Explore some of the mysteries of the cosmos. These news articles deal with all things science and astronomy. Black holes, gamma ray bursts, supernovas etc.
Some of the comets that make their way to Earth's neighborhood from the frigid outer reaches of the solar system likely follow a different route than previously thought, new modeling suggests.
The study's findings, detailed in the July 31 issue of the journal Science, are good news for our planet (especially in light of Jupiter's recent impact ): Comets from this region should rarely cross Earth's orbit, and so aren't a collision concern.
In turn these rare encounters mean that these comets are unlikely to be the causes of past mass extinction events.
The recent bruising Jupiter received from a cosmic impact is a violent reminder that our solar systemis a shooting gallery that sometimes blasts Earth.
So far 784 near-Earth objects more than a half-mile wide have been found.
"If an object of about the same size that just hit Jupiter also hit Earth — it was probably a typical cometary object of a kilometer or so in size — it would have been fairly catastrophic," explained astronomer Donald Yeomans, manager of NASA's Near-Earth Object program office at the Jet Propulsion Laboratoryin Pasadena, Calif.
Scientists have ruled out the chances of an Earth impact for all of these 784 large NEOs. Still, lesser objects also pose a risk, and researchers estimate more than 100 large NEOS remain to be found.
Watchers in Asia have seen the longest total solar eclipse this century, with large areas of India and China plunged into darkness.
Amateur stargazers and scientists travelled far to see the eclipse, which lasted six minutes and 39 seconds at its maximum point.
The eclipse could first be seen early on Wednesday in eastern India.
It then moved east across India, Nepal, Burma, Bangladesh, Bhutan, China, Japan and the Pacific.
The eclipse first became total over India at 0053GMT, and was last visible from land at Nikumaroro Island in the South Pacific nation of Kiribati. It ended at 0418GMT.
Elsewhere, a partial eclipse was visible across much of Asia.
The space rocks that slammed into the glaciers of eastern Canada some 12,900 years ago likely helped wiped out mega-animals like woolly mammoths, and possibly the continent's first human inhabitants called the Clovis peopleadding to evidence that a trio of factors were involved.
The new evidence comes from recently discovered nano-sized diamonds, which researchers say are the strongest clues to date for an argument that could explain the region's die-off during the late Pleistocene epoch.
Scientists have long debated what caused this catastrophic extinction event , sending more than three-fourths of North America's large Ice Age animals and the Clovis people to their graves
To date, two major explanations — human overhunting and climate change — were insufficient by themselves to account for the mega die-off. But add in the comet impact, and all three factors may have combined to create a deadly "perfect storm," said study researcher Allen West of GeoScience Consulting in Arizona.
A solar eclipse that will take place on Wednesday, July 22, 2009 will be a total eclipse of the Sun with a magnitude of 1.080 that will be visible from a narrow corridor through northern India, eastern Nepal, northern Bangladesh, Bhutan, the northern tip of Myanmar, central China and the Pacific Ocean, including the Ryukyu Islands, Marshall Islands and Kiribati. China will be the only country where this solar eclipse can be seen in its totality. Totality will be visible in many Chinese cities such as Chengdu, Chongqing, Wuhan, Hangzhou and Shanghai, as well as over the Three Gorges Dam. A partial eclipse will be seen from the much broader path of the Moon's penumbra, including most of South East Asia and north-eastern Oceania. The eclipse is part of series 136 in the Saros cycle, like the record setting Solar eclipse of July 11, 1991
This is second in the series of three eclipses in a month. There was a lunar eclipse on July 7 and now a solar eclipse on July 22 and then a lunar eclipse on August 6.
This solar eclipse is the longest total solar eclipse that will occur in the twenty-first century, and will not be surpassed in duration until June 13, 2132. Totality will last for up to 6 minutes and 39 seconds, with the maximum eclipse occurring in the ocean at 02:35:21 UTC about 100 km south of the Bonin Islands, southeast of Japan. The North Iwo Jima island is the landmass with totality time closest to maximum.
National Aeronautics and Space Administration (NASA) affirmed after its two decades of Research that Taregana, a place 25 km from Patna in India, is the best location on earth to watch the Total Clear Solar Eclipse on July 22, 2009.
Earthquake and Tsunami Prediction
There has been an earthquake prediction by a software developer who specializes in Computer Game physics and has posted an article on a blog post. His statement is based on an existing theory by James O. Berkland originally posted on National Geographic. According to this speculation, the long total eclipse will cause a undersea Tectonic uplift in south of Japan resulting a major Tsunami . However, the author claims that this is only a theory and acknowledges that he is not qualified to make a formal prediction. The news is swiftly gaining attention worldwide as an electronic chain letter. Mainstream scientists and media have already rejected this hypothesis stating that there is no credible evidence to prove any relationship between solar eclipses and earthquakes.
After one of the longest sunspot droughts in modern times, solar activity picked up quickly over the weekend.
A new group of sunspots developed, and while not dramatic by historic standards, the spots were the most significant in many months.
"This is the best sunspot I've seen in two years," observer Michael Buxton of Ocean Beach, Calif., said on Spaceweather.com.
Solar activity goes in a roughly 11-year cycle. Sunspots are the visible signs of that activity, and they are the sites from which massive solar storms lift off. The past two years have marked the lowest low in the cycle since 1913, and for a while scientists were wondering if activity would ever pick back up.
The mysterious 1908 Tunguska explosion that leveled 830 square miles of Siberian forest was almost certainly caused by a comet entering the Earth's atmosphere, says new Cornell University research. The conclusion is supported by an unlikely source: the exhaust plume from the NASA space shuttle launched a century later.
The research, accepted for publication (June 24, 2009) by the journal Geophysical Research Letters, published by the American Geophysical Union, connects the two events by what followed each about a day later: brilliant, night-visible clouds, or noctilucent clouds, that are made up of ice particles and only form at very high altitudes and in extremely cold temperatures.
"It's almost like putting together a 100-year-old murder mystery," said Michael Kelley, the James A. Friend Family Distinguished Professor of Engineering at Cornell who led the research team. "The evidence is pretty strong that the Earth was hit by a comet in 1908." Previous speculation had ranged from comets to meteors.
When stars go pop, a murderous torrent of energy is released. Life on Earth may have been partly extinguished by just such a violent outburst, but there's little hard evidence yet to justify such a claim. A new study plans to fill in the forensic details.
"We are trying to get a better estimate of how dangerous a particular event will be," says Brian Thomas of Washburn University in Topeka, Kansas.
Thomas and his colleagues will be studying the wide-range of astrophysical phenomena that could fling high energy radiation across interstellar space to Earth's doorstep [as occured in a colossal blast detected in 2004]. The team also will radiate different types of phytoplankton to understand how life would be affected by a stellar blast, since life around the globe is highly dependent on these microscopic plants.
The danger from stellar explosions has been considered before, but this will be the first comprehensive study. "We are building on previous work by broadening it to a wide range of astrophysical events and by making the biological modeling more precise," Thomas says. The project is part of NASA's Exobiology and Evolutionary Biology Program.
For 15 years, scientists have benefited from data gleaned by U.S. classified satellites of natural fireball events in Earth's atmosphere — but no longer.
A recent U.S. military policy decision now explicitly states that observations by hush-hush government spacecraft of incoming bolides and fireballs are classified secret and are not to be released, SPACE.com has learned.
The satellites' main objectives include detecting nuclear bomb tests, and their characterizations of asteroids and lesser meteoroids as they crash through the atmosphere has been a byproduct data bonanza for scientists.
From chaos we all began, and to chaos we'll all return, but not for a very, very long time - 5 billion years or so, more or less.
In the journal Nature today, two French scientists, using arcane mathematical models, predict that in the distant future, the Earth and planet after planet will collide with each other as an inevitable part of the solar system's long-term evolution.
For many millennia, the scientists say, the orbits of the solar system's eight planets will remain stable, just as they are today, but eventually small eccentricities in their flight paths around the sun could cause Mercury, Mars, Venus and Earth to smash into each other, either one at a time or all at once - the ultimate chaotic disaster.
Some of the most powerful explosions in the universe are invisible. But astronomers are a sneaky bunch. By monitoring X-rays and gamma rays, they're able to see what's going on.
Today astronomers said that a certain type of gamma-ray burst, the most energetic explosions in the universe, can light up areas of galaxies, but only in these more energetic wavelengths of the electromagnetic spectrum, revealing intense star formation and death.
A survey of so-called "dark" gamma-ray bursts, which shine brightly in the gamma and X-ray parts of the spectrum but show barely a spark of visible light, found that these beacons can shed light on the dusty corners of galaxies where stars are born.
An asteroid bombardment of Earth nearly 4 billion years ago may have actually been a boon to early life on the planet, instead of wiping it out or preventing it from originating, a new study suggests.
Impact evidence from lunar samples, meteorites and the pockmarked surfaces of the inner planets paints a picture of a violent environment in the solar system during the Hadean Eon 4.5 to 3.8 billion years ago, particularly through a cataclysmic event known as the Late Heavy Bombardment about 3.9 million years ago.
Hundreds of relic black holes may be roaming the outskirts of the Milky Way galaxy trailing telltale streams of stars detectable from Earth, suggest astronomers in a new study.
The black holes are crash victims, ejected from their original host galaxies when worlds collided, a process that Ryan O'Leary and Abraham Loeb, with the Harvard-Smithsonian Center for Astrophysics, suspect was instrumental in building our own galaxy and probably many others.
"Our work was theoretical, but we have an idea of what these clusters would look like, Loeb told Discovery News.
When the sun sneezes it's Earth that gets sick. It's time for the sun to move into a busier period for sunspots, and while forecasters expect a relatively mild outbreak by historical standards, one major solar storm can cause havoc with satellites and electrical systems here.
Like hurricanes, a weak cycle refers to the number of storms, but it only takes one powerful storm to create chaos, said scientist Doug Biesecker of the National Oceanic and Atmospheric Administration's space weather prediction center.
A report by the National Academy of Sciences found that if a storm as severe as one in 1859 occurred today, it could cause $1 trillion to $2 trillion in damage the first year and take four to 10 years to recover.
The 1859 storm shorted out telegraph wires, causing fires in North America and Europe, sent readings of Earth's magnetic field soaring, and produced northern lights so bright that people read newspapers by their light. Today there's a lot more than telegraph lines at stake. Vulnerable electrical grids circle the globe, satellites now vital for all forms of communications can be severely disrupted along with the global positioning system. Indeed, the panel warned that a strong blast of solar wind can threaten national security, transportation, financial services and other essential functions.
The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper soon to be published.
The crater, discovered in 1978 in northern Yucutan and measuring about 180 kilometers (112 miles) in diameter, records a massive extra-terrestrial impact.
When spherules from the impact were found just below the Cretaceous-Tertiary (K-T) boundary, it was quickly identified as the "smoking gun" responsible for the mass extinction event that took place 65 million years ago.
It was this event which saw the demise of dinosaurs, along with countless other plant and animal species. However, a number of scientists have since disagreed with this interpretation.
Could the Sun play a greater role in recent climate change than has been believed? Climatologists had dismissed the idea and some solar scientists have been reticent about it because of its connections with those who those who deny climate change. But now the speculation has grown louder because of what is happening to our Sun. No living scientist has seen it behave this way. There are no sunspots.
The disappearance of sunspots happens every few years, but this time it’s gone on far longer than anyone expected – and there is no sign of the Sun waking up. “This is the lowest we’ve ever seen. We thought we’d be out of it by now, but we’re not,” says Marc Hairston of the University of Texas. And it’s not just the sunspots that are causing concern. There is also the so-called solar wind – streams of particles the Sun pours out – that is at its weakest since records began. In addition, the Sun’s magnetic axis is tilted to an unusual degree. “This is the quietest Sun we’ve seen in almost a century,” says NASA solar scientist David Hathaway. But this is not just a scientific curiosity. It could affect everyone on Earth and force what for many is the unthinkable: a reappraisal of the science behind recent global warming.
The sun's activity is winding down, triggering fevered debate among scientists about how low it will go, and what it means for Earth's climate. Nasa recorded no sunspots on 266 days in 2008 - a level of inactivity not seen since 1913 - and 2009 looks set to be even quieter. Solar wind pressure is at a 50-year low and our local star is ever so slightly dimmer than it was 10 years ago.
Sunspots are the most visible sign of an active sun - islands of magnetism on the sun's surface where convection is inhibited, making the gas cooler and darker when seen from Earth - and the fact that they're vanishing means we're heading into a period of solar lethargy.
Where will it all end? Solar activity varies over an 11-year cycle, but it experiences longer-term variations, highs and lows that can last around a century.
You may want to thank David French in advance. Because, in the event that a comet or asteroid comes hurtling toward Earth, he may be the guy responsible for saving the entire planet.
French, a doctoral candidate in aerospace engineering at North Carolina State University, has determined a way to effectively divert asteroids and other threatening objects from impacting Earth by attaching a long tether and ballast to the incoming object. By attaching the ballast, French explains, "you change the object's center of mass, effectively changing the object's orbit and allowing it to pass by the Earth, rather than impacting it."
Sound far-fetched? NASA's Near Earth Object Program has identified more than 1,000 "potentially hazardous asteroids" and they are finding more all the time. "While none of these objects is currently projected to hit Earth in the near future, slight changes in the orbits of these bodies, which could be caused by the gravitational pull of other objects, push from the solar wind, or some other effect could cause an intersection," French explains.
The Sun is the dimmest it has been for nearly a century.
There are no sunspots, very few solar flares - and our nearest star is the quietest it has been for a very long time.
The observations are baffling astronomers, who are due to study new pictures of the Sun, taken from space, at the UK National Astronomy Meeting.
The Sun normally undergoes an 11-year cycle of activity. At its peak, it has a tumultuous boiling atmosphere that spits out flares and planet-sized chunks of super-hot gas. This is followed by a calmer period.
Last year, it was expected that it would have been hotting up after a quiet spell. But instead it hit a 50-year year low in solar wind pressure, a 55-year low in radio emissions, and a 100-year low in sunspot activity.
According to Prof Louise Hara of University College London, it is unclear why this is happening or when the Sun is likely to become more active again.
"There's no sign of us coming out of it yet," she told BBC News.
Exactly 20 years from today, an asteroid about the size of a 25-story building will come closer to Earth than the networks of communications satellites orbiting the planet.
The chance of an impact are extremely remote — only about 1 in 45,000 — but the asteroid, named Apophis , will be back. Analysis of the asteroid's orbit show it will return to Earth seven years later.
Astronomers don't yet know if Apophis' second visit will be a rendezvous or a collision , as its orbit will be bent by Earth's gravity during the 2029 flyby.
"It can't even be said for certain what side of the sun (the asteroid) will be on in," said Jon Giorgini, a senior analyst with the Solar System Dynamics group at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
It was one of the most important changes to have happened to the Earth's atmosphere and it was the reason why today we can breathe life-giving oxygen. And yet the Great Oxidation Event has remained a mystery – until now.
Without oxygen, life on Earth would not exist as we know it. It has provided the supercharged air that has fuelled an explosion in the diversity and size of all living organisms, from the smallest shrimp to the biggest dinosaur. About 21 per cent of air is oxygen, a vital ingredient for living organisms to carry out the most efficient method of converting food into energy using aerobic respiration. Yet an oxygen-rich atmosphere did not always exist, and the explanation for how it came about has eluded generations of scientists.
Now a team of researchers led by Kurt Konhauser of the University of Alberta in Edmonton, Canada, has come up with a convincing explanation for why oxygen suddenly began to accumulate in the early atmosphere of the Earth about 2.7 billion years ago, when life consisted of nothing more complex than single-cell microbes. The Great Oxidation Event happened, they believe, when one group of oxygen-destroying microbes began to die off, leaving another group of oxygen-producing microbes to gain the ascendancy. The trigger for this event was a fall in a trace metal called nickel, which led to the inexorable rise of oxygen – and life – on Earth.
On March 29th, 2009, at approximately 9:45 pm EDT, people along the Atlantic coast of the USA between Maryland and North Carolina witnessed bright lights in the sky and heard thunderous booms. It was probably a meteoritic fireball--a small, random asteroid entering Earth's atmosphere and exploding. News reports of a falling Russian rocket are probably wrong. The booster stage of a Russian Soyuz spacecraft did indeed reenter Earth's atmosphere on March 29th, but not over the Atlantic coast. According to data published by US Strategic Command, however, the Russian booster reentered near Taiwan (24° N, 125° E) at 11:57 pm EDT, more than two hours after the Atlantic Coast event.
The largest mass extinction in the history of the earth could have been triggered off by giant salt lakes, whose emissions of halogenated gases changed the atmospheric composition so dramatically that vegetation was irretrievably damaged.
At least that is what an international team of scientists has reported in the most recent edition of the Proceedings of the Russian Academy of Sciences (Dokladi Earth Sciences). At the Permian/Triassic boundary, 250 million years ago, about 90 percent of the animal and plant species ashore became extinct. Previously it was thought that volcanic eruptions , the impacts of asteroids , or methane hydrate were instigating causes.
The mysterious boom and flash of light seen over parts of Virginia Sunday night was not a meteor, but actually exploding space junk from the second stage of a Russian Soyuz rocket falling back to Earth, according to an official with the U.S. Naval Observatory.
"I'm pretty convinced that what these folks saw was the second stage of the Soyuz rocket that launched the crew up to the space station," said Jeff Chester of the Naval Observatory in Washington, D.C.
Residents of the areas around Norfolk and Virginia Beach, Va., began calling 911 last night with reports of hearing a loud boom and seeing a streak of light that lit up the sky, according to news reports.
During the Maunder Minimum, a period of diminished solar activity between 1645 and 1715, sunspots were rare on the face of the sun, sometimes disappearing entirely for months to years. At the same time, Earth experienced a bitter cold period known as the "Little Ice Age."
Were the events connected? Scientists cannot say for sure, but it's quite likely. Slowdowns in solar activity -- evidenced by reductions in sunspot numbers -- are known to coincide with decreases in the amount of energy discharged by the sun. During the Little Ice Age, though, few would have thought to track total solar irradiance (TSI), the amount of solar energy striking Earth's upper atmosphere. In fact, the scientific instrument needed to make such measurements -- a spaceborne radiometer -- was still three centuries into the future.
IT IS midnight on 22 September 2012 and the skies above Manhattan are filled with a flickering curtain of colourful light. Few New Yorkers have seen the aurora this far south but their fascination is short-lived. Within a few seconds, electric bulbs dim and flicker, then become unusually bright for a fleeting moment. Then all the lights in the state go out. Within 90 seconds, the entire eastern half of the US is without power.
A year later and millions of Americans are dead and the nation's infrastructure lies in tatters. The World Bank declares America a developing nation. Europe, Scandinavia, China and Japan are also struggling to recover from the same fateful event - a violent storm, 150 million kilometres away on the surface of the sun.
It sounds ridiculous. Surely the sun couldn't create so profound a disaster on Earth. Yet an extraordinary report funded by NASA and issued by the US National Academy of Sciences (NAS) in January this year claims it could do just that.
Over the last few decades, western civilisations have busily sown the seeds of their own destruction. Our modern way of life, with its reliance on technology, has unwittingly exposed us to an extraordinary danger: plasma balls spewed from the surface of the sun could wipe out our power grids, with catastrophic consequences.
Science + Astronomy 
Explore some of the mysteries of the cosmos. These news articles deal with all things science and astronomy. Black holes, gamma ray bursts, supernovas etc.
