Comet Pan-STARRS dresses up night skies, visible with naked eye

CAPE CANAVERAL, Florida (Reuters) - The first of two comets heading toward the sun this year made its closest approach to Earth on Tuesday and will be visible in the Northern Hemisphere beginning on Thursday.

Skywatchers in the Southern Hemisphere have been able to see Comet Pan-STARRS for weeks at twilight, even without binoculars or a telescope. The comet came about 100 million miles (161 million km) from Earth on Tuesday.

"As Comet Pan-STARRS was setting on the southwestern horizon, its nucleus was visible to the naked eye," photographer Michael White from Manawatu, New Zealand, wrote to accompany a stunning image of the comet posted on the SpaceWeather.com website.

The comet, officially known as Comet C/2011 L4, was discovered in June 2011 by the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS, in Hawaii.

Comet Pan-STARRS is believed to be a first-time visitor to Earth after being gravitationally bumped out from the Oort Cloud, a repository of small icy bodies located beyond Pluto in the solar system's back yard.

Comets, which are comprised of minerals, rocks and ice, are believed to be remnants from the formation of the solar system some 4.5 billion years ago.

As a comet approaches the sun, some of its ice vaporizes, creating an envelope of gas and dust, called a coma, around its body. The heating also generates two tails, each of which can be more than 1 million miles (1.6 million km) long.

One tail is comprised of dust and the other is made of molecules ionized by sunlight.

Comet Pan-STARRS currently is inside the orbit of Mercury and brightening as it heads toward the sun.

"Observers in the Southern Hemisphere say the comet can be seen with the naked eye even through city lights. Currently, it is about as bright as the stars of the Big Dipper. The comet could become even brighter when it moves into Northern Hemisphere skies in the second week of March," SpaceWeather.com reports.

Northern Hemisphere sky-watchers will get their chance to see the comet beginning on Thursday, though the best views may come later in the month.

"To see it, you will need an unobstructed, cloudless view of the western horizon. It is best to pick a dark spot, away from street lights," University of Hawaii's Institute for Astronomy wrote in a press release.

The comet should be visible in the direction of the setting sun just after the sun slips below the horizon. Twilight and moonlight may make viewing the comet difficult. The best opportunity to see it may be on March 13 when the comet appears just beneath a thin crescent moon, astronomers said.

By the end of the month, Comet Pan-STARRS will appear in the eastern skies just before sunrise, but it will be farther from the sun and Earth and fainter.

Comet Pan-STARRS may just be the warm-up act for another celestial visitor due to arrive in November. If it is not destroyed by the sun, Comet ISON has the potential to be as bright as a full moon, possibly even visible in daylight.

Comet ISON, which was discovered last year by two amateur astronomers in Russia, is expected to pass as close as 684,000 miles (1.1 million km) from the surface of the sun - about four times closer than Comet Pan-STARRS will pass during its closest approach to the sun on Sunday.

(Editing by Cynthia Osterman)

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Quick updates: #scio13, #wjchat, Science Studio, @scifri

LONDON, Feb 8 (Reuters) - Formula One must bring rising costs under control to help struggling teams race on in tough economic circumstances, even if talk of impending crisis is wide of the mark, principals agree. The folding of Spanish-based HRT since the end of last season owed as much to the economic troubles of the team's debt-stricken homeland as to its lack of success on the track but it still flashed up warning signs. ...

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Strange 'Methuselah' Star Looks Older Than the Universe

The oldest known star appears to be older than the universe itself, but a new study is helping to clear up this seeming paradox.

Previous research had estimated that the Milky Way galaxy's so-called "Methuselah star" is up to 16 billion years old. That's a problem, since most researchers agree that the Big Bang that created the universe occurred about 13.8 billion years ago.

Now a team of astronomers has derived a new, less nonsensical age for the Methuselah star, incorporating information about its distance, brightness, composition and structure.

"Put all of those ingredients together, and you get an age of 14.5 billion years, with a residual uncertainty that makes the star's age compatible with the age of the universe," study lead author Howard Bond, of Pennsylvania State University and the Space Telescope Science Institute in Baltimore, said in a statement. [Gallery: The Methuselah Star Revealed]

The uncertainty Bond refers to is plus or minus 800 million years, which means the star could actually be 13.7 billion years old — younger than the universe as it's currently understood, though just barely.

A mysterious, fast-moving star

Bond and his team used NASA's Hubble Space Telescope to study the Methuselah star, which is more formally known as HD 140283.

Scientists have known about HD 140283 for more than 100 years, since it cruises across the sky at a relatively rapid clip. The star moves at about 800,000 mph (1.3 million km/h) and covers the width of the full moon in the sky every 1,500 years or so, researchers said.

The star is just passing through the Earth's neck of the galactic woods and will eventually rocket back out to the Milky Way's halo, a population of ancient stars that surrounds the galaxy's familiar spiral disk.

The Methuselah star, which is just now bloating into a red giant, was probably born in a dwarf galaxy that the nascent Milky Way gobbled up more than 12 billion years ago, researchers said. The star's long, looping orbit is likely a residue of that dramatic act of cannibalism.

Distance makes the difference

Hubble's measurements allowed the astronomers to refine the distance to HD 140283 using the principle of parallax, in which a change in an observers' position — in this case, Hubble's varying position in Earth orbit — translates into a shift in the apparent position of an object.

They found that Methuselah lies 190.1 light-years away. With the star's distance known more precisely, the team was able to work out Methuselah's intrinsic brightness, a necessity for determining its age.

The scientists also applied current theory to learn more about the Methuselah star's burn rate, composition and internal structure, which also shed light on its likely age. For example, HD 140283 has a relatively high oxygen-to-iron ratio, which brings the star's age down from some of the earlier predictions, researchers said.

In the end, the astronomers estimated that HD 140283 was born 14.5 billion years ago, plus or minus 800 million years. Further observations should help bring the Methuselah star's age down even further, making it unequivocally younger than the universe, researchers said. 

The new study was published last month in the Astrophysical Journal Letters.

Follow Mike Wall @michaeldwall. Follow us @Spacedotcom, Facebook or Google+. Originally published on SPACE.com.

Copyright 2013 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Asteroid Resources Could Make Science Fiction Dreams -- and Nightmares -- a Reality

With two private companies, Planetary Resources and Deep Space Industries, proposing to set up asteroid mining, the prospect of accessing limitless wealth beyond the Earth has caused a bit of media speculation about what that could mean.

The question arises, could asteroid resources be used to create the greatest dreams -- and perhaps the worst nightmares -- of science fiction?

Wealth in the sky beyond the dreams of avarice

NASA's Near Earth Object Program's website, quoting the 1990s-era book "Mining the Sky," suggests that there is in the asteroid belt alone enough wealth to provide everyone on Earth $100 billion. Asteroids can be used to build structures on space. Comets can be exploited for water and volatiles. Platinum group metals can be mined to develop high-tech products. One estimate of the value of one asteroid, Amun 3554, a less than mile-wide Earth approacher, is about $20 trillion.

Asteroid wealth to fund interstellar travel

Space.com recently speculated that an influx of asteroid wealth could be used to fund a program of interstellar travel, with perhaps the first crewed star ship leaving Earth by 2100. With NASA working on warp drive concepts and with the hunt for extra-solar Earth-like planets proceeding apace, ironing out all of the problems attended with interstellar travel may be just a matter of funding. The article suggests that the first real-life model of the starship Enterprise might cost somewhere in the range of $1 trillion, an immense amount now, but pocket change in a world where asteroid mining is taking place and the solar system is being economically developed and settled. The dream of "Star Trek" could well be financed by the efforts of free-market capitalists.

Asteroid wealth to fund a death star

Rand Simberg, a space blogger and self-described "recovering aerospace engineer" suggests, with perhaps tongue fully inserted in cheek, another science fiction movie that could become reality thanks the asteroid wealth. Noting the successful White House petition to build a Star Wars-style "Death Star," rejected by the administration partly for fiscal reasons, Simberg seeks to prove that the cost of a moon-sized terror weapon, while immense, would not be quite as great as the White House claimed. Then he suggests that a combination of asteroid wealth, space-based manufacturing and construction, advanced technology and perhaps an excess of megalomania on the part of future politicians could make a Death Star possible. Why anyone would want a moon-sized terror weapon capable of destroying entire planets is another question entirely, but given the flow of wealth from asteroid mining, such things are perhaps economically possible.

Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times, and The Weekly Standard.

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Canada's Arctic glaciers headed for unstoppable thaw: study

OSLO (Reuters) - Canadian glaciers that are the world's third biggest store of ice after Antarctica and Greenland seem headed for an irreversible melt that will push up sea levels, scientists said on Thursday.

About 20 percent of the ice in glaciers, on islands such as Ellesmere or Devon off northern Canada, could vanish by the end of the 21st century in a melt that would add 3.5 cm (1.4 inch) to global sea levels, they said.

Governments are trying to understand every likely centimeter of sea level rise caused by global warming to plan how to protect cities from New York to Shanghai or low-lying coasts from Ghana to Bangladesh.

"We believe that the mass loss is irreversible in the foreseeable future" assuming continued climate change, the scientists, based in the Netherlands and the United States, wrote in the journal Geophysical Research Letters.

Lead author Jan Lenaerts of the University of Utrecht told Reuters that the trend seemed unstoppable because a thaw of white glaciers would expose dark-colored tundra that would soak up more of the sun's heat and further accelerate the melt.

A total melt of the glaciers would take several centuries. Climate change is warming the Arctic faster than the global average.

Most past estimates of Canada's glaciers, based on less precise data of their size and melt rates, pointed to a smaller contribution to sea level rise of perhaps 2 cm this century, Lenaerts said.

The U.N. panel of climate scientists has projected that world sea levels will rise by between 18 and 59 cm this century, or more if a thaw of vast ice sheets in Antarctica or Greenland accelerates.

ALASKA TO PATAGONIA

Canada's glaciers are little studied and often lumped into the panel's estimates with ice in Alaska, Patagonia, Russia and Svalbard off north Norway.

"These glaciers are a significant part of the whole equation and of future sea level rise," said David Vaughan, head of the ice2sea program for studying global warming based at the British Antarctic Survey in England.

"We can't afford to ignore them," he told Reuters. Vaughan was not among the authors of Thursday's study.

"Most attention goes out to Greenland and Antarctica which is understandable because they are the two largest ice bodies in the world," said Michiel van den Broeke, a co-author of the study at Utrecht University.

"We want to show that the Canadian ice caps should be included in the calculations," he said in a statement.

The experts used satellite data of the extent of Canadian glaciers over the past decade to work out a model to project their decline.

The projection of a 20 percent loss of volume was based on a scenario in which world temperatures would rise by 3 degrees Celsius (5.4 F) this century and by 8 Celsius (14.4 F) in the Canadian Arctic, well within most U.N. scenarios.

(Editing by Sonya Hepinstall)

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There Should Be Grandeur: Basic Science in the Shadow of the Sequester

LOS ANGELES (Reuters) - Actress Demi Moore is seeking alimony from estranged husband Ashton Kutcher, according to divorce documents filed in a Los Angeles court on Thursday. Kutcher, the star of CBS television comedy "Two and a Half Men," filed for divorce from the "G.I. Jane" actress in December 2012 after more than a year of separation. Requesting financial support from Kutcher, 35, is an unusual move for Moore, 50, who was one of the top female earners in Hollywood during the 1990s. Her court filing did not specify an amount sought. ...

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Blimps to bolster Washington's air shield in test

WASHINGTON (Reuters) - A pair of big, blimp-like craft, moored to the ground and flying as high as 10,000 feet, are to be added to a high-tech shield designed to protect the Washington D.C. area from air attack, at least for a while.

The bulbous, helium-filled "aerostats" - each more than three quarters the length of a football field at 243 feet - are to be stitched into existing defenses as part of an exercise of new technology ordered by the Defense Department.

The coming addition to the umbrella over Washington is known as Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, or JLENS. Raytheon Co is the prime contractor.

"We're trying to determine how the surveillance radar information from the JLENS platforms can be integrated with existing systems in the National Capital Region," said Michael Kucharek, a spokesman for the North American Aerospace Defense Command.

NORAD, a binational command, is responsible for defending air space over the United States and Canada, including the Washington area with its many pieces of important infrastructure.

The most significant air attack in the area took place on September 11, 2001, when Al Qaeda militants hijacked American Airlines Flight 77, a Boeing 757, and crashed it into the Pentagon.

To expand the time available to detect and defend against any future attacks from commercial aircraft, major changes were made under Operation Noble Eagle, combat air patrols begun after the September 11 attacks.

Airspace restrictions were extended. U.S. Army Sentinel radars for low-altitude radar coverage and short-range Stinger/Avenger missile batteries were deployed.

Washington is currently guarded by an air-defense system that includes Federal Aviation Administration radars and Department of Homeland Security helicopters and fixed-wing aircraft on alert at Reagan National Airport to intercept slow, low-flying aircraft.

EXPECTED BY END OF SEPTEMBER

The JLENS craft are expected to arrive in the capital area by September 30, according to Kucharek, who is also a spokesman for the U.S. Northern Command, which coordinates the Pentagon's homeland defense role.

A "capabilities demonstration," as the test is called, is expected to last as long as three years. Its location is being withheld, pending notification of lawmakers and others.

JLENS craft work in a roughly $450 million pair, known as an orbit, each tethered to mobile moorings. One of the aerostats carries a powerful long-range surveillance radar with a 360-degree look-around capability that can reach out to 340 miles. The other carries a radar used for targeting.

Operating as high as 10,000 feet for up to 30 days at a time, JLENS is meant to give the military more time to detect and react to threats, including cruise missiles and manned and unmanned aircraft, compared with ground-based radar.

The system is also designed to defend against tactical ballistic missiles, large caliber rockets and moving vehicles that could be used for attacks, including boats, cars and trucks.

A success in the U.S. capital area could give a boost to the JLENS program, which has been scaled back sharply along with the Pentagon's other 15 or so lighter-than-air vehicle efforts.

Blimp-like craft offer several advantages compared with fixed-wing aircraft, including lower cost, larger payload capacity and extended time aloft. However, their funding is to fall sharply as Pentagon spending shrinks to help pare trillion-dollar-a-year U.S. deficits.

Peter Huessy, a consultant on nuclear deterrence and missile defense, said the system would compliment current U.S. missile-defense capabilities.

(Reporting By Jim Wolf; Editing by David Brunnstrom)

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