NASA Unveils Program Aimed At Preventing An Asteroid Apocalypse

Among Earth's natural disasters-hurricanes, floods, earthquakes-the one humans probably ponder least is asteroids, huge objects zipping through our solar system at ludicrous speeds.

Federal officials call an asteroid or comet collision "low probability but high consequence," NASA-speak for it will probably never happen, but if it does we're toast. With that in mind, the U.S. and other nations have long sought to track such "near-Earth objects," or NEOs, coordinating efforts through the International Asteroid Warning Network and the United Nations.

The Trump administration now wants to enhance those efforts to detect and track potential planet killers, and to develop more capable means to deflect any that appear to be on a collision course.

"Fortunately, this type of destructive event is extremely rare," said Aaron Miles, an official with the White House Office of Science and Technology Policy. But just to be safe, the government unveiled new goals this week for NASA's work on countering NEOs over the next decade. If you're envisioning Bruce Willis or humming an Aerosmith song, please stop. This is serious.

More than 300,000 objects larger than 40 meters (131 feet) wide orbit the sun as NEOs, according to NASA estimates, with many being difficult to detect more than a few days in advance. Forty meters is about the average size an object must be to make it through the atmosphere without burning up; thousands of much-smaller meteors disintegrate harmlessly each day far above the planet. The meteor that injured more than 1,000 people in Chelyabinsk, Russia in February 2013, mainly by glass shattered from the shock wave of its explosion, was believed to be about 20 meters wide (65 feet).

The most recent encounter with an asteroid was on June 2, when a 2-meter boulder dubbed 2018 LA entered the atmosphere at 10 miles per second (38,000 mph) and exploded over Botswana.

OK, now here's the good news: NASA has documented roughly 96 percent of the objects large enough to cause a global catastrophe since work began in 1998, said Lindley Johnson, planetary defense officer at NASA's Planetary Defense Coordination Office. On Thursday alone, five massive asteroids zipped within 4.6 million miles of Earth-which is pretty close in space-including one called 2017 YE5, a 1,600-foot wide behemoth that, if it paid us a visit, would ruin everyone's day. But NASA has its number.

Also good news: This growing catalog of potentially Armageddon-causing (don't do it-the movie was terrible) objects offers the world years of notice about when an orbit would intercept Earth, given the immense distances asteroids and comets travel through space. For example, 101955 Bennu, a 1,600-foot wide carbon asteroid found in 1999 and which figures prominently in NASA's current deep-space research, has only a 1-in-24,000 chance of hitting Earth-and that's 157 years from now.

Today, NASA's catalog contains 18,310 NEOs, with about 8,000 of them classified as 140 meters wide and larger. That's the size at which enormous regional impacts and mass casualties would occur if one hit. How government agencies would prepare for such a calamity is a novelty to most.

"One of the key things we're finding is that, for emergency managers, this is so different we have to first educate them," said Leviticus Lewis, a response coordinator with the Federal Emergency Management Agency.

Now, more bad news: A chance remains that large comets from the outer solar system could suddenly appear and hit Earth with only a few months' warning. There's also the potential for a surprise from deep space-an object whose orbit isn't bound by the sun-like the kind that showed up last October. That's when Oumuamua, a 400-meter, cigar-shaped oddity, whizzed past the sun at almost 200,000 mph. The intriguing object was the first known to have come from interstellar space, to which it is now returning.

So can we do anything? NASA has devised three strategies for potentially sparing Earth annihilation by asteroid, with each method's effectiveness determined by the size and composition of an asteroid and how much warning there is.

Kinetic impact: A direct hit with a spacecraft to produce even a miniscule nudge may be sufficient if the asteroid has millions of miles yet to travel before it strikes the planet. Gravity: Attaching a spacecraft to an asteroid-what NASA dubs a "gravity tractor"-would alter its path because of the enlarged mass. And landing on a NEO is well within science's current toolbox: The European Space Agency landed on a comet four years ago, and Japan's Hayabusa 2 spacecraft is nearing an asteroid called Ryuga this month. NASA plans a similar rendezvous in December with Bennu. The downside-an asteroid can't be larger than 100 meters wide or this technique won't work. Nuke it: No, not like the movie. A nuclear explosion on a massive asteroid would superheat the surface and cause some of the mass to slough off, Johnson said on a call June 20 with reporters. A rocket could then theoretically push the asteroid to a different trajectory. This option, however, works only for a large body of which scientists have at least a decade's notice.

The Obama and Trump administrations have both sought more funds for asteroid research, with the annual budget jumping from $12 million to $150 million in this administration's most recent request.

Most of that funding is for NASA to complete its Double Asteroid Redirection Test (DART) mission in 2021-22. The goal is to impact the smaller "moonlet" of a binary asteroid called Didymos, to learn how well we may be able to alter the course of a future killer rock.

If successful, then mankind will know it has a viable option, if someday we see something headed our way.

The true power of the solar wind

The planets and moons of our solar system are continuously being bombarded by particles hurled away from the sun. On Earth this has hardly any effect, apart from the fascinating northern lights, because the dense atmosphere and the magnetic field of the Earth protect us from these solar wind particles. But on the Moon or on Mercury things are different: There, the uppermost layer of rock is gradually eroded by the impact of sun particles.

New results of the TU Wien now show that previous models of this process are incomplete. The effects of solar wind bombardment are in some cases much more drastic than previously thought. These findings are important for the ESA mission BepiColombo, Europe's first Mercury mission. The results have now been published in the planetology journal Icarus.

An Exosphere of Shattered Rock

"The solar wind consists of charged particles - mainly hydrogen and helium ions, but heavier atoms up to iron also play a role," explains Prof. Friedrich Aumayr from the Institute of Applied Physics at TU Wien. These particles hit the surface rocks at a speed of 400 to 800 km per second and the impact can eject numerous other atoms. These particles can rise high before they fall back to the surface, creating an "exosphere" around the Moon or Mercury - an extremely thin atmosphere of atoms sputtered from the surface rocks by solar wind bombardment.

This exosphere is of great interest for space research because its composition allows scientists to deduce the chemical composition of the rock surface - and it is much easier to analyse the exosphere than to land a spacecraft on the surface. In October 2018, ESA will send the BepiColombo probe to Mercury, which is to obtain information about the geological and chemical properties of Mercury from the composition of the exosphere.

Charge matters

However, this requires a precise understanding of the effects of the solar wind on the rock surfaces, and this is precisely where decisive gaps in knowledge still exist. Therefore, the TU Wien investigated the effect of ion bombardment on wollastonite, a typical moon rock. "Up to now it was assumed that the kinetic energy of the fast particles is primarily responsible for atomization of the rock surface," says Paul Szabo, PhD student in Friedrich Aumayr's team and first author of the current publication. "But this is only half the truth: we were able to show that the high electrical charge of the particles plays a decisive role. It is the reason that the particles on the surface can do much more damage than previously thought."

When the particles of the solar wind are multiply charged, i.e. when they lack several electrons, they carry a large amount of energy which is released in a flash on impact. "If this is not taken into account, the effects of the solar wind on various rocks are misjudged," says Paul Szabo. Therefore, it is not possible to draw exact conclusions about the surface rocks with an incorrect model from the composition of the exosphere.

Protons make up by far the largest part of the solar wind, and so it was previously thought that they had the strongest influence on the rock. But as it turns out, helium actually plays the main role because, unlike protons, it can be charged twice as positively. And the contribution of heavier ions with an even greater electrical charge must not be neglected either. A cooperation of different research groups was necessary for these findings: High-precision measurements were carried out with a specifically developed microbalance at the Institute of Applied Physics. At the Vienna Scientific Cluster VSC-3 complex computer simulations with codes developed for nuclear fusion research were carried out in order to be able to interpret the results correctly. The Analytical Instrumentation Center and the Institute for Chemical Technologies and Analytics of the TU Vienna also made important contributions.

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Cooperation partners of the research project were also the Physics Institute of the University of Bern and the Space Institute of the Austrian Academy of Sciences in Graz, which will now help contributing the new findings to the analysis of the forthcoming ESA space mission.

Under pressure: Extreme atmosphere stripping may limit exoplanets' habitability

New models of massive stellar eruptions hint at an extra layer of complexity when considering whether an exoplanet may be habitable or not. Models developed for our own Sun have now been applied to cool stars favoured by exoplanet hunters, in research presented by Dr Christina Kay, of the NASA Goddard Flight Center, on Monday 3rd July at the National Astronomy Meeting at the University of Hull.

Coronal mass ejections (CMEs) are huge explosions of plasma and magnetic field that routinely erupt from the Sun and other stars. They are a fundamental factor in so called "space weather," and are already known to potentially disrupt satellites and other electronic equipment on Earth. However, scientists have shown that the effects of space weather may also have a significant impact on the potential habitability of planets around cool, low mass stars -- a popular target in the search for Earth-like exoplanets.

Traditionally an exoplanet is considered "habitable" if its orbit corresponds to a temperature where liquid water can exist. Low mass stars are cooler, and therefore should have habitable zones much closer in to the star than in our own solar system, but their CMEs should be much stronger due to their enhanced magnetic fields.

When a CME impacts a planet, it compresses the planet's magnetosphere, a protective magnetic bubble shielding the planet. Extreme CMEs can exert enough pressure to shrink a magnetosphere so much that it exposes a planet's atmosphere, which can then be swept away from the planet. This could in turn leave the planetary surface and any potential developing lifeforms exposed to harmful X-rays from the nearby host star.

The team built on recent work done at Boston University, taking information about CMEs in our own solar system and applying it to a cool star system.

"We figured that the CMEs would be more powerful and more frequent than solar CMEs, but what was unexpected was where the CMEs ended up" said Christina Kay, who led the research during her PhD work.

The team modelled the trajectory of theoretical CMEs from the cool star V374 Pegasi and found that the strong magnetic fields of the star push most CMEs down to the Astrophysical Current Sheet (ACS), the surface corresponding to the minimum magnetic field strength at each distance, where they remain trapped.

"While these cool stars may be the most abundant, and seem to offer the best prospects for finding life elsewhere, we find that they can be a lot more dangerous to live around due to their CMEs" said Marc Kornbleuth, a graduate student involved in the project.

The results suggest that an exoplanet would need a magnetic field ten to several thousand times that of Earth's to shield their atmosphere from the cool star's CMEs. As many as five impacts a day could occur for planets near the ACS, but the rate decreases to one every other day for planets with an inclined orbit.

Merav Opher, who advised the work, commented, "This work is pioneering in the sense that we are just now starting to explore space weather effects on exoplanets, which will have to be taken into account when discussing the habitability of planets near very active stars."

NASA's Cassini Spacecraft Captures Stunning Photos of Saturn's Changing Seasons

NASA's Cassini spacecraft made new pictures of Saturn and the famous storm at its north pole on the second day of the planet's solstice, NASA reported.

Cassini observed how a huge storm has appeared and encircled Saturn over the last seven years of its mission. Scientists believe that such storms are influenced by seasonal effects of sunlight on Saturn's atmosphere.

"Reaching the solstice, and observing seasonal changes in the Saturn system along the way was a primary goal of Cassini's Solstice Mission," NASA's website reported.

Saturn's north-polar region in June 2013 and April 2017
Saturn's north-polar region in June 2013 and April 2017 / © Photo: NASA/JPL-Caltech/Space Science Institute/Hampton University

Basically, the spacecraft was able to follow the complete change of all seasons on Saturn, with the whole planet's system dramatically changing with the start of summer and the end of winter.

"The Saturn system undergoes dramatic transitions from winter to summer, and thanks to Cassini, we had a ringside seat," Dr. Linda Spilker, the scientific leader of the mission, was quoted as saying.

NASA: Cassini's First Fantastic Dive Past Saturn
 
Many of the things, which scientists know now, could have never been registered by Cassini if NASA had not decided to extend the mission. For example, five years ago, Cassini first "saw" how Saturn's atmosphere was covered with a giant hurricane at the beginning of autumn and how a haze of hydrocarbons appeared in the planet's atmosphere.

The main achievement of the Cassini mission was the discovery that geysers located on Saturn's sixth moon — Enceladus — can ejecthot water that is generally suitable for the birth and maintenance of life. This discovery urged NASA to consider sending another mission to Saturn and Enceladus in the future.

The Cassini space mission was launched in October 1997 and arrived at Saturn in July 2004. The mission has seen two extensions and is set to end on September 15, 2017. Its observations have generated hundreds of scientific articles.

NASA has discovered 7 Earth-like planets orbiting a star just 40 light-years away

This tiny star has 7 planets that potentially could be suitable for life.

The first step in finding life outside our own planet is to find a planet like our own: small, rocky, and at just the right distance from the star that liquid water could exist on its surface.

That’s why an announcement today from NASA is so exciting: The space agency, along with partners around the world, has found seven potentially Earth-like planets orbiting a star 40 light-years away.

“It’s the first time that so many planets of this kind are found around a same star,” Michaël Gillon, the lead author of the Nature paper announcing the discovery, said in a press conference. “The seven planets … could have some liquid water and maybe life on the surface.”

Three of the planets are directly in the star’s habitable zone, meaning water can mostly likely exist on the surface of them. One of them, Gillon said, has a mass “strongly to suggest a water-rich composition.” And it’s possible that the other four could have liquid water, too, depending on the composition of their atmospheres, the astronomers said.

 The planets “e,” “f,” and “g” — marked in green are directly in the “habitable zone” of this star system. NASA

The exoplanets orbit a star in the constellation Aquarius called Trappist-1. And it’s a solar system very different from our own.

For one, Trappist-1 is a tiny, “ultra-cool” dwarf star. It’s cool because it’s small: just about a tenth of the mass of our sun and about one-thousandth as bright. But its low mass allows its planets to orbit it very closely and remain in the habitable zone.

The distance at which the planets orbit Trappist-1 is comparable to the distance of Jupiter to its moons. All the planets are believed to be rocky, and are all believed to be around the size of Earth, give or take 10 to 20 percent.

The star’s dimness is actually what led to the discoveries of these planets. When astronomers search for exoplanets, they typically look for a temporary dimming of a star — an indication that a planet has passed in front of it. This method makes it hard to find small, rocky worlds orbiting big, bright stars. If the planets are too small, they’ll get washed out.

“Maybe the most exciting thing here is that these seven planets are very well suited for detailed atmospheric study,” Gillon said. The James Webb Space Telescope, set to launch in 2018, will have the ability to measure the chemical composition of exoplanet atmospheres. If the atmospheres contain telltale gases like ozone, oxygen, or methane, life could exist there. “We can expect that in a few years, we will know a lot more about these [seven] planets,” Amaury Triaud, another of the paper’s co-authors, said.

If this all sounds a bit familiar, it’s because astronomers announced three potentially habitable planets around Trappist-1 in May. Today’s reveal adds four more to the mix.

Right now, the astronomers are beginning to study the planets’ atmospheres with the telescopes they have. And from these observations, they feel fairly confident that the worlds are rocky. “For detailed characterization, we will need James Webb,” Triaud said.

In the meantime, we just have our imaginations to fill in the gap. This is an artist’s rendition of what the fifth planet in this bizarre solar system might look like. These planets are believed to be tidally locked to the star, each has a permanent day side and a permanent nice side. And because the planets are so close together, they’d appear in the sky like moons.

 This artist's concept allows us to imagine what it would be like to stand on the surface of the exoplanet Trappist-1f. Dream vacation? NASA/JPL-Caltech

The more Earth-like exoplanets astronomers find in the galaxy, the more they update their estimates of how many Earth-like planets could be out there. “For every transiting planet found, there should be a multitude of similar planets (20–100 times more) that, seen from Earth, never pass in front of their host star,” Nature reporter Ignas Snellen explains in a feature article. And the more exoplanets there are, the more likely it is that life exists on at least one of them.

“With this discovery we’ve made a giant, accelerated leap forward in our search for habitable worlds and life on other worlds potentially,” Sara Seager, a leading exoplanet expert at MIT, said during the announcement. This one star system, she said, gives astronomers many chances to look for life, and refine their understanding of exoplanets in small-star systems.

Also promising: Tiny, cool stars like Trappist-1 are some of the most common in the galaxy. Investigating them will likely yield more exoplanet discoveries. Which will help get us closer to finding places like Earth.

As NASA associate administrator Thomas Zurbuchen said, “Finding another Earth-like planet isn't a matter of if but when.“

Full Moon, Comet Starring in Night Sky Show This Weekend

A full moon and comet share double billing in a special night sky show this weekend.

A lunar eclipse starts everything off Friday night. The moon will pass into Earth's outer shadow, or penumbra. The moon won't be blacked out like in a full eclipse. Only part of the moon will be shaded, but it should be easily visible from much of the world.

Comet 45P, meanwhile, will zoom past Earth early Saturday morning. It will be an extremely close encounter as these things go, passing within 7.7 million miles (12.4 million kilometers) of Earth. Its relative speed: 14.2 miles per second, or a breakneck 51,120 mph.

The comet, glowing green, will be visible in the constellation Hercules. Binoculars and telescopes will help in the search.

Stargazers have been tracking Comet 45P for the past couple of months. The ice ball — an estimated mile across — comes around every five years. It's officially known as Comet 45P/Honda-Mrkos-Pajdusakova, named after the Japanese, Czech and Slovak astronomers who discovered it in 1948. The letter P stands for periodic, meaning it's a recurring visitor to the inner solar system.

The Slooh network of observatories will provide a live broadcast from the Canary Islands for both big events.

The eclipse will last more than four hours, beginning at 5:32 p.m. EST. The action will unfold early Saturday in Europe, Africa and western Asia.

National emergency as Chile fights record forest fires

Drought, heat and commercial foresting have made it easier for fires to spread, killing 11 people and consuming entire towns.

Chile is fighting its worst wildfires on record. Government officials blame both climate change and human action for the blazes.

A decade-long drought has left the South American country tinder-dry and, together with higher than average temperatures, made it easy for the fires to spread. Forty-three people have been arrested and accused of arson.

Forest fires are a regular feature of the hot, dry Chilean summers, which last from December to February, but this years fires have devastated almost a quarter of a million square miles, leading to President Michelle Bachelet declaring a national emergency. “We have never seen anything on this scale in the history of Chile,” she said.

Flammable forests

In addition to local weather patterns, shaped by climate change, a review of Chiles wildfires published in the Global and Planetary Change journal warned that the “pattern, frequency and intensity” of wildfires in the country “has grown at an alarming rate in recent years, partly because of intensive forest management practices that have led to a large amount of flammable fuel in the countrys forests.

In the last few decades, closely planted eucalyptus and pine plantations have covered much of what was previously farmland or native forest. The native forests, with their undergrowth and biodiversity, enjoy much higher humidity, but the commercial forests tend to be dry.

Fire chiefs also blame a lack of fire prevention planning, including failure to provide fire breaks.

“This is a horror, a nightmare without end. Everything has burned”

The worst hit areas are the centre and south of Chile, which is a long, thin country, squeezed between the Andes mountains and the Pacific ocean. The capital, Santiago, is now wreathed in smoke, and images from NASA’s Earth Observatory also show big clouds of smoke covering most of the centre of the country.

So far, 11 people, including several firefighters, have died, thousands have been evacuated and entire towns have been consumed by the flames. Some of the vineyards in the Central Valley, home to many of Chile’s best known wines, have been badly damaged.

More than 11,000 firefighters, including police, military, and civilian personnel and volunteers, are fighting the flames. Other Latin American countries have sent teams and equipment. Temperatures of higher than 100°C have been reported, and power cables have melted.

Russia and the US have sent supertankers, large planes equipped with tanks carrying thousands of litres of water.

Fires continue to threaten

On 29 January fewer than half of 130 active fires were under control. This is a horror, a nightmare without end, said Carlos Valenzuela, mayor of Constitución, a city in the path of advancing fires. “Everything has burned.” The authorities are preparing to evacuate the population of 46,000, unless the winds change direction.

The states most affected are in the central southern part of the country, particularly the regions of OHiggins, Maule and Valparaíso, where Chile’s major port is located. More than 100 vineyards in Maule have already been destroyed by the fires.

Winemaker Sergio Amigo Quevedo has lost six hectares of 120-year-old vines.It is hard to believe that those vines, which you have taken care of with such love and sacrifice, are lost… because of a voracious fire caused by careless men. It is a tremendous pain to lose these ancient vines that we bought in 2008 to preserve them from turning into a forest.

Vineyards in the Colchagua Valley, one of Chile’s most famous wine-producing areas, are also threatened by the encroaching flames, as is the region of Bío-Bío, south of Maule. More than 40 national parks and conservation areas have been temporarily closed to visitors.

This article was produced by Climate News Network

  • Published in World

November’s supermoon will be bigger than it has been since 1948

November’s full moon is special. Not only is it a supermoon — which appears larger than a “regular” full moon — it will be the closest such moon to Earth since January 1948. We won’t see the full moon this close again until Nov. 25, 2034, according to NASA.

In the middle of November, we savor the splendor of a full moon. With any luck, this awe-inspiring moon will lure people outside to breathe the crisp air of the autumnal night sky, spark people to hold hands and spur interest in relishing the heavens.

The moon officially becomes full on Monday at 8:52 a.m. — it won’t be visible on the East Coast at the exact moment of fullness, but it will on the West Coast.

Since the moon’s orbit around Earth is an elliptical shape, there are times when our lunar companion is closest to Earth. This is called perigee. This month, the perigee occurs Nov. 14 at about 6 a.m. — within two hours of the moon becoming officially full — making this fun event an extra-super, perigee full moon.

Astrologer Richard Nolle defined a supermoon in 1979, but the term has really taken off in the past few years. Sometimes it seems as if every moon is a supermoon. Nolle said that a supermoon is a new or full moon that occurs when the moon is within 90 percent of its closest approach to Earth in a given orbit.

The distance between Earth and the moon can range from 221,208 miles at its closest possible point to 252,898 miles at its farthest. That’s a difference of nearly 32,000 miles. This month, it gets close at 221,524 miles between Earth and the moon — just 316 miles from its nearest possible location.

The supermoon isn’t just a fun sight for photographers and skywatchers — it has an actual impact on the coastline. Every year from November through February, the highest tides — called “king tides” — sweep onto the shores during full moons. This is due to the combination of gravity from the moon and sun being the closest to Earth as they will be all year. The tides get even higher during “supermoons” simply because the moon is closer to Earth.

On Sunday afternoon, the nearly-full moon rises at 4:43 p.m. in Washington, while the sun sets at 4:55 p.m. The following morning, the moon sets at 6:36 a.m. — so if you scoot out of bed around 5 a.m., you’ll see the moon low in the western sky plump and full. The full moon rises Monday evening at 5:30 p.m., so look for it close to the eastern horizon.

For any location in the United States or abroad, the Naval Observatory provides rise and set times for the moon and sun.

In October, NASA said that “the perigee full moon can be as much as 14 percent larger and 30 percent brighter than an apogee full moon.” The NASA team goes on to explain, “Hanging high overhead with no reference points to provide a sense of scale, one full moon looks much like any other.”

In other words, for the human eye, it is difficult to perceive the difference between a supermoon and any other.

The next perigee full moon occurs Dec. 14 — the third such moon in an October-November-December lunar trifecta. After that, there will be a perigee full moon on Jan. 1-2, 2018 — when the moon and the Earth will be 221,559 miles apart.

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