Yama Tkoi

Selasa, 30 April 2019

NASA head issues meteor warning, calls for cooperation to meet threat - NBCNews.com

April 30, 2019, 3:09 PM UTC / Source: CNBC.com

By Chloe Taylor, CNBC

Meteors that could destroy an entire U.S. state are a real threat to Earth, NASA’s chief warned on Monday.

Speaking at the Planetary Defense Conference in Washington, D.C., NASA Administrator Jim Bridenstine warned that the risk posed by meteor crashes was not being taken seriously.

“This is not about Hollywood, this is not about movies, this is about ultimately protecting the only planet we know right now to host life,” he said.

Bridenstine pointed to the meteorite that exploded over the Russian city of Chelyabinsk in 2013, which had “30 times the energy of the atomic bomb at Hiroshima” and injured around 1,500 people. Just 16 hours after the crash, NASA detected an even larger object that approached the earth but did not land on it, he revealed.

NASA Administrator Jim Bridenstine at the Planetary Defense Conference at the University of Maryland on April 29, 2019.Joel Kowsky / NASA

“I wish I could tell you that these events are exceptionally unique, but they are not,” Bridenstine said. “These events are not rare — they happen. It’s up to us to make sure that we are characterizing, detecting, tracking all of the near-Earth objects that could be a threat to the world.”

According to scientific modeling systems, such events are expected to happen once every 60 years — but Bridenstine pointed out that destructive meteorites had crashed on the earth three times in the last century.

In 2018, the White House published an action plan that required NASA to detect, track and characterize 90 percent of near-Earth objects measuring 140 meters (460 feet) in diameter — but Bridenstine admitted on Monday that the space agency had a long way to go to meet that goal.

“We’re only about a third of the way there,” he said. “We want more international partners that can join us in this effort. We want more systems on the face of the Earth that can detect and track these objects, and we want to be able to feed all of that data into one single operating system so that ultimately, we have the best, most accurate data that we can possibly get.”

Bridenstine warned that failing to invest in such a network could have catastrophic consequences.

”(At 140 meters) it’s big enough to destroy a state in the United States of America,” he said. “It’s big enough to destroy an entire European country.”

“We know for a fact that the dinosaurs did not have a space program,” he added. “But we do, and we need to use it.”

Earlier this month, NASA awarded a contract to Elon Musk’s SpaceX that will see the company provide launch services for the agency’s Double Asteroid Redirection Test (DART) mission. The $69 million mission, expected to launch in 2021, will test the earth’s capability of deflecting an asteroid by colliding a spacecraft with it at high speed.

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2019-04-30 15:09:00Z
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Electrical issue on Station delays Dragon launch - NASASpaceflight.com

Electrical issue on Station delays Dragon launch – NASASpaceFlight.com

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2019-04-30 13:44:43Z
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NASA chief warns asteroid threat is real: ‘It’s about protecting the only planet we know to host life' - Fox News

NASA Administrator Jim Bridenstine is sounding the alarm that an asteroid strike is not something to be taken lightly and is perhaps Earth's biggest threat.

Speaking at the International Academy of Astronautics' 2019 Planetary Defense Conference in College Park, Md., on Monday, Bridenstine said the space agency and other asteroid scientists need to make sure people understand that the threat is very real and not just the imagination of big-budget blockbuster movie directors.

"We have to make sure that people understand that this is not about Hollywood, it's not about movies," Bridenstine said at the conference, according to Space.com. "This is about ultimately protecting the only planet we know right now to host life, and that is the planet Earth."

NASA GAMEPLANS MASSIVE ASTEROID STRIKE

"We know for a fact that the dinosaurs did not have a space program. But we do, and we need to use it," Bridenstine added, attempting to portray planetary defense on the same level as a return trip to the Moon. The Trump administration wants to see astronauts return to the Moon by 2024, with or without the help of NASA.

NASA Administrator Jim Bridenstine testifies before the House Committee on Science, Space and Technology on April 2, 2019, during a hearing to review NASA's fiscal year 2020 budget request.

Bridenstine knows the perils of asteroid strikes all too well. In February 2013, he had been a Congressman in Oklahoma for just a month when a devastating asteroid streaked across the Russian sky.

Known as the Chelyabinsk Event, it was the largest known meteor strike in over a century and it injured more than 1,600 people. It "released the energy equivalent of around 440,000 tons of TNT," according to NASA.

"I wish I could tell you these events are exceptionally unique," Bridenstine said during the presentation, noting they have occurred three times in the past 100 years. "But they are not."

Currently, there are two asteroid-centric missions going on around the world — NASA's OSIRIS-REx probe, which reached the Bennu asteroid in December 2018, and the Japanese Hayabusa2 spacecraft, which recently "bombed" the Ryugu asteroid in an effort to learn more about it.

HOW AMERICA CAN GET ITS SLICE OF THE $1 TRILLION SPACE ECONOMY

Bridenstine highlighted the scientific importance of both of these missions but added that planetary defense is also an important component. "Yes, it's about science, it's about discovery, it's about exploration, but one of the reasons we do those missions is so that we can characterize those objects to protect, again, the only planet we know to host life."

"We have to use our systems, use our capabilities to ultimately get a lot more data, and we have to do it faster," Bridenstine said.

Planetary defense

When it comes to planetary defense, NASA is not sitting on its haunches, having taken several steps to protect Earth by detecting and tracking near-Earth Objects, also known as NEOs.

Last June, NASA unveiled a 20-page plan that details steps the U.S. should take to be better prepared for NEOs, asteroids and comets that come within 30 million miles of Earth. Lindley Johnson, the space agency's planetary defense officer, said at the time that the country "already has significant scientific, technical and operational capabilities" to help with NEOs, but implementing the new plan would "greatly increase our nation’s readiness and work with international partners to effectively respond should a new potential asteroid impact be detected.”

There are approximately 18,000 known NEOs and that number is constantly growing.

MYSTERIOUS INTERSTELLAR METEOR MAY HAVE SLAMMED INTO EARTH IN 2014

In 2016, NASA formalized the agency’s prior program for detecting and tracking NEOs and put it inside its Science Mission Directorate.

NASA will launch its first asteroid defense mission, the Double Asteroid Redirection Test (DART) mission, in 2022. Earlier this month, NASA awarded a $69 million contract to SpaceX, the space exploration company led by Elon Musk, to help with DART.

Currently, asteroid scientists from around the world are conducting a drill showing what the various global agencies would do about a potential asteroid collision. For the first time, the drill is being played out over social media. Updates of the hypothetical event are being shared on the ESA Operations Twitter account until May 3.

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2019-04-30 13:28:01Z
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Chronicles of the Rings: What Trees Tell Us - The New York Times

TUCSON — From the early 1700s until the 1960s, the fast moving river of wind known as the North Atlantic Jet Stream, which drives weather extremes over Europe, was pretty steady on its course.

Then it became less predictable. But instrument data alone can’t tell the jet stream’s movements for comparison over the centuries, given that scientists began keeping records of weather events via instruments only in the late 19th century.

The rings of trees, however, offer a far more complete historical picture of climate variations. As they age, trees grow outward from the center, and each year a new, distinct circle of dead wood is created around the trunk of most trees. In that ring, one can find information about precipitation, temperature and other data about that year.

Kiyomi Morino, a research associate at the Laboratory of Tree-Ring Research at the University of Arizona, during a field sampling on Mount Bigelow, in the Santa Catalina Mountains. CreditAdriana Zehbrauskas for The New York Times

A team led by Valerie Trouet, a dendrochronologist, sampled 400 trees from the Balkans and 200 in Scotland — including what might be the oldest known tree in Europe, a Bosnian pine in Greece named Adonis, which is 1,075 years old. The jet stream flows between these two regions, and trees revealed the range of temperatures in their rings and the frequency of fires over time, an expansive chronicling of jet stream behavior.

“More extreme positions create more extreme climate events, especially heat waves and storms,” in Europe, Dr. Trouet said. And the tree rings show “big fires happen in the Balkans when the jet is in its southerly position.”

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Holes in the trunk were made to extract samples from a tree on Mount Bigelow.CreditAdriana Zehbrauskas for The New York Times

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A sample from Siberia, with the core dating from 1637 and the outer ring from 2011, hangs on a wall at the research lab on the University of Arizona campus in Tucson.CreditAdriana Zehbrauskas for The New York Times

The fact that the stream has become more variable only in recent decades suggests that the shift is the result of humans’ effects on climate, Dr. Trouet said. “The recent rise in variance is unprecedented in 300 years,” she said. More analysis is underway to look back to even earlier centuries.

Reading the climate stories these trees tell will help with forecasting. “One of the big questions in the field is what’s going to happen to the jet stream,” said Dr. Trouet. “This data helps the modeling of climate change become more reliable.”

Trees, it seems, are giant organic recording devices that contain information about past climate, civilizations, ecosystems and even galactic events, much of it many thousands of years old.

In recent years, the techniques for extracting information from tree rings has been honed and expanded. New technologies and techniques are able to pry a much deeper and wider range of information out of trees.

The field “has exploded,” Edward Cook, director of the tree ring lab at Lamont-Doherty Earth Observatory, said.

The Laboratory of Tree-Ring Research here at the University of Arizona was founded in the 1930s by A.E. Douglass, an astronomer who turned to trees to better understand the connection between sunspots and climate.

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A tree core sample extracted by Mr. Morino.CreditAdriana Zehbrauskas for The New York Times

The lab has helped establish other labs around the world, which in turn has rapidly increased the number of studied trees. There are now roughly a dozen large labs globally and data from 4,000 sites on all continents except Antarctica. The information is stored in the International Tree Ring Data Bank, a library open to all researchers. As more tree data becomes available, a much richer picture forms of the nexus of past climate, ecosystems and human civilization.

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Some of the hundreds of thousands of samples in the archive at the Arizona tree ring lab.CreditAdriana Zehbrauskas for The New York Times

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France Conciatori, a visiting researcher, works on wood samples at the lab.CreditAdriana Zehbrauskas for The New York Times

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Micro tree samples.CreditAdriana Zehbrauskas for The New York Times

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Julia Podgorski working on a tree core sample.CreditAdriana Zehbrauskas for The New York Times

For its first 80 years, the lab was located in much smaller — and noisier — quarters under the University of Arizona football stadium. “If you worked on Saturdays you could hear people in the bleachers stamping their feet,” said Russell K. Monson, who studies plant physiology here.

In 2012, the lab moved into a larger building to accommodate its growing mission and number of researchers — now some 70 or so — and to unpack its vast collection of tree rings and core samples. There are now more than a half-million samples, from slivers to an enormous slice of giant sequoia in the lobby, a large enough table top, perhaps, to seat all of King Arthur’s knights. The building houses the world’s largest collection of tree ring samples.

The basement storage area resembles a coffee table wood shop, infused with the fragrant perfume of cut wood. Hundreds of two-inch-thick slices of large trees, their rich grains sanded and polished, are stacked on their sides.

The lab also houses a slice of the bristlecone pine that was cut down in the 1960s by a graduate student named Donald Rusk Currey from the University of North Carolina at Chapel Hill. It wasn’t until after he felled the tree and counted the rings that he realized, to his horror, that he had, with permission from the United States Forest Service, unceremoniously sawed down the oldest known tree in the world — a stately gnarled pine called Prometheus.

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Wood samples for research at the Laboratory of Tree Ring Research at the University of Arizona.CreditAdriana Zehbrauskas for The New York Times

Research involving tree rings is divided into three main categories — dendroclimatology, the analysis of tree rings for past climate data; dendroarchaeology, the study of tree rings to understand how past climate affected human societies; and dendroecology, which reconstructs past forest ecosystems. The most common tree rings studied come from bristlecone pine, fir and spruce.

At this particular time, the most essential role for tree rings is probably their use in reconstructing past climate and providing much greater context. “The instrumental period provides a snapshot,” of past climate, said David Meko, a researcher here, “but the tree rings are a panorama.”

This window into the deep climate past has become vital in a rapidly warming world, to show how the climate of the last half-century is far outside the historical norms going back thousands of years.

Living bristlecone pine trees, for example, are several thousand years old and their information is added to by those that died thousands of years ago, but remained intact in their cold, dry high-altitude environment.

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It’s hard to argue with tree rings that huge environmental changes are not occurring. Climate change seen in the past six or seven decades has few, if any, comparisons in the far past, researchers say.

The current two-decade-long drought on the Colorado River, for instance, is the longest since medieval times when a drought lasted for 62 years — with no very wet years in between dry years. An occasional very wet year can make a long drought more bearable.

Moreover, conditions in some recent years are the hottest and driest in many centuries. “We keep breaking records year after year,” Dr. Meko said. “It’s a little worrisome to see the most extreme years right near the present.”

Unprecedented hot droughts, like the current one, make a decline in precipitation even worse, by causing more evaporation. Officials along the Colorado River are deeply worried about the trend toward warmer temperatures and less precipitation and are preparing for a grim future without or with less river water — unthinkable just 20 years ago. (This year though, was an El Niño year, and the snowpack in the Colorado Rockies was well above average.)

To make matters worse, tree rings show that water in the Colorado River was apportioned to states based on flow from 1905 to 1922, some of the wettest years in the last 12 centuries, an era known as a pluvial period.

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Valerie Trouet, a dendrochronologist.CreditAdriana Zehbrauskas for The New York Times

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Bryan Black, dendrochronologist.CreditAdriana Zehbrauskas for The New York Times

Researchers can also look at snowpack in tree ring records. In 2015, in the Sierras the snowpack was the lowest in 500 years. This year may be one of the highest snowpacks in decades, a testament perhaps to climate whiplash. Researchers here are reconstructing snowpack data by examining tree ring records across the entire western United States for the last 2,000 years.

Trees hold other valuable information as well. Oxygen isotope analysis, for example, has unlocked the source of the water that a tree took up centuries ago and can determine whether it was from a hurricane or a severe thunderstorm.

Tree rings also provide a glimpse into the possible global impacts of geoengineering — a proposal to scatter aluminum sulfate into the atmosphere to block the sun and cool the planet, which some scientists have proposed as a solution to climate change.

“Volcanic eruptions are the best proxy of geoengineering,” Dr. Trouet said. Rings analyzed from trees in five locations around the world show that after a volcano erupted in 1568, the global climate cooled considerably for two years — evidenced in narrow tree rings — and the northern edge of the tropics receded as the planet cooled.

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Samples from the Black Mesa Navajo archaeological site at the lab.CreditAdriana Zehbrauskas for The New York Times

Those tree rings also showed that during six decades, from 1568 until 1634, there was, because of natural climate variation, six decades of expansion of the subtropics, which pushed desert climates north. Because of expanding zones of hot and dry weather, the Ottoman Empire in Turkey ended, the Ming dynasty collapsed and the Jamestown colony in Virginia was abandoned, suggesting, Dr. Trouet said, they were in part at least, climate-related. “The way society handles a drought politically is also part of the picture,” she said.

Other sources — lake sediments; ice core samples; coral; the otolith, or ear bone, of fish; and even the shells from living and long dead geoducks, a large bivalve with a snakelike appendage — add to the broader picture.

“We have divers sucking up ancient geoducks off the ocean floor,” said Bryan Black, a professor of dendrochronology who also specializes in marine organisms. Combined with long dead geoduck shells, data could go back many thousands of years. Shells from the coast of Iceland already go back 1,000 years. “They show that the last century is unprecedentedly warm,” Dr. Black said.

Experts are using the shell ring information, combined with tree ring data, to understand how climate drives ocean productivity and the species mix of fish, to assist fisheries managers. “The bottom line is to be aware of climate whiplash and what that means for fisheries,” Dr. Black said.

Even the stars give up some of their secrets to trees. The sun and other stars emit radiation called Galactic Cosmic Rays, or G.C.R.s, that react in the atmosphere with nitrogen and change the levels of carbon 14, which is taken up by every living thing and becomes a tracer for cosmic ray levels.

Past spikes in G.C.R.s from solar flares or other sources are largely a mystery, but have attracted keen interest from researchers, because if they occur now they could wipe out communication satellites and other technology. An event in 744, first found in Japanese cedar trees and since found globally, is the strongest cosmic ray event in the tree ring record, a magnitude larger than the Carrington event, a solar storm in 1859, and apparently noted by people alive at the time.

“This year also appeared in the heavens a red crucifix, after sunset,” was how the Anglo-Saxon Chronicles reported the event in the mid-eighth century.

It was most likely a huge solar flare. “It is unprecedented, there’s nothing else like it,” said Charlotte Pearson, a professor at the tree ring lab. “We’re trying to work out what it is and what caused it but we’re still not sure.”

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2019-04-30 06:30:14Z
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What if an asteroid was about to hit Earth? Scientists ponder question - Phys.org

A Nasamosaic image of asteroid Bennu, composed of 12 PolyCam images

Here's a hypothetical: a telescope detects an asteroid between 100 and 300 meters in diameter racing through our solar system at 14 kilometers per second, 57 million kilometers from Earth.

Astronomers estimate a one percent risk the space rock will collide with our planet on April 27, 2027. What should we do?

It's this potentially catastrophic scenario that 300 astronomers, scientists, engineers and emergency experts are applying their collective minds to this week in a Washington suburb, the fourth such international effort since 2013.

"We have to make sure people understand this is not about Hollywood," said NASA Administrator Jim Bridenstine as he opened the sixth International Planetary Defense Conference at the University of Maryland's campus in College Park.

Countries represented include China, France, Germany, Israel, Italy, Russia and the United States.

The idea that the planet Earth may one day have to defend itself against an asteroid used to elicit what experts call a "giggle factor."

But a meteor that blew up in the atmosphere over Russia on February 15, 2013, helped put an end to the sneers.

On that morning, a 65-foot (20-meter) asteroid appear out of nowhere over the southern Urals, exploding 14 miles (23 kilometers) above the town of Chelyabinsk with such force that it shattered the windows of thousands of buildings.

A thousand people were injured by the shards.

But "the positive aspect of Chelyabinsk is that it made the public aware, it made the political decision makers aware," Detlef Koschny, co-manager of the Planetary Defence Office of the European Space Agency (ESA) told AFP.

A meteorite trail is seen above a residential apartment block in the Urals city of Chelyabinsk, on February 15, 2013

How many?

Only those asteroids whose orbit around our Sun brings them within 31 million miles of our planet—defined as "near Earth"—are of interest.

Astronomers are finding new ones each day: more than 700 so far this year, for a total of 20,001, said Lindley Johnson of NASA's Planetary Defense Coordination Office, which was created in 2016.

Among the most risky is a rock named 2000SG344: 165 feet in diameter, with a one in 2,096 chance in striking the Earth within a hundred years, according to the ESA.

The majority are very small, but 942 are more than 0.6 miles across, estimates astronomer Alan Harris.

The scientist told an audience that some large ones are probably still out there: "A fair fraction of the biggest ones are hiding... basically parked behind the Sun."

They are found mainly by two US telescopes, one in Arizona and the other in Hawaii.

The ESA has built a telescope for this purpose in Spain and is planning others in Chile and Sicily.

Many astronomers are demanding a space telescope because terrestrial telescopes are unable to detect objects on the other side of the Sun.

A view of the facade of a local paint and varnish plant damaged by a shockwave from a meteor in the Urals city of Chelyabinsk on February 15, 2013

Deflecting an asteroid

This week's exercise seeks to simulate global response to a catastrophic meteorite. The first step is aiming telescopes at the threat to precisely calculate its speed and trajectory, following rough initial estimates.

Then it boils down to two choices: try to deflect the object, or evacuate.

If it is less than 165 feet, the international consensus is to evacuate the threatened region. According to Koschny, it is possible to predict the country it will strike two weeks ahead. Days away from impact, it can be narrowed down to within hundreds of kilometers.

What about bigger objects? Trying to nuke them to smithereens like in the movie Armageddon would be bad idea, because it could just create smaller but still dangerous pieces.

The plan, instead, is to launch a device toward the asteroid to divert its trajectory—like a cosmic bumper car.

NASA plans to test this idea out on a real asteroid 492 feet across, in 2022, with the Double Asteroid Redirection Test (DART) mission.

One issue that remains is politics, says Romana Kofler, of the United Nations Office for Outer Space Affairs.

"Who would be the decision making authority?" she asked. "The consensus was to leave this aspect out."

The United Nations Security Council would likely be convened, but it's an open question as to whether rich countries would finance an operation if they themselves weren't in the sights of 2000SG344 or another celestial rock.

Explore further

The day the asteroid might hit

Citation: What if an asteroid was about to hit Earth? Scientists ponder question (2019, April 30) retrieved 30 April 2019 from https://phys.org/news/2019-04-asteroid-earth-scientists-ponder.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

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2019-04-30 07:15:51Z
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'These events are not rare': NASA exercise highlights existential threat of asteroid impacting Earth - New Zealand Herald

It's the doomsday scenario fit for a Hollywood blockbuster — and NASA scientists are about to see it go down.

This week researchers will run an exercise at the 2019 Planetary Defence Conference that will play out a "realistic scenario" of an asteroid flying through space on an impact trajectory with Earth, reports news.com.au

NASA's Planetary Defence Co-ordination Office (PDCO) is running the simulation exercise as part of a recently announced federal "action plan" for defending our planet against asteroid impact.

The hypothetical asteroid is thought to be about 100 to 300 metres in size and only has a very small likelihood of smashing into Earth on April 29, 2027, according to a NASA web page dedicated to the highly detailed scenario.

Global astronomers are always on the lookout for near-Earth objects (NEOs), which are classified as asteroids and comets that orbit the Sun and come within 50 million kilometres of Earth's orbit.

Along with the NASA unit, the European Space Agency's Space Situational Awareness-NEO Segment and the International Asteroid Warning Network (IAWN) are tasked with hunting the skies for potentially dangerous space rocks.

These "tabletop exercises" are not uncommon and are about walking through the steps that will need to be taken along with governments and emergency agencies to mitigate the risk to society should the unthinkable happen.

"These exercises have really helped us in the planetary defence community to understand what our colleagues on the disaster management side need to know," said Lindley Johnson, NASA's planetary defence officer. "This exercise will help us develop more effective communications with each other and with our governments."

NASA has been tasked with the goal of identifying and tracking 90 per cent of near-Earth meteors that are larger than 140 metres by the year 2020. But the task could end up taking nearly three decades, experts claim. And even then we're far from protected.

Last month, it was revealed a relatively small and undetected meteor blew up over the Bering Sea, off Russia's Kamchatka Peninsula on December 18. The explosion — which happened 25.6 kilometres above the Earth's surface — released 10 times the energy produced by the atomic bomb dropped on Hiroshima in World War II.

Six years ago, a meteor exploded over the Russian city of Chelyabinsk and released a shockwave that shattered thousands of windows and injured more than 1600 people. That meteor was only 19 metres wide.

A meteor streaks through the sky over Chelyabinsk, Russia, in 2013. Photo / AP

"The thing is the one over Chelyabinsk and this latest one (in December) are about 10 times smaller" that the ones targeted by the NASA mandate, astronomer Alan Duffy explained to news.com.au last month. "It's far harder to detect those, and we still haven't found all the larger asteroids yet."

He has called for more funding to be allocated to monitoring systems, asserting "it is just a matter of time before one of these blasts occur over a city and cause incredible damage".

During a keynote address at the opening of the Planetary Defence Conference, NASA administrator Jim Bridenstine warned preparing for an asteroid impact is something that needs to be taken very seriously.

"We have to make sure that people understand that this is not about Hollywood, it's not about movies. This is about ultimately protecting the only planet we know, right now, to host life, and that is the planet Earth," he said.
"These events are not rare, they happen."

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2019-04-30 06:24:32Z
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SpaceX resupply launch delayed by malfunction on space station - Spaceflight Now

A portion of a solar array wing on the International Space Station is visible in this image. Credit: NASA

A SpaceX Dragon supply ship packed with nearly three tons of experiments, crew provisions and supplies will remain on the ground until at least Friday morning to allow more time for NASA flight controllers to troubleshoot a problem with an electrical distribution unit on the International Space Station.

Multiple sources said the commercial resupply launch, previously scheduled for Wednesday, will be pushed back at least two days to no earlier than Friday at 3:11 a.m. EDT (0711 GMT).

The delay will allow time for NASA flight controllers at the Johnson Space Center in Houston to continue troubleshooting an issue with a distribution box in the space station’s electrical power system. Engineers detected an issue with the Main Bus Switching Unit on Monday morning, and ground teams may elect to replace the component later this week, ahead of the SpaceX cargo launch.

The unit is one of several that routes power from the space station’s U.S. solar arrays to the research outpost’s electrical channels. The suspect unit distributes power to two of the eight electrical channels on the station, including a power supply for the space station’s robotic arm, which the station astronauts will use to capture the Dragon cargo craft as it approaches the complex.

While the robotic arm remains powered through a separate channel, NASA flight rules require redundant power supplies for the arm during critical operations, such as the grapple of a free-flying spacecraft.

Ground teams have replaced a failed Main Bus Switching Unit using the station’s robotic arm before. The capability to robotically replace the power distribution box means astronauts may not have to conduct a spacewalk for the task.

The electrical system glitch does not pose any immediate concern to the station or its six-person crew, NASA said.

NASA’s Orbiting Carbon Observatory-3 (OCO-3) and the U.S. military’s Space Test Program-Houston 6 (STP-H6) payloads are in view installed in the trunk of SpaceX’s Dragon spacecraft inside the SpaceX facility at NASA’s Kennedy Space Center in Florida on March 23, 2019. Credit: NASA

“Monday morning, teams identified an issue with the International Space Station’s electrical power system and are working to identify the root cause and restore full power to the system,” the space agency said in an updated posted on its website.

In the update posted Monday afternoon, officials said engineers were examining an unspecified issue with a Main Bus Switching Unit.

“Flight controllers have been working to route power through the remaining six power channels,” NASA said. “Electrical power generated by the station’s solar arrays is fed to all station systems through these power channels.”

NASA said Monday afternoon that managers were discussing how the power system problem might impact plans for the SpaceX resupply launch.

If the Dragon spacecraft had launched Wednesday, it was due to arrive at the station early Saturday. Assuming a launch from Cape Canaveral on Friday morning, the Dragon cargo freighter is scheduled to reach the complex early Sunday.

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Follow Stephen Clark on Twitter: @StephenClark1.

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2019-04-30 05:59:21Z
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Senin, 29 April 2019

What if a killer asteroid were headed toward Earth? NASA plans to find out this week - NBC News

April 29, 2019, 4:00 PM UTC

By David Freeman

Think of it as a crash course in averting asteroid crashes.

As part of the 2019 Planetary Defense Conference, NASA, the Federal Emergency Management Agency and their international partners will conduct a so-called tabletop exercise designed to show how they would react to the discovery of a fictional asteroid heading our way.

The exercise is being conducted as part of a federal "action plan" for defending Earth against asteroids that was announced last June. It will play out over the five days of the conference, which begins in College Park, Maryland, on Monday and runs through May 3. You can watch it live in the player below.

"Exercises like this have been run at several conferences over the years, and government agencies have also had them," Andrew Rivkin, a planetary astronomer at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and an expert on asteroids, told NBC News MACH in an email. "It's definitely worth doing, if only so people are aware of the issues and how complex some of them are."

Rivkin, who said he was participating in the exercise, likened it to a fire drill but added that the consequences of a major asteroid strike "could be very bad (just ask the dinosaurs)," referring to the impact of a six-mile-wide asteroid that is believed to have caused the dinosaurs' demise some 65 million years ago.

According to the loosely scripted scenario, astronomers discover that a make-believe space rock dubbed 2019 PDC has a one-in-100 chance of smashing into Earth in 2027. Participants in the exercise, including the European Space Agency and the International Asteroid Warning Network, as well as NASA and FEMA, will consider how they might mount space missions to investigate and possibly deflect the asteroid — and how the effects of an impact might be mitigated.

Even though 2019 PDC is fictitious, the threat posed by asteroid strikes is all too real. As of the start of 2019, more than 19,000 near-Earth objects (NEOs) had been discovered — and 30 more are discovered each week as astronomers continue to search for them.

"We've only found about one-third of NEOs large enough to cause severe regional damage, so we have a lot of work left to do," Amy Mainzer, an astronomer and asteroid expert at NASA's Jet Propulsion Laboratory in Pasadena, California, said in an email. "We need to build and operate more capable space- and ground-based telescopes, in my opinion," she added.

The animation depicts a mapping of the positions of known near-Earth objects (NEOs) at points in time over the past 20 years. There are more than 18,000 known NEOs, with new ones being discovered at the rate of about 40 per week.NASA/JPL-Caltech

So far, experts haven't identified any large objects on a collision course with Earth.

"We are confident that searches have found anything big enough to be a worldwide problem," Rivkin said in the email. "The space agencies of the world are working together to complete the search programs to make sure the neighborhood is safe, and NASA is planning a mission called DART [for Double Asteroid Redirection Test] to practice deflecting an asteroid just in case we ever need to do so. We don't anticipate having to do so any time in the foreseeable future, but it's good to be prepared!"

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2019-04-29 16:00:00Z
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Scientists find ‘alien’ grain of dust in Antarctica that could challenge our understanding of the solar system - The Independent

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https://www.independent.co.uk/life-style/gadgets-and-tech/news/alien-grain-of-dust-antarctica-solar-system-life-a8891486.html

2019-04-29 15:00:48Z
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Weird Black Hole Is Shooting Out Wobbly Jets Because It's Dragging Spacetime - ScienceAlert

Some 7,800 light-years away, in the constellation of Cygnus, lies a most peculiar black hole. It's called V404 Cygni, and in 2015, telescopes around the world stared in wonder as it woke from dormancy to devour material from a star over the course of a week.

That one event provided such a wealth of information that astronomers are still analysing it. And they have just discovered an amazing occurrence: relativistic jets wobbling so fast their change in direction can be seen in mere minutes.

And, as they do so, they puff out high-speed clouds of plasma.

"This is one of the most extraordinary black hole systems I've ever come across," said astrophysicist James Miller-Jones of the International Centre for Radio Astronomy Research (ICRAR) at Curtin University in Australia.

V404 Cygni is a binary microquasar system consisting of a black hole about nine times the mass of the Sun and a companion star, an early red giant slightly smaller than the Sun.

The black hole is slowly devouring the red giant; the material siphoned away from the star is orbiting the black hole in the form of an accretion disc, a bit like water circling a drain. The closest regions of the disc are incredibly dense and hot, and extremely radiant; and, as the black hole feeds, it shoots out powerful jets of plasma, presumably from its poles.

Scientists don't know the precise mechanism behind jet production. They think material from the innermost rim of the accretion disc is funnelled along the black hole's magnetic field lines, which act as a synchrotron to accelerate the particles before launching them at tremendous velocities.

But V404 Cygni's wobbly jets, shooting out in different directions at different times, on such rapidly changing timescales, and at velocities up to 60 percent of the speed of light, are in a class of their own.

"We think the disc of material and the black hole are misaligned," Miller-Jones said. "This appears to be causing the inner part of the disc to wobble like a spinning top and fire jets out in different directions as it changes orientation."

[embedded content]

It's a bit like a spinning top that starts to wobble as it's slowing down, the researchers said. This change in the rotational axis of a spinning body is called precession. In this particular instance, we have a handy explanation for it courtesy of Albert Einstein.

In his theory of general relativity, Einstein predicted an effect called frame-dragging. As it spins, a rotating black hole's gravitational field is so intense that it essentially drags spacetime with it. (This is one of the effects scientists hoped to observe when they took a picture of Pōwehi.)

In the case of V404 Cygni, the accretion disc is about 10 million kilometres (6.2 million miles) across. The misalignment of the black hole's rotational axis with the accretion disc has warped the inner few thousand kilometres of said disc.

The frame-dragging effect then pulls the warped part of the disc along with the black hole's rotation, which sends the jet careening off in all directions. In addition, that inner section of the accretion disc is puffed up like a solid doughnut that also precesses.

"This is the only mechanism we can think of that can explain the rapid precession we see in V404 Cygni," Miller-Jones said.

It's so fast that the usual method radio telescopes use for imaging space were practically useless. Usually, these devices rely on long exposures, observing a region for several hours at a time, moving across the sky to track their target. But in this case, the method produced images too blurred to be of use.

So the team had to use a different method, taking 103 separate images with exposure times of just 70 seconds and stitching them together to create a movie - and sure enough, there were the wibbly wobbly spacetimey jets.

"We were gobsmacked by what we saw in this system - it was completely unexpected," said physicist Greg Sivakoff of the University of Alberta.

"Finding this astronomical first has deepened our understanding of how black holes and galaxy formation can work. It tells us a little more about that big question: 'How did we get here?'"

The research has been published in Nature.

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2019-04-29 15:18:21Z
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Asteroid collision impact drill set for this week - Fox News

World governments have been concerned for decades about a potential asteroid collision and the chaos that would ensue upon Earth. Now, the actions of what agencies around the world would do about it are being shared with the public for the first time ever on social media.

Though the drill is run every two years by asteroid scientists around the world, the European Space Agency has decided to share the event publicly so everyone can see what would happen and what actions might be taken to mitigate the damage.

“The first step in protecting our planet is knowing what’s out there,” says Rüdiger Jehn, ESA’s Head of Planetary Defense, in a statement. “Only then, with enough warning, can we take the steps needed to prevent an asteroid strike altogether, or to minimize the damage it does on the ground.”

Graphic showing the hypothetical impact risk corrdior of asteroid 2019 PDC, when its orbit is still not fully known. (Credit: Google Earth, ESA)

ELON MUSK IS GOING TO HELP NASA SAVE EARTH FROM AN ASTEROID COLLISION

Updates from the drill will be shared on the ESA Operations Twitter account, starting Monday, April 29 and running until May 3.

The first tweet has already been written, with the ESA writing: "A hypothetical asteroid has been 'discovered', and worryingly looks set to impact Earth. Follow the progress of fictional asteroid #2019PDC and the response on the ground, over the next few days of the #PlanetaryDefense Conference. #FictionalEvent🌍☄️"

The asteroid scientists who take part in the drill are doing so as part of the 2019 Planetary Defense Conference, which is put on by NASA's Planetary Defense Coordination Office and the U.S. Federal Emergency Management Agency. The scientists will be assigned different roles, such as "space agency," "astronomer" or "national government," and will work off what each other is doing, the ESA added in the statement.

In 2016, NASA formalized the agency’s prior program for detecting and tracking near-Earth Objects (NEOs) and put it inside its Science Mission Directorate.

Though there are 20,000 asteroids (and counting) whose orbit brings them near Earth, NASA has been expanding its protocols for how to take action from a potential collision.

HOW AMERICA CAN GET ITS SLICE OF THE $1 TRILLION SPACE ECONOMY

Last June, NASA unveiled a 20-page plan that details steps the U.S. should take to be better prepared for NEOs such as asteroids and comets that come within 30 million miles of the planet.

Lindley Johnson, the space agency's planetary defense officer, said at the time that the country "already has significant scientific, technical and operational capabilities" to help with NEOs, but implementing the new plan would "greatly increase our nation’s readiness and work with international partners to effectively respond should a new potential asteroid impact be detected.”

In addition to enhancing NEO detection, tracking and characterizing capabilities and improving modeling prediction, the plan also aims to develop technologies for deflecting NEOs, increasing international cooperation and establishing new NEO impact emergency procedures and action protocols.

ANCIENT ASTEROID STRIKES ON MARS MAY HAVE 'PRODUCED KEY INGREDIENTS FOR LIFE'

Earlier this month, NASA awarded a $69 million contract to SpaceX, the space exploration company led by Elon Musk, to help it with asteroid deflection via its Double Asteroid Redirection Test (DART) mission.

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2019-04-29 13:43:32Z
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SpaceX readies for early morning launch Wednesday at Cape Canaveral - WFTV Orlando

CAPE CANAVERAL, Fla. - SpaceX is planning to launch thousands of pounds of supplies, research equipment and hardware to the International Space Station early Wednesday.

The launch announcement comes after SpaceX completed a static fire test of its Falcon 9 rocket on Saturday.

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The rocket is set to blast off at Space Launch Complex 40 at Cape Canaveral Air Force Station at 3:59 a.m.

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This launch will mark SpaceX’s 17th mission under NASA's Commercial Resupply Services contract to send cargo to the International Space Station.

WFTV will share coverage of the launch if it happens on Wednesday on Eyewitness News This Morning.

Launch Update 🚀 NASA and SpaceX are now targeting Wednesday, May 1 at 3:59 a.m. EDT for the #CRS17 mission. https://t.co/wq9zJiTfMH pic.twitter.com/39dpJdtzwR
— Kennedy Space Center Visitor Complex (@ExploreSpaceKSC) April 27, 2019

.@SpaceX is now targeting May 1 at 3:59am ET for the next cargo launch to the @Space_Station. Onboard will be more than 5,500 pounds of @ISS_Research, supplies and hardware for crew members living and working on our orbiting outpost. Details: https://t.co/u61I4ZUXKJ pic.twitter.com/XadASrEpxf
— NASA (@NASA) April 27, 2019

Static fire test of Falcon 9 complete—targeting May 1 launch from Pad 40 in Florida for Dragon’s seventeenth mission to the @Space_Station
— SpaceX (@SpaceX) April 27, 2019

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2019-04-28 22:41:15Z
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Minggu, 28 April 2019

The day the asteroid might hit - EarthSky

Line drawing of asteroid orbit in the inner solar system.

Hypothetical orbit for fictional asteroid 2019 PDC, via ESA.

The European Space Agency (ESA) said late last week it’ll be tweeting coverage of a major international asteroid impact exercise live via social media from April 29 to May 3, 2019. You can follow the coverage via the @esaoperations Twitter channel. It’s a drill – much like the tornado drills some of us underwent in elementary school – but in this case conducted by scientists, space agencies and civil protection organizations, all acting as if an asteroid is headed for an impact with Earth. This exercise – simulating a fictional, but plausible, imminent asteroid impact – is conducted every two years by asteroid experts across the globe. It’s being conducted from the Planetary Defense Conference in Washington, D.C. ESA said:

During the week-long scenario, participants – playing roles such as ‘national government’, ‘space agency’, ‘astronomer’ and ‘civil protection office’ – don’t know how the situation will evolve from one day to the next, and must make plans based on the daily updates they are given.

Follow the live coverage April 29 to May 3 via @esaoperations on Twitter

You can also participate, in a more limited way, via ESA’s Facebook page. It will host two livestream videos straight from the Planetary Defense Conference. The first will be today (Sunday, April 28) at 12 UTC (14 CEST, 8 a.m. EDT; translate UTC to your time) with Rüdiger Jehn, ESA’s Head of Planetary Defense. The second will be Thursday, May 2, at around mid-afternoon European time.

Check out livestream videos from the Planetary Defense Conference via ESA’s Facebook page

For daily updates on the asteroid impact scenario, check out “Rolling coverage: Brace for hypothetical asteroid impact,” beginning on the first day of the conference, Monday, April 29.

Follow ESA’s rolling coverage: Daily updates on the asteroid impact scenario.

Find out how this dramatic & risky situation will turn out LIVE from this year's #PlanetaryDefense Conference, starting Monday, 29.04. During the week, we'll post live updates the moment the experts are informed. What will they decide? #FICTIONALEVENT #ItHappenedBefore pic.twitter.com/3y7WTXlOyK

— ESA Operations (@esaoperations) April 26, 2019

This year’s hypothetical asteroid has been given the label ‘2019 PDC’. NOTE: Although realistic, all “objects” and “events” described below are completely fictional and do NOT describe an actual asteroid impact. ESA described the fictional scenario this way:

— An asteroid was discovered on March 26 2019, and has been given the name 2019 PDC by the International Astronomical Union‘s (IAU) Minor Planet Center.

— Initial calculations suggest the orbit of 2019 PDC will bring it within 7.5 million km [4.6 million miles] of Earth’s orbit. (Or, within 0.05 AU of Earth’s orbit).

.— 2019 PDC is travelling in an eccentric orbit, extending 2.94 AU at its farthest point from the sun (in the middle of the main asteroid belt), and 0.94 AU at its closest. It completes one full orbit around the sun every 971 days (2.66 years). See its orbit in more detail here.

— The day after 2019 PDC is discovered, ESA and NASA’s impact monitoring systems identify several future dates when the asteroid could hit Earth. Both systems agree that the asteroid is most likely to strike on April 29, 2027 – more than eight years away – with a very low probability of impact of about 1 in 50,000.

— When it was first detected, asteroid 2019 PDC was about 57 million km [35.4 million miles] from Earth, equal to 0.38 astronomical units [0.38 of the average Earth-sun distance]. It was travelling about 14 km/s [8.7 miles/sec], and slowly getting brighter.

— As observations continue, the likelihood of an impact in 2027 increases. Three weeks after discovery, after observations were paused during the full moon (and reduced visibility), the chance of impact has risen to 0.4 percent – that’s a chance of 1 in 250.

View larger. | Graphic showing the hypothetical impact risk corridor of hypothetical asteroid 2019 PDC, when its orbit is still not fully known. ESA said: “The asteroid’s uncertainty region at the time of the potential impact is much longer than the diameter of the Earth, but its width is only about 70 kilometers (45 miles). The intersection of the uncertainty region with the Earth creates a so-called ‘risk corridor’ across the surface of the Earth. The corridor wraps more than halfway around the globe, spanning from Hawaii on the western end, across the U.S. and Atlantic Ocean, and all the way to central and southern Africa on the eastern end. The red dots on the Google Earth image trace the risk corridor.” Image via ESA.

— Very little is known about the asteroid’s physical properties. From its brightness, experts determine that the asteroid’s mean size could be anywhere from 100-300 meters [approximately 300 to 1,000 feet].

— Asteroid 2019 PDC continued to approach Earth for more than a month after discovery, reaching its closest point on May 13. Unfortunately, the asteroid was too far away to be detected, and it is not expected to pass close to Earth until 2027 – the year of impact.

— As astronomers continued to track 2019 PDC, the chance of impact continued to rise. By April 2019, the first day of the Planetary Defence Conference, the probability of impact will have risen to 1 in 100.

This exercise is being produced by experts from NASA’s Planetary Defense Coordination Office working together with the U.S. Federal Emergency Management Agency (FEMA) at the 2019 Planetary Defense Conference, Washington, D.C. The conference is strongly supported by ESA, NASA and other agencies, organizations and scientific institutions.

Follow the live tweets April 29 to May 3 via @esaoperations on Twitter

Check out livestream videos from the Planetary Defense Conference via ESA’s Facebook page

Follow ESA’s rolling coverage: Daily updates on the asteroid impact scenario.

Bottom line: At the Planetary Defense Conference in Washington, D.C. – April 29 to May 3, 2019 – scientists, space agencies and civil protection organizations will be acting as if an asteroid is headed for an impact with Earth. This exercise – simulating a fictional but plausible imminent asteroid impact – is conducted every two years by these asteroid experts. This story tells how to follow the exercise on social media.

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https://earthsky.org/human-world/esa-social-media-hypothetical-impact-scenario-pdc

2019-04-28 11:48:45Z
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Selasa, 30 April 2019

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