'Orphan' Alien Planet Found Nearby Without Parent Star

'Orphan' Alien Planet Found Nearby Without Parent Star - Astronomers have discovered a potential "rogue" alien planet wandering alone just 100 light-years from Earth, suggesting that such starless worlds may be extremely common across the galaxy.

The free-floating object, called CFBDSIR2149, is likely a gas giant planet four to seven times more massive than Jupiter, scientists say in a new study unveiled today (Nov. 14). The planet cruises unbound through space relatively close to Earth (in astronomical terms), perhaps after being booted from its own solar system.

 

This artist’s impression shows the free-floating planet CFBDSIR2149, at 100 light-years away the closest such "rogue" world to our own solar system. It does not orbit a star and hence does not shine

"If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space," study leader Philippe Delorme, of the Institute of Planetology and Astrophysics of Grenoble in France, said in a statement.

Orphan planet, or something else?

Delorme and his team discovered CFBDSIR2149 using the Canada-France-Hawaii Telescope, then examined its properties with the European Southern Observatory's Very Large Telescope in Chile.

The newfound object appears to be among a stream of young stars called the AB Doradus moving group, the closest such stream to our own solar system.

Scientists think the AB Doradus stars all formed together between 50 million and 120 million years ago. If CFBDSIR2149 is indeed associated with the group — and researchers cite a nearly 90 percent probability — then the object is similarly young.

And if the discovery team is right about CFBDSIR2149's age, the body is likely a planet, with an average temperature of 806 degrees Fahrenheit (430 degrees Celsius), researchers said.

There's still a slight chance that CFBDSIR2149 is a brown dwarf — a strange object that's larger than a planet but too small to trigger the internal nuclear fusion reactions required to become a full-fledged star. Additional observations should help decide the matter.

"We need new observations to confirm that this object belongs to the AB Doradus moving group," Delorme told SPACE.com via email. "With a good distance measurement and a more accurate proper motion, we will be able to increase (or decrease) the probability that it is indeed a planet."

The new study was published today in the journal Astronomy & Astrophysics.

Billions of starless planets?

The discovery of a starless alien planet would not be shocking, at least not anymore. In the last year or so, astronomers have spotted a number of such orphan worlds — so many, in fact, that some scientists think parentless planets are the rule rather than the exception.

One 2011 study, for example, estimated that rogue worlds outnumber "normal" planets with obvious host stars by at least 50 percent throughout the Milky Way. If that's the case, the galaxy that includes Earth probably also hosts billions of orphan planets.

And gas giants may be in the minority among these solitary wanderers, researchers say.

"We now know that such massive planets are rare and that Neptunes or Earth-mass planets are much more common," Delorme said. "We also know that massive objects are more difficult to eject [from solar systems] than light ones. If you follow the rationale, you deduce that ejected exo-Neptunes and ejected exo-Earths should be much more common than objects like CFBDSIR2149."

It's exciting to have a starless planet so close to Earth, researchers say. Future telescopes should be able to learn a great deal about CFBDSIR2149, since they won't have to contend with the overwhelming glare of a nearby host star.

"This object is a really easy-to-study prototype of the 'normal' giant planets we hope to discover and study with the upcoming generation of direct-imaging instruments," Delorme said. "It will help to improve our forecast of these objects' luminosity and hence help us discover them ?and, once discovered, it will help us understand the physics of their atmospheres." ( space.com )

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'Super-Earth' Alien Planet May Be Habitable for Life

'Super-Earth' Alien Planet May Be Habitable for Life - Astronomers have detected an alien planet that may be capable of supporting life as we know it — and it's just a stone's throw from Earth in the cosmic scheme of things.

The newfound exoplanet, a so-called "super-Earth" called HD 40307g, is located inside its host star's habitable zone, a just-right range of distances where liquid water may exist on a world's surface. And the planet lies a mere 42 light-years away from Earth, meaning that future telescopes might be able to image it directly, researchers said.

"The longer orbit of the new planet means that its climate and atmosphere may be just right to support life," study co-author Hugh Jones, of the University of Hertfordshire in England, said in a statement. "Just as Goldilocks liked her porridge to be neither too hot nor too cold but just right, this planet or indeed any moons that it has lie in an orbit comparable to Earth, increasing the probability of it being habitable."

HD 40307g is one of three newly discovered worlds around the parent star, which was already known to host three planets. The finds thus boost the star's total planetary population to six.

Finding new signals in the data

The star HD 40307 is slightly smaller and less luminous than our own sun. Astronomers had previously detected three super-Earths — planets a bit more massive than our own — around the star, all of them in orbits too close-in to support liquid water.

In the new study, the research team re-analyzed observations of the HD 40307 system made by an instrument called the High Accuracy Radial velocity Planet Searcher, or HARPS.

HARPS is part of the European Southern Observatory's 11.8-foot (3.6 meters) telescope at the La Silla Observatory in Chile. The instrument allows astronomers to pick up the tiny gravitational wobbles an orbiting planet induces in its parent star.

The researchers' new analysis techniques enabled them to spot three more super-Earths around the star, including HD 40307g, which is thought to be at least seven times as massive as our home planet.

HD 40307g may or may not be a rocky planet like Earth, said study lead author Mikko Tuomi, also of the University of Hertfordshire.

"If I had to guess, I would say 50-50," Tuomi told SPACE.com via email. "But the truth at the moment is that we simply do not know whether the planet is a large Earth or a small, warm Neptune without a solid surface."

A jam-packed extrasolar system

HD 40307g is the outermost of the system's six planets, orbiting at an average distance of 56 million miles (90 million kilometers) from the star. (For comparison, Earth zips around the sun from about 93 million miles, or 150 million km, away.)

The other two newfound exoplanets are probably too hot to support life as we know it, researchers said. But HD 40307g — which officially remains a "planet candidate" pending confirmation by follow-up studies — sits comfortably in the middle of the star's habitable zone.

Further, HD 40307g's orbit is distant enough that the planet likely isn't tidally locked to the star like the moon is to Earth, researchers said. Rather, HD 40307g probably rotates freely just like our planet does, showing each side of itself to the star in due course.

The lack of tidal locking "increases its chances of actually having Earth-like conditions," Tuomi said.

The new study has been accepted for publication in the journal Astronomy & Astrophysics.

A candidate for direct observation

Super-Earths have been spotted in other stars' habitable zones before. For example, a team using NASA's prolific Kepler Space Telescope announced the discovery of the potentially habitable world Kepler-22b in December 2011.

Kepler-22b lies 600 light-years away, which is not terribly far considering that our Milky Way galaxy is about 100,000 light-years wide. But HD 40307g is just 42 light-years from us — close enough that future instruments may be able to image it directly, scientists say.

"Discoveries like this are really exciting, and such systems will be natural targets for the next generation of large telescopes, both on the ground and in space," David Pinfield of the University of Hertfordshire, who was not involved in the new study, said in a statement. ( space.com )

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'Next-Door' Alien Planet Still Too Distant to Visit — for Now

'Next-Door' Alien Planet Still Too Distant to Visit — for Now — Astronomers have discovered an alien planet right in our solar system's backyard, but residents of Earth shouldn't get their hopes up for an exploration mission anytime soon. The newfound world is much too far away for probes to visit using current technology, experts say.

Researchers announced Tuesday (Oct. 16) that the scorching-hot alien planet Alpha Centauri Bb, which is about as massive as Earth, resides in the three-star Alpha Centauri system. While no other star is closer to our sun than the Alpha Centauri trio, they're still about 4.3 light-years away, making a close-up look at the planet pretty much impossible right now.

 

Associated Press/ESO, L. Calcada - This artist’s impression made available by the European Southern Observatory on Tuesday, Oct. 16, 2012 shows a planet, right, orbiting the star Alpha Centauri B, center, a member of the triple star system that is the closest to Earth. Alpha Centauri A is at left. The Earth's Sun is visible at upper right. Searching across the galaxy for interesting alien worlds, scientists made a surprising discovery: a planet remarkably similar to Earth in a solar system right next door. Other Earth-like planets have been found before, but this one is far closer than previous discoveries. Unfortunately, the planet is way too hot for life, and it’s still 25 trillion miles away. (AP Photo/ESO, L. Calcada)

A robotic exoplanet mission launching today "would require about 40,000 years to get to Alpha Centauri," Greg Laughlin, an astronomer at the University of California, Santa Cruz, told reporters Tuesday. "So, given our propensity for instant gratification, that's not really an option that's on the table."

But Laughlin, who was not involved in the discovery, added that attitudes could change if researchers made a few more intriguing discoveries in the Alpha Centauri system.

25 trillion miles away

One light-year is about 5.9 trillion miles (9.5 trillion kilometers). So the three stars in Alpha Centauri are more than 25 trillion miles (40 trillion km) from Earth.

To put this huge distance into perspective: NASA's Voyager 1 probe, the most far-flung object ever launched from Earth, is currently about 11.3 billion miles (18.2 billion km) into its journey, cruising toward the edge of our solar system. Voyager 1 has thus covered less than 0.05 percent of the distance to Alpha Centauri Bb — and the probe has been zooming through space for more than 35 years.

New technologies needed

Alpha Centauri Bb sits just 3.6 million miles (6 million km) from its sunlike star, completing one orbit every 3.2 days. As a result, the planet's surface is far too hot to support life as we know it, researchers said.

But the solar systems containing a small, rocky world often have multiple planets, Laughlin said, so it's possible Alpha Centauri Bb has some siblings — perhaps even a world or two out in its host star's "habitable zone," the range of distances that can support liquid water.

If subsequent investigations do indeed find a potentially habitable planet circling Alpha Centauri B — or one of the other two stars in the system, Alpha Centauri A and Proxima Centauri — they may provide the push to get a probe out there, Laughlin said.

"You might see a groundswell of excitement to look at new kinds of propulsion technologies, new kinds of missions that could get to Alpha Centauri — not manned, but putting an unmanned probe there in a relatively short period of time, human-lifespan kinds of time frames," he said.

Of course, some researchers are already trying to develop next-generation, super-fast propulsion systems, which include such concepts as nuclear rockets and antimatter fusion drives.

Whenever such advanced technology becomes workable, it might send people as well as robotic probes hurtling toward Alpha Centauri; the system is one possible target of the 100 Year Starship initiative, a project that aims to lay the foundation for interstellar human spaceflight.

So anyone who longs for humanity to colonize other solar systems should probably be rooting for astronomers to find a planet somewhere in the habitable zones of the Alpha Centauri system.

"I think it really comes down to what the inventory of these stars looks like, whether there will be the extraordinary effort and excitement that are required to do those sorts of really groundbreaking things," Laughlin said. ( SPACE.com )

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Long Before Earth, Asteroids May Have Served as Incubators of Life

Long Before Earth, Asteroids May Have Served as Incubators of Life — Meteorites don't always announce their arrival, but the one bearing down on Canada on Jan. 18, 2000, was not shy. Plunging toward the ground in a roaring fireball, it took aim at Lake Tagish in the British Columbia mountains and — this being winter — smashed itself into fragments on the lake's icy surface.

It wasn't until Jan. 25 and 26 that scientists could travel to the site and collect bits of what was once a meteorite measuring perhaps 13 ft. (4 m) across. Those fragments have been kept frozen to preserve any organic compounds that may have been riding aboard the rock when it crashed and are periodically subjected to scientific analysis. The latest of those studies was published this week in the journal Science, and what the new investigators reported was eye opening: biology may have been incubating on asteroids long before it arose on Earth.

The elements that give rise to life are hardly unique to our planet. Hydrocarbons, the basic molecules from which known life is built, are made of nothing but hydrogen and carbon. Two other key players are oxygen and nitrogen — and all four of them are everywhere in the universe, often combining in interesting ways.

"There's no doubt from astronomical observations that we can see organic compounds out there in space," says geologist and mineralogist Christopher Herd of the University of Alberta, the lead author of the new paper. "You can also cook them up on Earth."

A fragment of the Lake Tagish meteorite

But if raw materials were all it took for life to exist, it would be everywhere. It's not, of course, partly because those extremely simple building blocks have to be processed into slightly less simple ones and on and on through various stages of refinement. Three of the most critical materials produced in this process are amino acids (from which DNA is made); monocarboxylic acids, a suite of hydrocarbons that readily participate in chemical reactions; and macromolecular clumps of organic material called kerogen.

Bits of some of these prebiotic materials have been observed in meteor samples before, and Herd and his colleagues were thus not terribly surprised to find them in the tiny 0.4-in. (1 cm) samples of the Tagish meteorite that they studied. What was unexpected, however, was that they saw all the materials in various stages of development, from their simplest forms to their most complex ones. It was as if the scientists had discovered not only butterflies but also cocoons and caterpillars.

"There was this linear correlation from one stage to the next to the next," says Herd. "We saw the organic materials through five different stages of sophistication."

The Tagish meteor, Herd and his colleagues concluded, must have been operating as a sort of incubator, flying through space and cooking up increasingly elaborate organic compounds until it deposited them in British Columbia. On modern-day Earth, which is saturated with life, a few more organic materials wouldn't make much of a difference. On the original, barren Earth, they could have played a meaningful role — adding at least some extraterrestrial seasonings to the organic soup already bubbling here.

Just how a dead rock flying through icy space could support such elaborate chemical processes is not clear, but Herd has a theory. The Tagish meteor formed the same way all the asteroids and meteors in the solar system formed: accreting out of the primordial swirl of gas and dust that also gave rise to the sun and planets. The oxygen and hydrogen in that cloud would have combined to create at least some water, which would also have been mixed into the matrix of the asteroid. And the gravitational heat generated as the rock was coalescing, coupled with radioactive materials onboard, would have kept the water warm and, in a sense, pulsing.

"It could have operated almost like a hydrothermal cell," says Herd, "with water circulating through the asteroid. After a while, the heat would run out and that process would shut off, and you'd be left with different stages of organic materials."

None of this means that true life could have arisen on asteroids; their warm phase would simply have been too brief. What it does mean is that biological processes may be taking place everywhere in the solar system and that some of the early chemical seeds may have been scattered on Earth. In other words, we have met the aliens — and they are at least partly us. ( time.com )

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Superflare from Crab Nebula Has Astronomers Mystified

Superflare from Crab Nebula Has Astronomers Mystified - The Crab Nebula, the dusty remains of an exploded star, has unleashed a surprisingly massive flare that is five times more powerful than any eruption previously seen from the celestial object, leaving scientists struggling to explain the event, NASA says.

The so-called "superflare" was detected on April 12 by NASA's Fermi Gamma-ray Space Telescope, which is continuously mapping the sky in gamma ray wavelengths in search of gamma-ray bursts, the brightest explosions in the universe.

The Crab Nebula's strong outburst lasted six days, and its exact cause has scientists scratching their heads, especially since the superflare followed an earlier gamma-ray flare from the nebula in January.

"These superflares are the most intense outbursts we've seen to date, and they are all extremely puzzling events," said Alice Harding at NASA's Goddard Space Flight Center in Greenbelt, Md., in a statement. "We think they are caused by sudden rearrangements of the magnetic field not far from the neutron star, but exactly where that's happening remains a mystery."

The outburst observed by Fermi was likely triggered by electrons with energies 100 times greater than can be achieved in any particle accelerator on Earth, scientists said. This makes them the highest-energy electrons known to be associated with any galactic source.

Based on the rise and fall of gamma rays during the April outbursts, scientists estimate that the size of the emitting region must be comparable to our entire solar system.

The Crab Nebula's legacy

The spectacular and colorful Crab Nebula is the wreckage of a dying star that emitted an explosion of light that reached Earth in the year 1054. The former star was located 6,500 light-years away from Earth in the constellation Taurus when it erupted in a brilliant supernova explosion.

At the heart of an expanding gas cloud lies what is left of the original star's core, a super-dense neutron star that spins 30 times a second. With each rotation, the star swings intense beams of radiation toward Earth, creating the pulsed emission characteristic of spinning neutron stars, which are also known as pulsars.

Apart from these pulses, astrophysicists thought the Crab Nebula was a virtually constant source of high-energy radiation. But, in January, scientists representing a variety of space-based observatories, including NASA's Fermi, Swift and Rossi X-ray Timing Explorer, reported long-term changes in brightness at X-ray energies.

"The Crab Nebula hosts high-energy variability that we're only now fully appreciating," said Rolf Buehler, a member of the Fermi Large Area Telescope (LAT) team at the Kavli Institute for Particle Astrophysics and Cosmology, a facility jointly located at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University in California.

Monitoring the Crab Nebula

Since 2009, Fermi and the Italian Space Agency's AGILE satellite have detected several short-lived gamma-ray flares at energies that are hundreds of times higher than the nebula's observed X-ray variations. The observed flares measured energies greater than 100 million electron volts. In perspective, visible light has energies between 2 and 3 electron volts.

The superflare that was detected on April 12 by Fermi's LAT and later by the Italian AGILE satellite, grew about 30 times more energetic than the nebula's normal gamma-ray output, and was about five times more powerful than any previously seen outbursts. On April 16, an even brighter flare erupted, but within a couple of days, the unusual activity completely faded out.

The Crab Nebula's high-energy emissions are still mysterious, but are thought to be the result of physical processes that tap into the neutron star's rapid spin. Theorists generally agree that the flares must arise within about one-third of a light-year from the neutron star, but efforts to locate them more precisely have so far been unsuccessful.

Since September 2010, NASA's Chandra X-ray Observatory has routinely monitored the Crab Nebula in an effort to identify X-ray emissions associated with the outbursts. When Fermi scientists alerted astronomers to the onset of a new flare, Martin Weisskopf and Allyn Tennant at NASA's Marshall Space Flight Center in Huntsville, Ala., activated a set of pre-planned observations using Chandra.

"Thanks to the Fermi alert, we were fortunate that our planned observations actually occurred when the flares were brightest in gamma rays," Weisskopf said. "Despite Chandra's excellent resolution, we detected no obvious changes in the X-ray structures in the nebula and surrounding the pulsar that could be clearly associated with the flare."

Scientists are still searching for the answer, but they think the flares occur as the intense magnetic field near the pulsar undergoes sudden restructuring. Such changes can accelerate particles like electrons to rapid velocities near the speed of light. As these high-speed electrons interact with the magnetic field, they emit powerful gamma rays. ( space.com )

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Mercury, Venus, Mars & Jupiter Converge in Night Sky

Mercury, Venus, Mars & Jupiter Converge in Night Sky - During this month of May, four bright planets will engage in a fascinating dance with each other in the morning sky.

Mercury, Venus, Mars and Jupiter will be involved in a series of conjunctions, joined at the end of the month by a very thin, waning crescent moon. We could even refer to this as a "celestial summit meeting," or more precisely, a series of summit meetings during May 2011.

Twice during May three planets will converge to form a "trio."

According to Belgian calculator Jean Meeus, a trio is when three planets fit within a circle with a minimum diameter of 5 degrees. Such a limit was one that Meeus chose more or less arbitrarily, but as he notes, "We have to make a choice."

On Wednesday (May 11), Mercury, Venus and Jupiter will converge within 2.05-degrees of each other, followed just 10 days later by another trio, this time formed by Mercury, Venus and Mars, which will crowd within a 2.13-degree circle. Then late in the month, on three successive mornings, May 29th, 30th, and 31st, the waning crescent moon will arrive, sweeping past Jupiter, Mars, Venus and Mercury stretched out across the eastern sky from upper right to lower left.

Evil omen? Impending disaster?

What might ancient sky watchers from 500 or 1,000 years ago have ascribed to such a series of gatherings as this?

Most likely, they would have felt a mixture of fear and wonder. A fine example was a case in 1186 A.D. when an unusual gathering of the five planets visible to the naked eye resulted in a near-panic across the whole of Europe after religious leaders predicted that worldwide disasters would result!

Even today, in our modern world, similar fears sometimes arise.

You need only Google-search the date May 5, 2000, and you will find a number of different websites that predicted a variety of disasters attributed to the combined gravitational and tidal forces associated with a gathering of the sun, moon, Mercury, Venus, Mars, Jupiter and Saturn.

One website proclaimed that it would be "one of the most exciting, powerful and transformative celestial events of our millennium according to astronomy and astrology experts."

In many ways, these words sound all too similar to the hype and tripe that has been bandied about during these past few years concerning the Mayan Long Count calendar in 2012.

Needless to say, we all survived the recent 2000 celestial summit and despite what you might hear or read in the coming days ahead, absolutely nothing cataclysmic will take place (at least nothing that can be directly attributed to this impending dawn gathering of the moon and planets).

Tough to see

The only tragedy regarding this display is that those living north of the equator will have a difficult time seeing it.

At first glance there doesn't appear to be any problem concerning the visibility of these objects. Their elongations from the sun will range from 18 degrees to 26 degrees, which should place them all in dark skies. Unfortunately, during May, as seen especially from mid-northern latitudes, the ecliptic is oriented at a shallow angle relative to the eastern horizon at dawn.

As a result, the moon and planets will rise into view during late twilight and will lie very low to the east-northeast horizon by sunrise. To see them, you'll have to make sure not to have any potential obstructions to your visibility such as trees or buildings in that direction.

But coming above the horizon so near to sunrise will also mean that you'll have a fighting chance of catching only Venus (magnitude -4) and Jupiter (magnitude -2) with unaided eyes. Whether you will be able to glimpse zero-magnitude Mercury is debatable, and certainly binoculars will be needed if you have any hope of seeing Mars (magnitude +1).

The crescent moon will also prove to be a visual challenge, being only 2 percent illuminated on May 31. Low-lying clouds or haze near the horizon on any given morning will only reduce your chances of success.

In contrast, those of our SPACE.com readers in the Southern Hemisphere, where the ecliptic at dawn appears at a somewhat steeper angle, will see this ever-changing array somewhat higher and in a somewhat darker sky; more like mid-twilight as opposed to late twilight in the north.

Indeed, those living in far southern locations such as Cape Town, South Africa; Melbourne, Australia; or Dunedin, New Zealand, will have a much better chance of seeing and enjoying this month-long dance of the planets. ( SPACE.com )

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