured this image from a distance of about 730 miles.

Photo Credit: NASA/JPL/Space Science Institute

The sun glints off Titan’s northern polar seas. This moon is the only object in the solar system, besides Earth, that we know has liquid on its surface.

Photo Credit: NASA/JPL/Space Science Institute

The Huygens probe eyes its landing site on Titan. After separating from Cassini, the probe landed on Titan and sent back pictures and data from its surface.

Photo Credit: NASA/JPL/Space Science Institute

Saturn’s rings peek around the corner of this image of Enceladus’s icy surface.

Photo Credit: NASA/JPL/Space Science Institute

Cassini revealed how strange Hyperion is in 2005. Scientists still aren’t sure what gives the moon its spongey structure.

Photo Credit: NASA/JPL/Space Science Institute

Icy peaks stick up out of Saturn’s B ring, casting long shadows. These are some of the tallest structures in the ring system.

Photo Credit: NASA/JPL/Space Science Institute

Cassini helped solve the mystery of why Iapetus is two-toned. Because the moon is tidally locked—meaning one side of it always faces Saturn—another side of it is constantly smacked with debris as it moves, like bugs on a windshield. That debris creates the dark side, which heats up easily, so its ice sublimates and moves over to the white side and settles down there. So the dark side keeps getting darker, and the light side keeps getting lighter, resulting in the yin yang appearance here.

Photo Credit: NASA/JPL/Space Science Institute

Iapetus’s dark side transitions to its light side, creating an effect that looks shiny.

Photo Credit: NASA/JPL/Space Science Institute

Cassini captured the first close-up views of Iapetus in 2007. Here we see its ice-covered, bright side, and also a hint of the debris-strewn dark side.

Photo Credit: NASA/JPL/Space Science Institute

A false-color image highlights Titan’s lakes of methane and ethane.

Photo Credit: NASA/JPL/Space Science Institute

False colors indicate particle sizes inside the rings. Purple contains particles larger than two inches; green indicates particles smaller than two inches; and blue means particles are smaller still, at less than one third of an inch.

Photo Credit: NASA/JPL/Space Science Institute

Another beautiful view of the geysers of Enceladus.

Photo Credit: NASA/JPL/Space Science Institute

That’s no moon! Actually it is—it’s Saturn’s moon Mimas. But it looks like a Death Star thanks to Herschel Crater, which measures 81 miles across.

Photo Credit: NASA/JPL/Space Science Institute

The tiny moon Pan casts a long, needlelike shadow across Saturn’s outer A ring.

Photo Credit: NASA/JPL/Space Science Institute

Tethys soars past Saturn.

Photo Credit: NASA/JPL/Space Science Institute

A false-color view highlights Rhea’s scratches and craters.

Photo Credit: NASA/JPL/Space Science Institute

The speck in the center of this image is a moonlet measuring about 1,300 feet across. Cassini scientists discovered it thanks to its long shadow.

Photo Credit: NASA/JPL/Space Science Institute

A wave moves across the rings, creating vertical undulations like corrugated cardboard.

Photo Credit: NASA/JPL/Space Science Institute

Just a pretty picture of Saturn’s rings. The shadow of Mimas cuts across the lower left.

Photo Credit: NASA/JPL/Space Science Institute

Photo Credit: NASA/JPL/Space Science Institute

Dione passes in front of Saturn and its rings, forming what looks like a :neutral_face:.

Photo Credit: NASA/JPL/Space Science Institute

A giant hexagon, each side wider than Earth, sits at Saturn’s north pole. Exactly how it’s created remains a mystery.

Photo Credit: NASA/JPL/Space Science Institute

Saturn’s northern hemisphere, as seen by Cassini from 1.9 million miles away.

Photo Credit: NASA/JPL/Space Science Institute

Backlit by the sun, some of Saturn’s faintest rings become apparent.

Photo Credit: NASA/JPL/Space Science Institute

A star shines through the B ring. Fluctuating light from the star helps scientists measure the density of ice and dust particles in the ring.

Photo Credit: NASA/JPL/Space Science Institute

Ring shadows paint stripes across Saturn’s surface as Titan passes beneath the ring plane. The tiny white speck above the rings is the moon Prometheus, which is just 53 miles in diameter.

Photo Credit: NASA/JPL/Space Science Institute

This is not a work of abstract art. It’s Titan and Dione, posing in front of Saturn and her rings.

Photo Credit: NASA/JPL/Space Science Institute

Titan’s haze reflects light, creating this bright circle that looks like something out of The Ring (as if Saturn needed any more rings…). Enceladus passes in front of Titan, its southern geysers just barely visible.

Photo Credit: NASA/JPL/Space Science Institute

The plumes of water shooting from the bottom of Enceladus may contain clues to the ocean within—and any tiny lifeforms that may live there.

Photo Credit: NASA/JPL/Space Science Institute

Tethys (660 miles in diameter) looks tiny compared to the great gas giant. With a diameter of 72,367 miles, nine Earths could fit inside it in a straight line.

Photo Credit: NASA/JPL/Space Science Institute

 The outer layers of Titan’s thick atmosphere appear purple in this false-color image.

Photo Credit: NASA/JPL/Space Science Institute

Saturn’s largest moon, Titan, passes in front of the ringed planet. The bluish tint in this natural color image indicates that it’s winter in the southern hemisphere.

Photo Credit: NASA/JPL/Space Science Institute

A 1,250-mile-wide vortex spins at the center of Saturn’s giant hexagon. It’s about 50 times larger than the average hurricane eye on Earth.

Photo Credit: NASA/JPL/Space Science Institute

A false-color view of the vortex at Saturn’s north pole, whose winds whip at a blistering 330 miles per hour.

Photo Credit: NASA/JPL/Space Science Institute

Saturn has so many moons (62 at last count) that it’s not uncommon to see multiple moons in one shot. Here, Cassini captured three-in-one: Titan (the largest), Rhea (top left), and Mimas.

Photo Credit: NASA/JPL/Space Science Institute

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