Buzz About Gliese 581g: Doubts of Its Existence; Aliens Signals Detected

Goldilocks Zone

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Ever since the announcement of the discovery of exoplanet Gliese 581g, there has been a buzz in the news, on websites, Twitter – pretty much everywhere, about the first potentially habitable extrasolar planet. But the past couple of days there has been a different sort of buzz about this distant world. Two stories have surfaced and they both can’t be true. The first one is fairly off the deep end: an astrophysicist from Australia claims that while doing a SETI search two years ago, he picked up a “suspicious signal” from the vicinity of the Gliese 581 system, and a couple of websites have connected some dots between that signal and a potentially habitable Gliese 581g.

The second one is more sobering. At an International Astronomical Union meeting this week, other astronomers have raised doubts whether Gliese 581g actually exists.

Unless you’ve been under a rock the past two weeks, you likely know that this newest and most promising of potential habitable extra solar planets was described by the scientists who discovered it as a rocky world about 3 times the mass of Earth, and it orbits within the red dwarf star’s habitable zone, the place that is just right for water to remain as a liquid on a planetary surface. And it is fairly close to us, too, at about 20 light years away, located in the constellation Libra.

Also announced was the discovery of planet ‘f’, a 7-Earth mass planet with a 433-day orbit around Gliese 581.

Astronomer Steven Vogt announced the discoveries by his team, which used the HIRES instrument on the Keck I telescope in Hawaii. They also used 119 measurements from the HARPS instrument on the La Silla telescope at the European Southern Observatory in Chile.

On Monday, Steinn Siggurdson broke the news on his Dynamics of Cats blog that an astronomer who works on HARPS data at the Geneva Observatory, said at the IAU meeting this week that his team could not confirm the existence of Gliese 581 g.

In an article on the Astrobiology Magazine website today (Tuesday) the astronomer, Francesco Pepe, said that not only can they not confirm the existence of planet ‘g’, but also the ‘f’ planet.

In 2009, the Geneva team announced the discovery of planet ‘e’ in the Gliese 581 solar system. At approximately 1.9 Earth masses, this ‘e’ planet is the lowest mass extrasolar planet found at that time, and has a 3.15-day orbital period around the star.

Pepe said they have studied this planet-rich system frequently, gathering a total of 180 data points in 6.5 years (with about 60 of those data points since 2009) and they can only see evidence of the 4 previously announced planets b, c, d, and e.

There is a signal which could possibly be f, but the signal amplitude of this potential fifth planet is very low and basically at the level of the measurement noise, said Pepe.

The planets in the Gliese 581 system were discovered using spectroscopic radial velocity measurements. Planets ‘tug’ on the star they orbit, causing it to shift in position (stars and planets actually orbit a common center of mass). By measuring the star’s movement in the sky, astronomers can figure out what sort of planets are orbiting it. Multi-planet systems create a complicated signal, and astronomers must tease out the spectral lines to figure out what represents a planet, and what is just “noise” – shifts in the star light not caused by an orbiting planet. Astronomers have developed various ways to reduce such noise in their telescopic observations, but it still creates a level of uncertainty in detecting extrasolar planets.

The Geneva team plugged the HARPS data on Gliese 581 into computer models, and the models show “the probability that such a signal is just produced ‘by chance’ out of the noise is not negligible, of the order of several percents,” Pepe said. “Under these conditions we cannot confirm the presence of the announced planet Gliese 581 g.”

While this doesn’t definitively mean Gliese 581g doesn’t exist, it certainly casts doubt on it. More teams will be looking at the Gliese 581 star to try and determine what is really out there. This story is not over yet.

As for the alien signal, this news has met some pretty harsh criticism — even from Dr. Frank Drake, a leader in SETI community. Astronomer Ragbir Bhathal, a scientist at the University of Western Sydney, said he detected an unusual pulse of light nearly two years ago from the same region at Gliese 581, and with the news of the potential habitable world there, his claims came up again. In an article in Space.com Drake said is suspicious because Bhathal would not share his data with anyone.

You can read an article published in 2009 in the Australian about Bhathal’s claimed discovery.

Watch SETI Webcast This Week

The National Radio Astronomy Observatory (NRAO) is sponsoring a workshop this week on the past and next 50 years of SETI (Search for Extraterrestrial Intelligence) an (SETI), and they are webcasting many of the sessions on Monday, Tuesday and Wednesday of this week, September 13-15. The workshop featuring leading scientific researchers as well as authors, historians, religious leaders, and biologists. Viewers will be able to send questions to the presenters. The webcasts begin at 8:30 a.m., EDT, on September 13, 14, and 15, and can be watched above, or at this link.

You can see the workshop schedule at this link.

Drake will webcast his views on “SETI in 2061 and Beyond”, at 8:30 a.m., EDT, on September 15.

“This workshop focuses on a topic that has a profound influence on the way we view ourselves and our place in the Universe,” said Dr. Glen Langston, NRAO astronomer and workshop organizer. “We are pleased to present this to the public through the webcast.”

Astronomy Without A Telescope – How To Impress An Alien (Or Not)

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It’s about fifty years since Frank Drake sent out our first chat request to the wider universe. I say about as I think the official date is 11 April 1960 – but I notice a lot of fifty year anniversary blogs and interviews are already being published, so what the heck, I’m not waiting either.

While no-one is really concerned that we haven’t had an answer back yet, it is a little despondent to have scanned the skies for someone else’s chat request all this time and found nothing.

In a recent New Scientist interview (actually January 2010 – they were really getting in early), Drake refers to his equation delivering an answer in the order of one in 10 million stars having an advanced civilization – and he uses that statistic to indicate it’s too early to think we have done a statistically adequate scan yet.

Nonetheless, the chances of there being advanced civilizations near enough to enable a future United Federation of Planets already looks doubtful.

Drake’s initial communication efforts in Project Ozma were small scale, but his clever and carefully constructed Arecibo message out to Messier 13 (a globular cluster of approximately 300,000 stars) in 1974 aroused some criticism that telling the aliens where we are might result in an invasion.

This is a little implausible, since Messier 13 is 25,000 light years away. By the time the invasion fleet arrives we will either be long gone or have spent the intervening period developing the technology to blast them out of the sky if they don’t turn back immediately.

Actually, that’s probably an important consideration if we ever decide to invade someone. We will need to take a couple of universities along to keep our technology advancing ahead of theirs. However, if we are travelling near the speed of light, the time differential means that they will get ahead anyway. Hmm…

The Arecibo message composed of 1679 bits, being the product of two prime numbers 73 and 23 (i.e. the number of rows and columns). Impressive, huh?

Anyway, here in the 21st century, I want to suggest that more attention should be given to us just not looking stupid. There’s already all the bad TV out there. We can fairly claim that all that was never meant for alien consumption, but recently we advanced humans have quite deliberately transmitted a Beatles song to Polaris and sent a bunch of text messages to Gliese 581. I mean, huh?

Polaris, being a Cepheid variable – and in any case a short-lived and already dying supergiant – was probably never stable enough to support planets, so we probably got away with that one. However, there’s no getting around us sending text messages to Gliese 581c in 2008 (from Ukraine) and subsequently following that up with another set blasted at 581d in 2009 (from Australia, sorry…).

This was because when we recalculated, it was apparent that the exoplanet 581d was more likely to be in the habitable zone of its star than 581c. Hopefully those 20 light year distant aliens will appreciate that the inconsequential shift in the main focus of those two transmissions is an indication of our extreme cleverness.

See, it’s a bit like reading Shakespeare to a dolphin. With no comprehension of the language, you will just look like someone who is content to sit for hours making funny noises while dangling your feet in a pool. But with a bit of comprehension, the dolphin can be reasonably expected to reply – hey Brainiac, I’m a dolphin, what’s forsooth mean?

There are aliens among us who already think we’re a bit daft. How about we first check in with Frank Drake next time we feel like shouting out the window?

Life on Other Planets

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For centuries, men have pondered the possibility of life on other planets and tried to prove its existence. Even before the first shuttle or probe was launched, stories of life on other planets and life invading our own planet, were published prolifically. Whether it’s a desire to connect with others or a burning curiosity to know whether we are truly alone, the question of life on other planets fascinates people from every walk of life.

An article on extraterrestrial life would not be complete without discussing Mars. Mars has been the biggest focus of the ongoing search for life on other planets for decades. This is not just a wild assumption or fancy; there are several reasons why scientists consider Mars the best place to look for extraterrestrial life. One reason why many people, including scientists, look to Mars as a possible source of life is because they believe there may be water on the planet. Since the telescope was first invented, astronomers have been able to see the channels in the terrain that look like canals or canyons. Finding water on a planet is vitally important to proving that life exists there because it acts as a solvent in chemical reactions for carbon-based life.

Another reason astronomers consider Mars as a likely location for life is because there is a good possibility that Mars is in the habitable zone. The habitable zone is a theoretical band of space a certain distance from the Sun in which conditions are optimal for the existence of carbon-based life. Unsurprisingly, Earth is in the middle of the habitable zone. Although astronomers do not know how far this zone could extend, some think that Mars could be in it.

Most astronomers are looking for life that is carbon-based and similar to life on Earth. For instance, the habitable zone only applies to favorable conditions for supporting carbon-based life, and it is definitely possible for forms of life that do not need water to exist.

Astronomers do not limit themselves to our Solar System either, suggesting that we should look at different solar systems. Scientists are planning to use interferometry–an investigative technique that implements lasers, which is used in astronomy as well as other fields– to find planets in the habitable zones of other solar systems. Astronomers believe that there are hundreds of solar systems and thousands of planets, which means that statistically the odds are favorable for finding another planet that supports life. While NASA develops better probes, the search for life continues.

There are a number of sites with more information including life on other planets from Groninger Kapteyn Institute astronomy students and NASA predicts non-green plants on other planets from NASA.

Universe Today has a number of articles concerning life on other planets including searching for life on non-Earth like planets and single species ecosystem gives hope for life on other planets.

Take a look at this podcast from Astronomy Cast on the search for water on Mars.

The Odds of Intelligent Life in the Universe

When it comes to contemplating the state of our universe, the question likely most prevalent on people’s minds is, “Is anyone else like us out there?” The famous Drake Equation, even when worked out with fairly moderate numbers, seemingly suggests the probable amount of intelligent, communicating civilizations could be quite numerous. But a new paper published by a scientist from the University of East Anglia suggests the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve combined with the remaining life span of Earth.

Professor Andrew Watson says that structurally complex and intelligent life evolved relatively late on Earth, and in looking at the probability of the difficult and critical evolutionary steps that occurred in relation to the life span of Earth, provides an improved mathematical model for the evolution of intelligent life.

According to Watson, a limit to evolution is the habitability of Earth, and any other Earth-like planets, which will end as the sun brightens. Solar models predict that the brightness of the sun is increasing, while temperature models suggest that because of this the future life span of Earth will be “only” about another billion years, a short time compared to the four billion years since life first appeared on the planet.

“The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet,” said Watson.

Some scientists believe the extreme age of the universe and its vast number of stars suggests that if the Earth is typical, extraterrestrial life should be common. Watson, however, believes the age of the universe is working against the odds.

“At present, Earth is the only example we have of a planet with life,” he said. “If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect that evolution from simple to complex and intelligent life was quite likely to occur. By contrast, we now believe that we evolved late in the habitable period, and this suggests that our evolution is rather unlikely. In fact, the timing of events is consistent with it being very rare indeed.”

Watson, it seems, takes the Fermi Paradox to heart in his considerations. The Fermi Paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.

Watson suggests the number of evolutionary steps needed to create intelligent life, in the case of humans, is four. These include the emergence of single-celled bacteria, complex cells, specialized cells allowing complex life forms, and intelligent life with an established language.

“Complex life is separated from the simplest life forms by several very unlikely steps and therefore will be much less common. Intelligence is one step further, so it is much less common still,” said Prof Watson.

Watson’s model suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low — less than 0.01 per cent over four billion years.

Each step is independent of the other and can only take place after the previous steps in the sequence have occurred. They tend to be evenly spaced through Earth’s history and this is consistent with some of the major transitions identified in the evolution of life on Earth.

Here is more about the Drake Equation.

Here is more information about the Fermi Paradox.

Original News Source: University of East Anglia Press Release

Meteor Shower Throws Over 100 Meteors per Hour

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With over 100 meteors per hour, the Quadrantid Meteor Shower is one of the latest mergers between Google and NASA, a major asset to space research due to their successful combination of ideas and plans. This peak shower began around 0200 UTC on Friday morning, January 4th, with the jet owned by the founders of Mountain View-based Google flying amongst big science players, such as the SETI research team.

To see this spectacular sight and to partake in a scientific mission, Google carried a team of NASA scientists and their high-technology instruments on board the Google owned Gulfstream V jet, which left the Mineta San Jose International Airport on Thursday late afternoon about 4:30 p.m. Plans were made for a ten-hour flight over the Arctic, returning to home base when the meteor shower mission was accomplished with the resulting data.

The GOOG Google.com Stock Message Board is full of the things that Google has been doing to improve the world—a real biggie was to develop a cheaper solar, wind power for Earth—excellent idea from a company whose corporate motto is to “do not be evil.â€? That plan involved the creation of a research group to develop energy sources that was a cheaper renewable alternative which focuses on solar, wind and any other forms of power through the Renewable Energy “Cheaper Than Coalâ€? project. And of course, lowering Google’s power bill was top of the list before anyone else as a huge incentive.

Last September, as most are aware of, NASA and Google had launched a $2.6 million dollar agreement to let the Google co-founders house their aircraft at Moffett Field while NASA was to be allowed to use it for their science work, such as that of the Quadrantid Meteor Shower. Other prospective plans for Google are to hand out $30 million dollars to any company that successfully comes up with a plan to bring people to the moon. Another plan is to fund a space race through Google’s Lunar X Prize competition.

Original Source: NASA News Release

[email protected] Needs You!

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If your New Year’s resolutions include trying something new, expanding your horizons, or doing something to benefit humanity, this is for you: [email protected] needs more volunteers to help crunch data in the search for extraterrestrial intelligence (SETI). And the easy part is that your desktop computer does all the work.

SETI uses radio telescopes to listen for narrow band-width radio signals from space. Since these signals don’t occur naturally, a detection of such a signal would indicate technology from an extraterrestrial source.

The SETI project at the University of California-Berkley gets data from world’s largest radio telescope in Arecibo, Puerto Rico, which has recently been updated with seven new and more sensitive receivers. The improved frequency coverage for the telescope is now generating 500 times more data for the SETI project than before, and more volunteers are needed to handle the increase in data.

According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day, or 100 terabytes (100,000 gigabytes) per year, about the amount of data stored in the U.S. Library of Congress. “That’s why we need all the volunteers,” he said. “Everyone has a chance to be part of the largest public participation science project in history.”

The [email protected] premise is simple but brilliant: Instead of using a monstrously huge and expensive supercomputer to analyze all the data, it uses lots of small computers, all working simultaneously on different parts of the analysis. Participants download a special screensaver for their home computers, and when the computer is idle, the screensaver kicks in to grab data from UC Berkley, analyze the data and send back a report. [email protected] was launched in May of 1999.

The [email protected] software has now been upgraded to deal with all the new data generated by the updated Arecibo telescope. The telescope can now record radio signals from seven regions of the sky simultaneously instead of just one. It also has greater sensitivity and 40 times more frequency coverage.

So, if the phrase “to search out new life and new civilizations” inspires you, her’s your chance to be part of the largest community of dedicated users of any internet computing project. Currently [email protected] has 170,000 individuals donating time on 320,000 computers.

“Earthlings are just getting started looking at the frequencies in the sky; we’re looking only at the cosmically brightest sources, hoping we are scanning the right radio channels,” said project chief scientist Dan Werthimer. “The good news is, we’re entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them.”

Check out [email protected] here.
Original News Source: UC Berkley Press Release