fbpx

DEATH FROM THE SKIES  Computer simulations reveal that most of the lethality of an earthbound asteroid (illustrated) comes from gusting winds and shock waves.

Winds and shock waves are most deadly, computer simulations of 1.2 million hits suggest

It won’t be a tsunami. Nor an earthquake. Not even the crushing impact of the space rock. No, if an asteroid kills you, gusting winds and shock waves from falling and exploding space rocks will most likely be to blame. That’s one of the conclusions of a recent computer simulation effort that investigated the fatality risks of more than a million possible asteroid impacts.

In one extreme scenario, a simulated 200-meter-wide space rock whizzing 20 kilometers per second whacked London, killing more than 8.7 million people. Nearly three-quarters of that doomsday scenario’s lethality came from winds and shock waves, planetary scientist Clemens Rumpf and colleagues report online March 27 in Meteoritics & Planetary Science.

In a separate report, the researchers looked at 1.2 million potential impactors up to 400 meters across striking around the globe. Winds and shock waves caused about 60 percent of the total deaths from all the asteroids, the team’s simulations showed. Impact-generated tsunamis, which many previous studies suggested would be the top killer, accounted for only around one-fifth of the deaths, Rumpf and colleagues report online April 19 in Geophysical Research Letters.

“These asteroids aren’t an everyday concern, but the consequences can be severe,” says Rumpf, of the University of Southampton in England. Even asteroids that explode before reaching Earth’s surface can generate high-speed wind gusts, shock waves of pressure in the atmosphere and intense heat. Those rocks big enough to survive the descent pose even more hazards, spawning earthquakes, tsunamis, flying debris and, of course, gaping craters.

While previous studies typically considered each of these mechanisms individually, Rumpf and colleagues assembled the first assessment of the relative deadliness of the various effects of such impacts. The estimated hazard posed by each effect could one day help leaders make one of the hardest calls imaginable: whether to deflect an asteroid or let it hit, says Steve Chesley, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who was not involved with either study.

The 1.2 million simulated impactors each fell into one of 50,000 scenarios, which varied in location, speed and angle of strike. Each scenario was run with 24 different asteroid sizes, ranging from 15 to 400 meters across. Asteroids in nearly 36,000 of the scenarios, or around 72 percent, descended over water.

The deadliness assessment began with a map of human populations and numerical simulations of the energies unleashed by falling asteroids. Those energies were then used alongside existing casualty data from studies of extreme weather and nuclear blasts to calculate the deadliness of the asteroids’ effects at different distances. Rumpf and his team focused on short-term impact effects, rather than long-term consequences such as climate change triggered by dust blown into the atmosphere.

(The kill count of each effect was calculated independently of the other effects, meaning people who could have died of multiple causes were counted multiple times. This double counting allows for a better comparison across effects, Rumpf says, but it does give deaths near the impact site more weight in calculations.)

Story continues after interactive graphic



Death from the skies 

A new project simulating 1.2 million asteroid strikes estimates how many deaths could result from each effect of a falling space rock (averages for three classes of asteroid simulated are shown in the interactive below). People who could have died from two or more effects are included in multiple columns. 

Click the graphic to explore the asteroid simulation data. 

potential-image


While the most deadly impact killed around 117 million people, many asteroids posed no threat at all, the simulations revealed. More than half of asteroids smaller than 60 meters across — and all asteroids smaller than 18 meters across — caused zero deaths. Rocks smaller than 56 meters wide didn’t even make it to Earth’s surface before exploding in an airburst. Those explosions could still be deadly, though, generating intense heat that burns skin, high-speed winds that hurl debris and pressure waves that rupture internal organs, the team found.

Tsunamis became the dominant killer for water impacts, accounting for around 70 to 80 percent of the total deaths from each impact. Even with the tsunamis, though, water impacts were only a fraction as deadly on average as land-hitting counterparts. That’s because impact-generated tsunamis are relatively small and quickly lose steam as they traverse the ocean, the researchers found.

Land impacts, on the other hand, cause considerable fatalities through heat, wind and shock waves and are more likely to hit near large population centers. For all asteroids big enough to hit the land or water surface, heat, wind and shock waves continued to cause the most casualties overall. Land-based effects, such as earthquakes and blast debris, resulted in less than 2 percent of total deaths.

Deadly asteroid impacts are rare, though, Rumpf says. Most space rocks bombarding Earth are tiny and harmlessly burn up in the atmosphere. Bigger meteors such as the 20-meter-wide rock that lit up the sky and shattered windows around the Russian city of Chelyabinsk in 2013 only frequent Earth about once a century (SN Online: 2/15/13). Impacts capable of inducing extinctions, like the at least 10-kilometer-wide impactor blamed for the end of the dinosaurs 66 million years ago (SN: 2/4/17, p. 16), are even rarer, striking Earth roughly every 100 million years.

Story continues after image

Large asteroid impacts are rare. Space rocks as big as the 20-meter-wide meteor that left behind a smoky trail across the sky above Chelyabinsk, Russia, in 2013, for instance, strike about once every 100 years. But to best prepare for such events when they do occur, a research group is assessing the relative deadliness of various effects.

OLEG KARGOPOLOV/AFP/GETTY IMAGES


But asteroid impacts are scary enough that today’s astronomers scan the sky with automated telescopes scouting for potential impactors. So far, they’ve cataloged 27 percent of space rocks 140 meters or larger estimated to be whizzing through the solar system. Other scientists are crunching the numbers on ways to divert an earthbound asteroid. Proposals include whacking the asteroid like a billiard ball with a high-speed spacecraft or frying part of the asteroid’s surface with a nearby nuclear blast so that the vaporized material propels the asteroid away like a jet engine.

The recent research could offer guidance on how people should react to an oncoming impactor: whether to evacuate or shelter in place, or to scramble to divert the asteroid. “If the asteroid’s in a size range where the damage will be from shock waves or wind, you can easily shelter in place a large population,” Chesley says. But if the heat generated as the asteroid falls, impacts or explodes “becomes a bigger threat, and you run the risk of fires, then that changes the response of emergency planners,” he says.

These asteroids aren’t an everyday concern, but the consequences can be severe.

— Clemens Rumpf

Making those tough decisions will require more information about compositions and structures of the asteroids themselves, says Lindley Johnson, who serves as the planetary defense officer for NASA in Washington, D.C. Those properties in part determine an asteroid’s potential devastation, and the team didn’t consider how those characteristics might vary, Johnson says. Several asteroid-bound missions are planned to answer such questions, though the recent White House budget proposal would defund a NASA project to reroute an asteroid into the moon’s orbit and send astronauts to study it (SN Online: 3/16/17).

In the case of a potential impact, making decisions based on the average deaths presented in the new study could be misleading, warns Gareth Collins, a planetary scientist at Imperial College London. A 60-meter-wide impactor, for instance, caused on average about 6,300 deaths in the simulations. Just a handful of high-fatality events inflated that average, though, including one scenario that resulted in more than 12 million casualties. In fact, most impactors of that size struck away from population centers and killed no one. “You have to put it in perspective,” Collins says.

Source: This article was published on sciencenews.org by THOMAS SUMNER

Categorized in Science & Tech

Our Prototypes column introduces new vehicle concepts and presents visuals from designers who illustrate the ideas. Some of them will be extensions of existing concepts, others will be new, some will be production ready, and others really far-fetched.

The concept

The Oxyde is a spacecraft/space module designed to carry robots to the asteroid belt located between Mars and Jupiter. It would also be used to pull smaller asteroids back closer to the Earth and Moon and could house engineers in charge of mining operations.


The background

Travelling within our solar system will probably become a possibility in the next 50 years. The next logical step will be to mine rare metals in space – if the numbers add up.

How will we do this? Will we develop multipurpose vehicles for this task? That’s the idea behind the Oxyde concept.

The Oxyde would fly into space by riding on top of a super heavy lift-launch vehicle.
The Oxyde would fly into space by riding on top of a super heavy lift-launch vehicle.

How it works

The Oxyde would be designed to carry humanoid robots into space. (See Robonaut 2by NASA.) It would not, however, be engineered to re-enter our atmosphere. It would fly out into space by riding on top of a super heavy-lift launch vehicle and remain there for the duration of its useful life.

The first Oxyde would be equipped with a chemical rocket powerful enough to reach the asteroid belt and bring back a small asteroid. Once it reached its destination, robonauts would exit the spacecraft and begin to survey and select suitable asteroids to mine.

Pulling an asteroid back to Earth will not be an easy task.The mass of the targeted asteroids would be limited by the thrust and fuel available on the Oxyde for the return trip. However, it would also be possible to send fuel to the surveying team once a candidate is selected.

Once the Oxyde is back near the moon, it could enter a lunar orbit with the asteroid and mining operations could begin.

At this point, a crew of human engineers could take their places aboard the Oxyde and live there to supervise mining operations. Basically, the Oxyde would become a space module for the mining crew.

The Oxyde would allow mining to take place in space, a necessary financial incentive for colonizing the solar system.
The Oxyde would allow mining to take place in space, a financial incentive to colonize the solar system.

What it’s used for

Would you like humans to colonize the solar system one day? If the answer is yes, then there will need to be a financial incentive, and mining is probably one of the best ones to attract investors. Of course, the cost will still be astronomical ($100-million (U.S.) for each launch, plus the spacecraft, preparation, etc.). There are thousands of unanswered questions, but this concept was meant first and foremost to continue the discussion around space mining .

The designer

I would like to thank Martin Rico for creating the images of the Oxyde concept. Rico lives near Buenos Aires and studied design at the University of Buenos Aires and now works as a freelance industrial designer. He also designed the Seataci Yacht concept and the Sutton and Maui snowboard and surfboard mobile rental units.

Source: This article was published theglobeandmail By CHARLES BOMBARDIER

Categorized in Science & Tech

Here’s what happened to global temperatures after the dinosaur-killing asteroid struck

The asteroid that wiped out the dinosaurs wreaked apocolyptic havoc on Earth due to circumstance rather than size, scientists have argued.

New research suggests the relatively minor nine-mile wide asteroid — equivalent to a grain of sand hitting a bowling ball — smashed into a huge lode of sulphur-rich rock, subsequently plunging the planet into a global winter and pulverising numerous species.

Scientists drilled a mile down into the 20-mile deep impact crater, located in the Gulf of Mexico, off the Yucatan peninsula, in a bid to further understand how the catastrophic end to the dinosaurs' 150 million year reign on earth came to such an abrupt end 68 million years ago..

The site, dubbed Chicxulub after its discovery by geologists in 1991, has long baffled scientists, who have so far unable to explain the ill-fitting scale of the impact — known to be 110 miles wide — compared to its catastrophic consequences.

But, after analysing extract samples from the crater, the team, led by Sean Gulick, professor of geophysics at the University of Texas at Austin and Professor Joanna Morgan, of Imperial College London, believe an answer may have been found.

"That asteroid struck Earth in a very unfortunate place," Gulick told The Sunday Times.Asteroid hit

"Had the asteroid struck moments earlier or later, it might have hit deep water in the Atlantic or Pacific. That would have meant much less vaporised rock. Sunlight could still have reached the planet's surface, meaning what happened next might have been avoided."

Morgan added: "The samples suggest more than 100bn tons of sulphates were thrown into the atmosphere, plus soot from the fires that followed.

"That would be enough to cool the planet for a decade and wipe out most life."

As a consequence the global surface air temperature decreased by at least 26C, with three to 16 years of subfreezing temperatures and a recovery time longer than 30 years, a recent research paper from Julia Brugger, of the Potsdam Institute for Climate Impact Research, concludes.

The results are to be revealed in the BBC2 documentary The Day the Dinosaurs Died, scheduled to air on Monday (15 May).

This theory mirrors a hypothesis put forward by Steve Brusatte, a paleontologist at Edinburgh University.

In a 2014 report in the Biological Reviews, Brusatte found dinosaurs were faring well over at the time of impact. However, the strike coincided with a period in the dinosaur biodiversity timeline that reduced the plant eating herbivore types who could have survived the impact.

The key to human life?

Programme presenters, Professors Alice Roberts and Ben Garrod, gained unique access, in part due to being scientists themselves.

Garrod, an evolutionary scientist, added: "Had the asteroid struck moments earlier or later, it might have hit deep water in the Atlantic or Pacific. That would have meant much less vaporised rock. Sunlight could still have reached the planet's surface, meaning what happened next might have been avoided."

Source: This article was published International Business Times By Alex Taylor

Categorized in Science & Tech

Here’s an artist’s rendering of a large asteroid breaking up as it begins to plow through Earth’s atmosphere. If it lands it could do a lot of damage, but how much would depend on its size and collision site.ATPACK223/ISTOCKPHOTO

Every now and then a really big rock from space comes careening through Earth’s atmosphere. Depending on its size, angle of approach and where it lands, few people may notice — or millions could face a risk of imminent death.

Concern about these occasional, but potentially catastrophic, events keeps some astronomers scanning the skies. Using all types of technologies, they’re scouting for a killer asteroid, one that could snuff out life in a brief but dramatic cataclysm. They’re also looking for ways to potentially deter an incoming biggie from an earthboard path.

But if a big space rock were to make it to Earth’s surface, what could people expect? That’s a question planetary scientists have been asking themselves — and their computers. And some of their latest answers might surprise you. 

For instance, it’s not likely a tsunami will take you out. Nor an earthquake. Few would need to even worry about being vaporized by the friction-heated space rock. No, gusting winds and shock waves set off by falling and exploding space rocks would claim the most lives. That’s one of the conclusions of a new computer model.

Explainer: What are Asteroids? 

It investigated the likely outcomes of more than a million possible asteroid impacts. In one extreme case, a space rock 200 meters (660 feet) wide whizzes 20 kilometers (12 miles) per second into London, England. This smashup would kill more than 8.7 million people, computers estimate. And nearly three-quarters of those expected to die in that doomsday scenario would lose their lives to winds and shock waves.

Clemens Rumpf and his colleagues reported this online March 27 in Meteoritics & Planetary Science. Rumpf is a planetary scientist in England at the University of Southampton.

In a second report, Rumpf’s group looked at 1.2 million potential smashups. Here, the asteroids could be up to 400 meters (1,300 feet) across. Again, winds and shock waves were the big killers. They’d account for about six in every 10 deaths across the spectrum of asteroid sizes, the computer simulations showed.

Many previous studies had suggested tsunamis would be the top killer. But in these analyses, those killer waves claimed only around one in every five of the lives lost.

Explainer: What is a tsunami?

Even asteroids that explode before reaching Earth’s surface can generate high-speed wind gusts, shock waves of pressure in the atmosphere and intense heat. Space rocks big enough to survive the descent pose  far greater risks. They can spawn earthquakes, tsunamis, flying debris — and, of course, gaping craters.

“These asteroids aren’t an everyday concern,” Rumpf observes. Yet clearly, he notes, the risks they pose “can be severe.” His team describes just how severe they could be in a paper posted online April 19 in Geophysical Research Letters.

Previous studies typically considered individually each possible effect of an asteroid impact. Rumpf’s group instead looked at them collectively. Quantifying the estimated hazard posed by each effect, says Steve Chesley, might one day help some leaders make one of the hardest calls imaginable — work to deflect an asteroid or just let it hit. Chesley is a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. (NASA stands for National Aeronautics and Space Administration.) Chesley was not involved with either of the new studies.

Story continues below image.

asteroid Earth
Computer simulations reveal that most of the deaths caused by an earthbound asteroid (illustrated) would come from gusting winds and shock waves.
puchan/iStockphoto
 

Land hits would pose the biggest risks

The 1.2 million simulated asteroid impacts each fell into one of 50,000 scenarios. They varied in location, speed and angle of strike. Each scenario was run for 24 different asteroids. Their diameters ranged from 15 to 400 meters (50 to 1,300 feet). About 71 percent of the Earth is covered by water, so the simulations let asteroids descend over water in nearly 36,000 of the scenarios (about 72 percent).

The researchers began with a map of human populations. Then they added in data on the likely energy that a falling asteroid would unleash at a given site. Existing casualty data from studies of extreme weather and nuclear blasts helped the scientists calculate death rates at different distances from a space rock’s point of impact. All that was then combined into the computer model to gauge how deadly each modeled impact would likely be.

Explainer: What is a computer model?

The most deadly one would have killed around 117 million people. Many asteroid hits, however, would pose no threat, the simulations found. More than half of asteroids smaller than 60 meters (200 feet) across caused zero deaths. And no asteroids smaller than 18 meters (60 feet) across led to deaths. Rocks smaller than 56 meters (180 feet) wide didn’t even make it to Earth’s surface before exploding in the atmosphere. Those explosions could still be deadly, though. They would generate intense heat that could burn skin, the team found. They also would set off high-speed winds that would hurl debris and trigger pressure waves that could rupture internal organs.

Where asteroids fell into the ocean, tsunamis became the dominant killer. The giant waves accounted for between seven and eight of every 10 deaths from these asteroid splashdowns. Still, the casualties from water impacts were only a fraction as high as those due to asteroids that smashed into land. (That’s because asteroid-generated tsunamis are relatively small and quickly lose steam as they plow through the ocean, the computer model showed.)

Heat, wind and shock waves topped the impacts from land smashups, especially if they hit near large population centers.

Bottom line: For all asteroids big enough to hit Earth’s surface, heat, wind and shock waves caused the most casualties overall. Other land-based effects, such as earthquakes and blast debris, resulted in fewer than 2 percent of total deaths, the computer projected.

Story continues below image.

Chelyabinsk meteor
Large asteroid impacts are rare. Here, a 20-meter- (66-foot-) wide meteor left behind a smoky trail across the sky above Chelyabinsk, Russia, in 2013. Space rocks that big only strike Earth about once every 100 years.
Alex Alishevskikh/Wikimedia Commons (CC-BY-SA 2.0)
 

Protecting Earth

While asteroids have the potential to kill, deadly impacts are rare, Rumpf says. Most space rocks that bombard Earth are tiny. They burn up in the atmosphere, causing little harm.

Consider the rock that lit up the sky in 2013 and shattered windows around the Russian city of Chelyabinsk. Such 20-meter- (66-foot-) wide meteors strike Earth only about once a century. Far bigger impacts are capable of wiping out species. An asteroid at least 10 kilometers (6 miles) wide that smashed into Earth 66 million years ago has been blamed for wiping out the dinosaurs. Such mega-events are especially rare, however. They may occur only once every 100 million years or so.

Today, astronomers scan the skies with automated telescopes scouting for those potential killer space rocks. So far, they’ve cataloged 27 percent of those 140 meters (450 feet) or larger whizzing through our solar system.

asteroid deflector
If a killer asteroid were detected, heading for Earth, NASA has plans for developing a spacecraft to slam into the space rock, deflecting it to a path that would miss us. Such a system is, however, at least some 20 years away. Once it is available, it might require a warning time of a year or two to target and redirect small asteroids.
NASA

Other scientists are analyzing how they might divert or catch an earthbound asteroid. Proposals include whacking the asteroid like a billiard ball with a high-speed spacecraft. Or perhaps part of the asteroid’s surface might be fried with a nearby nuclear blast. The vaporized material should propel the asteroid away like a jet engine.

Understanding the potential threats — and options available to deal with them — could offer guidance on how people should react to a warning that an asteroid was heading Earth’s way. It might help people decide whether it’s better to evacuate or shelter in place — or even mobilize space troops to try and divert the asteroid.

“If the asteroid’s in a size range where the damage will be from shock waves or wind, you can easily shelter in place,” Chesley says. He says this should work for even a large population. But if the heat generated as it falls, impacts or explodes “becomes a bigger threat,” he says “and you run the risk of fires — then that changes the response of emergency planners.”

Making such tough calls will require more information about what the asteroids are made of, says Lindley Johnson. He serves as the “planetary defense” officer for NASA in Washington, D.C. Those properties in part determine an asteroid’s potential for bringing devastation. Rumpf’s team couldn’t consider how those characteristics might vary, Johnson says. But several asteroid-bound missions are planned to provide some answers to such questions.

For now, making decisions based on the average deaths presented in the new study could be misleading, warns Gareth Collins. He’s a planetary scientist at Imperial College London. A 60-meter- (200-foot-) wide incoming space rock, for instance, would cause an average of 6,300 deaths in the simulations. But just a handful of high-fatality events inflated that average. These included one scenario that resulted in more than 12 million casualties. In fact, most space rocks of that size struck away from population centers in the simulations. And they killed no one. “You have to put it in perspective,” he advises. 


Death from the skies 

A new project simulated 1.2 million asteroid strikes on Earth. That let scientists estimate how many deaths could result from each effect of a falling space rock. (Averages for three of the classes of asteroids that were evaluated are shown in the interactive below. People who could have died from two or more effects are included in multiple columns.) 

Click the graphic to explore the asteroid simulation data. 
Screenshot 2
H. THOMPSON AND T. TIBBITTS

Power Words

(for more about Power Words, click here)

angle     The space (usually measured in degrees) between two intersecting lines or surfaces at or close to the point where they meet.

asteroid     A rocky object in orbit around the sun. Most asteroids orbit in a region that falls between the orbits of Mars and Jupiter. Astronomers refer to this region as the asteroid belt.

atmosphere     The envelope of gases surrounding Earth or another planet.

cataclysm     An enormous, violent, natural event. A meteor hitting Earth and wiping out most living species would qualify as a cataclysmic event.

climate     The weather conditions prevailing in one area, in general, or over a long period.

climate change     Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and the clearing of forests.

colleague     Someone who works with another; a co-worker or team member.

computer model     A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.

crater     A large, bowl-shaped cavity in the ground or on the surface of a planet or the moon. They are typically caused by an explosion or the impact of a meteorite or other celestial body. Such an impact is sometimes referred to as a cratering event.

data     Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. 

death rates     The share of people in a particular, defined group that die per year. Those rates can change if the group is affected by disease or other deadly conditions (such as accidents, natural disasters, extreme heat or war and other sources of violence).

debris     Scattered fragments, typically of trash or of something that has been destroyed. Space debris, for instance, includes the wreckage of defunct satellites and spacecraft.

deter     An event, action or material that keeps something from happening. For instance, a visible pothole in the road will deter a driver from steering his car over it.

diameter     The length of a straight line that runs through the center of a circle or spherical object, starting at the edge on one side and ending at the edge on the far side.

dinosaur     A term that means terrible lizard. These ancient reptiles lived from about 250 million years ago to roughly 65 million years ago. 

extinction     The permanent loss of a species, family or larger group of organisms.

friction     The resistance that one surface or object encounters when moving over or through another material (such as a fluid or a gas). Friction generally causes a heating, which can damage a surface of some material as it rubs against another.

mechanism     The steps or process by which something happens or “works.” 

meteor     A lump of rock or metal from space that hits the atmosphere of Earth. In space it is known as a meteoroid. When you see it in the sky it is a meteor. And when it hits the ground it is called a meteorite.

National Aeronautics and Space Administration     (or NASA) Created in 1958, this U.S. agency has become a leader in space research and in stimulating public interest in space exploration. It was through NASA that the United States sent people into orbit and ultimately to the moon. It has also sent research craft to study planets and other celestial objects in our solar system.

numerical     Having to do with numbers.

online     (n.) On the internet. (adj.) A term for what can be found or accessed on the internet.

organ     (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plant’s roots are organs that take in nutrients and moisture.

planetary science     The science of planets other than Earth.

population     (in biology) A group of individuals from the same species that lives in the same area.

pressure     Force applied uniformly over a surface, measured as force per unit of area.

propulsion     The act or process of driving something forward, using a force. For instance, jet engines are one source of propulsion used for keeping airplanes aloft.

range     The full extent or distribution of something. 

risk     The chance or mathematical likelihood that some bad thing might happen.

scenario     An imagined situation of how events or conditions might play out.

shock waves     Tiny regions in a gas or fluid where properties of the host material change dramatically owing to the passage of some object (which could be a plane in air or merely bubbles in water). Across a shock wave, a region’s pressure, temperature and density spike briefly, and almost instantaneously.

simulation     (v. simulate) An analysis, often made using a computer, of some conditions, functions or appearance of a physical system. A computer program would do this by using mathematical operations that can describe the system and how it might vary over time or in response to different anticipated situations.

solar system     The eight major planets and their moons in orbit around our sun, together with smaller bodies in the form of dwarf planets, asteroids, meteoroids and comets.

telescope     Usually a light-collecting instrument that makes distant objects appear nearer through the use of lenses or a combination of curved mirrors and lenses. Some, however, collect radio emissions (energy from a different portion of the electromagnetic spectrum) through a network of antennas.

tsunami     One or many long, high sea waves caused by an earthquake, submarine landslide or other disturbance.

wave     A disturbance or variation that travels through space and matter in a regular, oscillating fashion.

weather     Conditions in the atmosphere at a localized place and a particular time. It is usually described in terms of particular features, such as air pressure, humidity, moisture, any precipitation (rain, snow or ice), temperature and wind speed. Weather constitutes the actual conditions that occur at any time and place. It’s different from climate, which is a description of the conditions that tend to occur in some general region during a particular month or season.

Source : This article was published sciencenewsforstudents.org By THOMAS SUMNER

Categorized in Science & Tech

In this Feb. 15, 2013 photo provided by Chelyabinsk.ru, a meteorite contrail over the Ural Mountains' city of Chelyabinsk, about 930 miles east of Moscow, Russia. After a surprise meteor hit Earth at 42,000 mph and exploded over a Russian city in February, smashing windows and causing minor injuries, scientists studying the aftermath say the threat of space rocks hurtling toward our planet is bigger than they had thought. Meteors like the one that exploded over Chelyabinsk _ and those that are even bigger and more dangerous _ are probably four to five times more likely to hit Earth than scientists thought before the February mid-air explosion, according to three studies released Wednesday in the journals Nature and Science.

In 1990, a NASA scientist named David Morrison wanted to know his chances of being killed by an asteroid.

It seemed a bit paranoid. After all, no one had ever been killed that way, and there was only one documented meteorite injury. In 1954, an Alabama woman was sitting in her living room when an asteroid crashed through the ceiling, bounced off the radio and bruised her leg.

But just because it hadn't happened didn't mean it was impossible, and when Morrison and a colleague ran the numbers, considering both the chances of an asteroid collision and the potential damage, the results were disturbing. Though it seems counterintuitive, over a 50-year period, space rocks are about three times more likely to cause someone's death than an airplane crash and eight times more likely than a tornado.

Why? Because even though tornadoes occur fairly regularly, they kill fewer than 100 people every year. But if an asteroid the size of a 40-story building were to hit New York City - an unlikely, but not impossible, occurrence - two things would happen. Everyone would see a blinding flash, and seconds later millions of people would be dead.

Recently the legitimacy of this threat has gone mainstream. Before, people dismissed Morrison as a crank. But now, even members of Congress are asking NASA whether we're prepared. At a hearing in March, Congress grilled NASA Administrator Charles F. Bolden Jr. and two other officials about "threats from space." Representative Bill Posey, R-Fla., asked "What would we do" if a big rock was going to hit New York in three weeks? The panel looked at each other and said nothing. "Bend over and what?" Posey said.

After a pause, Bolden assured the panel that "these are very rare events" and that NASA isn't aware of any big rocks headed our way, but "if it's coming in three weeks, pray." No one laughed.

It may seem extraordinary that astronomers are so mystified, especially considering how much they do know about asteroids: that they are hunks of ice and metal drifting around the sun, that they come in all shapes and sizes, and that most of them cluster in an orbit between Mars and Jupiter called the asteroid belt. But the asteroids aren't confined to the belt - millions are spinning in orbits that overlap Earth's. Scientists call these "near-Earth asteroids," and our paths frequently cross. The small ones flare as harmless shooting stars. The biggest ones are thought to have caused mass extinctions.

This is how clueless even the world's best scientists are: Of the million or so asteroids that could wipe out a city, astronomers have discovered fewer than 1 percent, says Morrison, now 73 years old and a senior scientist at NASA. "Some of these are as dark as a lump of coal," he told Newsweek. Telescopes on the ground can't see them, and the only satellite telescope looking for them was dormant until just recently. These "city killers" tend to strike about once per century.

This last happened in 1908, when an asteroid tore through the atmosphere and burst several miles above a remote part of Siberia. Estimates suggest the asteroid was bigger than 200 feet across, but it flattened an area of forest larger than Los Angeles and Chicago combined. By comparison, the meteorite that landed near Cancún and (probably) killed the dinosaurs was six miles wide.

Even so, it wasn't until the early 1990s that NASA started searching for near-Earth asteroids. The first program began in earnest around 1994 when mile-wide comet fragments slammed into Jupiter, with one collision creating a five-mile fireball hotter than the sun. It was the first major impact humans had ever observed, and it got Congress's attention. Alarmed legislators responded by funding Spaceguard, a slow, ongoing effort to predict similar disasters on Earth. As of early this month, scientists had logged 10,599 near-Earth objects. (That includes comets, which are icier than asteroids, exist a light-year away and only swing by occasionally.)

On February 15, 2013, the largest asteroid to hit Earth since 1908 occurred over Chelyabinsk, an industrial city in Russia about 150 kilometers from the Afghanistan border. A 60-foot rock flew through the atmosphere at nearly 42,000 mph, and the heat of the friction created in the process blew it up like a nuclear bomb. A massive fireball and subsequent shockwave wobbled buildings and injured more than 1,000 people. No one saw it coming; NASA scientists on the asteroid project told 60 Minutes they learned about it on Twitter.

Posey says he was a proponent of planetary defense back when that was considered "kooky." At the age of 9, his father took him to see the Barringer Crater outside Flagstaff, Ariz., which was formed 50,000 years ago by a 150-foot asteroid. "What's to stop this from happening again?" he wondered.

Now 66, Posey says he still thinks the answer is "nothing." Speaking to Newsweek from his home in Melbourne, Fla., he said that having a plan is "important for national security and the survival of our species. I mean, it's going to happen again."

As for the survival of our species, we don't have to worry about that any time soon. Of the 1,000 near-Earth asteroids big enough to destroy civilization, 90 percent have been discovered. Impacts with these massive rocks are exceedingly rare, and none pose a threat in the foreseeable future.

Several international efforts to deflect an asteroid are under way, and the United Nations in October established plans for an International Asteroid Warning Network, a sort of planetary defense plan. Scientists are confident that if an asteroid (or, less likely, a comet) were headed our way, they could divert it by ramming it with a bomb or using a gravity tractor, a spacecraft of sufficient mass to tug an asteroid slightly toward it. With several years of warning, a minuscule diversion would swing it thousands of miles off course.

But without that warning time, evacuation would be the only option. In 2003, Clark Chapman, of the Southwest Research Institute, published a paper called "How a Near-Earth Object Impact Might Affect Society." In it, Chapman showed the probability of different size rocks hitting Earth this century (one-in-a-million for a 10-kilometer asteroid; 40 percent for a 30-meter asteroid). Then he outlined the kind of wreckage each might cause.

For a 50-meter rock, "fires might well be ignited beneath the brilliant explosion, unless it were cloudy," he wrote. "Weak structures might be damaged or even destroyed within a 20-kilometer radius by the shock wave and subsequent hurricane-force wind gusts. Exposed people and animals could be struck by flying objects."

NASA's best solution to find these rocks, an infrared-telescope satellite called NEOCam, is on a backburner, basically unfunded. And even if NASA had more money, the White House is much more interested in going to Mars. As for the U.N.'s International Asteroid Warning Network, it acts more like a curator of existing telescopes and wouldn't actually build new tools.

"Wouldn't it be ironic if we get wiped out even though we have the technology to do something about it?" says Ed Lu, chief executive officer of the B612 Foundation, an organization led by retired astronauts devoted to saving the planet. Lu says the issue first struck him as he drifted through space for six months on the International Space Station, "sitting in there and looking at the craters on the moon."

"We just felt we had to do it ourselves because very clearly no one else is doing it," Lu told Newsweek. The plan is to launch a privately funded telescope satellite called Sentinel that will find asteroids more rapidly than NASA can. Like the proposed NEOCam, its infrared telescope would reveal dark objects, and its view wouldn't be blurred by the atmosphere. The project will cost about $400 million - not much considering NASA received about $16.9 billion in funding in 2013.

After its scheduled launch in 2018, Lu says his team will chart at least 100,000 asteroids per year, including the few hundred yet undiscovered civilization destroyers. "Sentinel is going to find something that's going to hit the Earth," Lu says. Morrison, the NASA scientist, calls Sentinel "the answer."

Until then, as Bolden, says, "Things have happened. You gotta pray."

Source : This article was published in newsweek.com By BEN WOLFORD

Categorized in Science & Tech

Scientists have discovered what they believe is one of the biggest impact craters in the world near the Falklands Islands. They say the crater appears to date to between 270 and 250 million years ago, which, if confirmed, would link it to the world’s biggest mass extinction event, where 96 percent of life on Earth was wiped out.

The presence of a massive crater in the Falklands was first proposed by Michael Rampino, a professor in New York University, in 1992 after he noticed similarities with the Chicxulub crater in Mexico—the asteroid that created this crater is thought to have played a major role in the extinction of the dinosaurs 66 million years ago.

But after a brief report at the Falklands site, very little research was carried out. Now, a team of scientists—including Rampino—have returned to the area to perform an “exhaustive search for additional new geophysical information” that would indicate the presence of an impact crater.

Their findings, published in the journal Terra Nova, suggest the huge circular depression just northwest of the islands is indeed the result of the massive impact of an asteroid or meteorite. The basin, which is now buried under sediments, measures over 150 miles in diameter.

To analyze the site, the team, from the U.S., Argentina and Paraguay, looked at various aspects of the crater, including gravity anomalies and seismic reflection, which allows them to estimate sub-surface properties, along with differences in the chemistry of the rocks.

Their findings were consistent with other impact craters, with certain features being “very similar to that of the Chicxulub multi-ring impact structure.” They found there was a large magnetic anomaly, suggesting significant variation in rocks at the site, as well as gravitational variations “typical of very large impact structures.”

asteroid impactArtist impression of an asteroid impacting Earth.

NASA/DON DAVISFalklands impact craterThe proposed impact crater in the Falkland Islands. The islands are shown in yellow, while the regions of red show a notable increase in Earth's magnetism, characteristic of an impact.

NATIONAL CENTERS FOR ENVIRONMENTAL INFORMATION.

Researchers say the crater appears to date to the Late Paleozoic Era—around the same time as the Permian mass extinction event also known as the Great Dying. They believe the crater dates to between 270 and 250 million years ago, but say further investigations are needed to confirm this.

    “Future drilling in this basin is a must” they wrote. “If confirmed as a site of impact, then this structure would be one of the largest known impact structures on Earth.” In a statement, Rampino added: "If the proposed crater turns out to be 250 million years old, it could correlate with the largest mass extinction ever _ the Permian extinctions, which wiped out more than 90 percent of all species.”

    But not everyone is convinced of the link. Michael Benton, a paleontologist from the University of Bristol, told Newsweek in an email interview that while the discovery of an impact basin is interesting, it is not necessarily related to the Great Dying.

    ‘There have been several suggestions that the end-Permian mass extinction was linked to impact, including possible craters off Australia, and this one in the South Atlantic,” he says. “The link of the current crater to the extinction is hugely tenuous—it could be the cause, but evidence is not presented for that idea.

    “It is only tentatively identified as a crater, and its age is estimated as Late Paleozoic—so it could be millions of years older than the critical boundary. Further, there is no evidence elsewhere in the world of the fallout for impact—as we know from the later impact at the end of the Cretaceous [period], you expect to find a shopping list of ten or more indicators of impact scattered worldwide, such as shocked quartz and iridium enrichment, but these have not been found. The study of a new crater is massively important, but it’s unlikely it had anything to do with the end-Permian mass extinction.”

    Source : This article was published in newsweek.com By HANNAH OSBORNE

    Categorized in Science & Tech

    Planetary Resources' Leo space telescope, seen in this artist's rendering, with remote sensing capability to analyse the composition of asteroids. Space mining seems far fetched, but has already attracted some big-name investors.Planetary Resources via The New York Times

    Is water the new oil of space?

    It may be to Middle Eastern oil states such as Saudi Arabia and the United Arab Emirates, who are looking at space as a way to diversify out of the earthly benefits of fossil fuel.

    "Middle East oil states are investing in satellite technology and trying to transform their domestic economies into digital economies and knowledge-based economies," said Tom James of Navitas Resources an energy consultant based in London and Singapore.

    As space colonisers such as Elon Musk and Jeffrey Bezos (owner of The Washington Post) aspire to shrink the cost of space travel, interest has picked up among oil states and others in how to power space settlements using water and minerals mined from the heavens.

    A computer-generated rendering of several small robotic spacecraft mining a potential near-Earth asteroid.A computer-generated rendering of several small robotic spacecraft mining a potential near-Earth asteroid. AP Photo/Planetary Resources
     
     

    Oil states are investing in companies and infrastructure that could one day mine minerals and water found on the moon and in asteroids.

    "They are investing in it in order to attract business to the Middle East," James said. Oil states have large, empty spaces, relatively small populations and are located near the equator. The UAE has launched a multipronged effort to establish a space industry in which it has invested more than US$5 billion ($6.67 billion), and that includes four satellites already in space and another due to launch in 2018.

    "The Middle East is ideal for launching rockets and spaceships," James said. "It's the long-term solution. Oil and gas may not run forever. So they are looking to invest and be part of the new, future economy."

    The water is critical. It can be turned into hydrogen to fuel the spaceship, oxygen for breathing or left untouched for drinking and everyday use. Requiring only a four-day trip and containing lots of ice, the moon is a prime candidate for resource extraction.

    The interest in space mining and industrialisation has picked up in recent years as Musk, Bezos and others push outward. Part of the key to unlocking affordable space travel and space industrialisation is finding extraterrestrial materials such as water and minerals that do not have to be rocketed up from Earth.

    Goldman Sachs wrote a recent research note explaining that "space mining could be more realistic than perceived." The bank in the same report said the storage of water as a fuel could be a "game changer" by creating orbital gas stations.

    Most of the minerals will remain for use in space. Some rare, highly valuable commodities could be brought back to Earth. Goldman Sachs, for instance, was quoted in a 2012 interview with Planetary Resources that estimated that a football field-size asteroid could contain up to US$50 billion worth of platinum.

    "Asteroid mining could very quickly supply an emerging on-orbit manufacturing economy with nearly all the raw materials needed," according to the Goldman Sachs report.

    The possibilities are beginning to register with the business sector.

    "Within the next five years," James said, "mining and energy companies will start thinking about space mining before the shareholders start asking, 'What is your strategy?' and they answer, 'Oh, we don't have one.' "

    The technology already exists. NASA launched a billion-dollar mission in September to vacuum materials from an 2,000-foot-wide asteroid called Bennu. The spacecraft is scheduled to sidle up to the asteroid in 2018, extend its arm and pull in its cargo. The ship will return to Earth a couple of years later.

    But it is unclear whether mining on a wider scale is a real business, said Paul Chodas, an astronomer and asteroid expert with NASA.

    The technology is there, but it's not simple. Asteroids travel through space at tens of thousands of miles per hour. Tracking asteroids and determining their composition is difficult.

    "It's hard to determine which ones will have the most valuable minerals," Chodas said. He said it is doable, but "the question is cost-benefit. Is it worth the cost? We don't know yet. There is simply more work to be done to determine whether space mining is profitable. But it's promising."

    Chris Lewicki is chief executive of Planetary Resources, a Seattle-area company studying asteroids to find one that is an appropriate candidate for mining.

    Lewicki said the mining industry is a natural to make the first move when it comes to recovering space minerals because of its earthbound expertise. He foresees a small, robotic mining operation drilling for water on an asteroid in as soon as about 10 years.

    "This is how [the mining industry] continues," Lewicki said. Mining asteroids "isn't a space project. It's a resource project. In the same way having minerals and materials are very important for our economy, space becomes a new medium for furthering that economy."

    The regulatory phase got a major boost in 2015, when President Barack Obama signed legislation recognising asteroid resource property rights.

    The law recognises the right of US citizens to own asteroid resources and encourages the commercial exploration and utilisation of resources from asteroids.

    In addition to the UAE's space industry, Bloomberg News reports that the Saudis signed a pact with Russia in 2015 for cooperation on space exploration. Abu Dhabi is an investor in Richard Branson's space tourism venture, Virgin Galactic.

    Several private companies, including Deep Space Industries, Planetary Resources and Shackleton Energy, are trying to crack the mining potential.

    "If you have any significant human activity in space, then you are going to need resources," said Peter Stibrany, chief strategist and business developer for Deep Space Industries. "It will get too difficult to launch everything from the ground."

    Deep Space Industries is four years old and living off seed money from investors and founders. Stibrany said the company is in the technology development stage and working to create delivery systems for lower orbit launches.

    He said mining space resources faces what he calls a "four-dimensional problem."

    The first two are technological and regulatory, which are being addressed.

    "While the psychological barrier to mining asteroids is high, the actual financial and technological barriers are far lower," according to the Goldman Sachs report. "Prospecting probes can likely be built for tens of millions of dollars each, and Caltech has suggested an asteroid-grabbing spacecraft could cost $2.6 billion."

    James pointed to "nano-sats," small satellites priced relatively inexpensively at $2 million each, far less than the hundreds of millions needed to place current satellites in orbit.

    The third concern is the lack of a current market in asteroid resources. That should resolve itself when the space population hits critical mass, demanding infrastructure.

    Then a business will follow if investors see that a reasonable return is likely over a reasonable amount of time with appropriate risks. That is the fourth hurdle.

    "The end game," Stibrany said, "is that if you have 1,000 or 10,000 people living and working in space, there is no practical way that is going to work without using in-space resources."

    This article was  published in afr.com

    Categorized in Science & Tech

    A huge, shiny, peanut-shaped asteroid will safely swing by Earth tomorrow morning (April 19), coming within a distance of 1.1 million miles (1.8 million kilometers) of the planet — about 4.6 times the distance from Earth to the moon.

    The bright asteroid 2014 JO25  is coming toward Earth from the sun's direction and should be visible in the sky in small telescopes for a few days afterward as it fades from view. It will be at its closest point to Earth at 8:24 a.m. EDT (1224 GMT). You can see a video animation of the asteroid's orbit here.

    Asteroid 2014 JO25 was first spotted in May 2014 by astronomers at the Catalina Sky Survey in Arizona, and measurements from NASA's NEOWISE mission suggested it was about 2,000 feet (650 meters) across, according to NASA's Jet Propulsion Laboratory (JPL). Radar observations from the Arecibo Observatory in Puerto Rico suggest it could be as big as 4,270 feet (1.3 km) at its widest point.

     

    The asteroid's surface reflects about twice as much light as the moon. Its approach marks the closest an object this large has come to Earth since the gigantic asteroid 4179 Toutatis tumbled by in 2004, within 4 times the distance from the Earth to the moon.

    The Aricebo Observatory caught this radio image of the asteroid 2014 JO25 on April 17, 2017, as the large, peanut-shaped asteroid neared its closet approach to Earth.
    The Aricebo Observatory caught this radio image of the asteroid 2014 JO25 on April 17, 2017, as the large, peanut-shaped asteroid neared its closet approach to Earth.
    Credit: Aricebo Observatory/NASA/NSF

    Wednesday's approach is the closest 2014 JO25 has come in at least 400 years, and there's no known close approach coming through at least the year 2500. Although the asteroid's approach poses no risk to Earth — with a 0 percent impact probability — the International Astronomical Union's Minor Planet Center still classified it as "potentially hazardous" because of its size and nearness to Earth. Researchers will have to keep an eye on it to see if it drifts closer over the centuries, the Minor Planet Center wrote.

    Astronomers around the world will study asteroid 2014 JO25 during and after its approach, including skywatchers at Arecibo and NASA's Goldstone Solar System Radar in California, JPL officials said in the statement — making observations that can potentially reveal features just a few meters across.

    "Using radar, we can illuminate a near-Earth asteroid and directly measure its features,"astronomer Edgard Rivera-Valentín, a planetary scientist with the Universities Space Research Association (USRA) at the Arecibo Observatory, said in a separate statement. That's how scientists pinned down the asteroid's peanut shape, he added.

    The next close approach of a known giant asteroid will happen in 2027, when the half-mile-wide (800 m) asteroid 1999 AN10 passes by at about the distance from the Earth to the moon.

    The asteroid 2014 JO25 will fly safely past Earth April 19, coming within 1.1 million miles (1.8 million km) of the planet — about 4.6 times the distance between the Earth and the moon. This map shows the asteroid's locations as it passes through the sky April 19 to April 22 — it will appear bright in the sky for small telescopes for a few days after closest approach. Its position will vary from location to location; you can calculate its position on this NASA site.
    Credit: Gianluca Masi (Virtual Telescope Project)/TheSkySixPro

    You can watch asteroid 2014 JO25's journey live on the Slooh online observatory's website starting at 7 p.m. EDT (2300 GMT) April 19. You can also seek it out in the sky using the celestial map above and a small telescope (although its position will vary, depending on your location).

    While you're looking, keep an eye out for the comet PanSTARRS (C/2015 ER61), which will be visible in the dawn sky to observers with binoculars or a small telescope as it makes its closest approach of 109 million miles (175 million km).

    Editor's note: If you capture a photo of asteroid 2014 JO25 through a telescope and would like to share it with Space.com, please send images and comments in to: This email address is being protected from spambots. You need JavaScript enabled to view it..

    Correction: A previous version of this article incorrectly stated that the Aricebo Observatory is in Chile; it is Puerto Rico.

    Source: Space.com

    Categorized in Science & Tech

    An asteroid as big as the Rock of Gibraltar will streak past Earth on April 19 at a safe but uncomfortably close distance, according to astronomers.

    "Although there is no possibility for the asteroid to collide with our planet, this will be a very close approach for an asteroid this size," NASA said in a statement.

    Dubbed 2014-JO25 and roughly 650 metres (2,000 feet) across, the asteroid will come within 1.8 million kilometres (1.1 million miles) of Earth, less than five times the distance to the Moon.

    It will pass closest to our planet after having looped around the Sun. 2014-J25's will then continue on past Jupiter before heading back toward the centre of our Solar System.

    Smaller asteroids whizz by Earth several times a week. But the last time one at least this size came as close was in 2004, when Toutatis -- five kilometres (3.1 miles) across -- passed within four lunar distances.

    The next close encounter with a big rock will not happen before 2027, when the 800-metre (half-mile) wide asteroid 199-AN10 will fly by at just one lunar distance, about 380,000 km (236,000 miles).

    The last time 2014-JO25 was in our immediate neighbourhood was 400 years ago, and it's next brush with Earth won't happen until sometime after 2600.

    The April 19 flyby is an "outstanding opportunity" for astronomers and amateur stargazers, NASA said.

    "Astronomers plan to observe it with telescopes around the world to learn as much about it as possible," the US space agency said.

    Besides its size and trajectory, scientists also know that its surface is twice as reflective as that of the Moon.

    It should be visible with a small optical telescope for one or two nights before moving out of range.

    2014-J25 was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona.

    Also on April 19, a comet known as PanSTARRS will make its closest approach to Earth at a "very safe" distance of 175 million km (109 million miles), according to NASA.

    The comet has brightened recently and should be visible in the dawn sky with binoculars or a small telescope.

    Asteroids are composed of rocky and metallic material, whereas comets -- generally smaller -- are more typically made of ice, dust and rocky stuff.

    Both were formed early in the history of the Solar System some 4.5 billion years ago.

    Source : digitaljournal.com

    Categorized in Science & Tech
    WASHINGTON, APRIL 8:  

    A relatively large near-Earth asteroid will fly safely past our planet on April 19 at a distance of about 1.8 million kilometres — over four times the distance from Earth to the Moon, NASA said today.

    Although there is no possibility for the asteroid to collide with Earth, this will be a very close approach for an asteroid of this size.

    The asteroid, known as 2014 JO25, was discovered in May 2014 by astronomers at the Catalina Sky Survey in Arizona, US.

    Contemporary measurements by NASA’s NEOWISE mission indicate that the asteroid is roughly 650 meters in size, and that its surface is about twice as reflective as that of the Moon.

    At this time very little else is known about the object’s physical properties, even though its trajectory is well known.

    The asteroid will approach Earth from the direction of the Sun and will become visible in the night sky after April 19.

    It is predicted to brighten to about magnitude 11, when it could be visible in small optical telescopes for one or two nights before it fades as the distance from Earth rapidly increases, NASA said.

    Small asteroids pass within this distance of Earth several times each week, but the upcoming close approach is the closest by any known asteroid of this size, or larger, since asteroid Toutatis, a five-kilometre asteroid, which approached within about four lunar distances in 2004.

    The next known encounter of an asteroid of comparable size will occur in 2027 when the 800-metre-wide asteroid 1999 AN10 will fly by at one lunar distance, about 380,000 kilometres.

    The April 19 encounter provides an outstanding opportunity to study this asteroid, and astronomers plan to observe it with telescopes around the world to learn as much about it as possible.

    The encounter on April 19 is the closest this asteroid has come to Earth for at least the last 400 years and will be its closest approach for at least the next 500 years.

    Also on April 19, the comet PanSTARRS (C/2015 ER61) will make its closest approach to Earth, at a very safe distance of 175 million kilometres, NASA said.

    A faint fuzzball in the sky when it was discovered in 2015 by the Pan-STARRS NEO survey team using a telescope on the summit of Haleakala, Hawaii, the comet has brightened considerably due to a recent outburst and is now visible in the dawn sky with binoculars or a small telescope.

    (This article was published on April 8, 2017)

    Source : thehindubusinessline.com

    Categorized in Science & Tech
    Page 1 of 2

    airs logo

    Association of Internet Research Specialists is the world's leading community for the Internet Research Specialist and provide a Unified Platform that delivers, Education, Training and Certification for Online Research.

    Get Exclusive Research Tips in Your Inbox

    Receive Great tips via email, enter your email to Subscribe.

    Follow Us on Social Media

    Book Your Seat for Webinar - GET 70% OFF FOR MEMBERS ONLY      Register Now