The Search for Extraterrestrials Narrows

A large number of experts participated recently at the Astrobiology Science Conference, which was held near Houston, Texas. At the meeting, scientists and NASA representatives spoke about the challenges still ahead in discovering forms of life on other planet, both in our solar system and beyond. The participants also addressed the controversy that famed physicists Stephen Hawking set in motion recently, when he said that Earth may be better off not searching for signs of extraterrestrial intelligence.

According to prominent scientists, the best possible places to look for alien life are currently in the process of being pinned down, and addressed in future space missions. The conference was held to mark the 50th anniversary of the quest for life in other places in the Universe. On Wednesday, NASA experts said that the American space agency was at the time considering a number of no less than 28 future space missions, all of which will be aimed at discovering alien life.

“We're interested and prepared to discover any form of life,” explained during a teleconference NASA Headquarters senior astrobiology scientist Mary Voytek. “Astrobiology and the search for life is really central to what we should be doing next in the exploration of the solar system,” added Steve Squyres, who is a planetary scientists at the Cornell University, in Ithaca, New York. The expert is also the principal science investigator of the Mars Exploration Rovers project, which manages the twin geology robots Spirit and Opportunity.

He mentioned that potential targets for astrobiology research could include the Red Planet, Mercury, as well as numerous moons of gas giants such as Jupiter and Saturn, such as Titan, Enceladus and Europa. According to Squyres, a sample-return mission to Mars would prove “invaluable” for this field of research, and would contribute to advancing our knowledge of how the planet looked like before it became the cold, desolate wasteland it is today.

“I personally think if we're ever going to be able to show that there was past life on Mars – if there was past life on Mars – I think we're going to need to study the samples here on Earth rather than [with robots]. I think if we had the rocks back tomorrow and I had them in my lab, I think we could solve this problem,” added University of California in Los Angeles (UCLA) research scientist Bill Schopf, quoted by Space.

Cassini Images First Extraterrestrial Lightnings

Image comment: This image from NASA's Cassini spacecraft -- the first of its kind -- shows lightning on Saturn's night side flashing in a cloud that is illuminated by light from Saturn's rings
Image credits: NASA / JPL-Caltech / Space Science Institute / University of Iowa

The NASA Cassini spacecraft can add another world first to its already-impressive tally of accomplishment. Scientists at the Pasadena, California-based NASA Jet Propulsion Laboratory (JPL) announce that the orbiter is the first probe ever to image lightning strikes on another planet. The explorations robot has been orbiting the gas giant Saturn since July 1, 2004, and it has already sent back exquisite and outstanding images of the planet, its moons and its intricate ring system.

With the newly-received data, investigators at NASA were able to piece together the first short video clip of lightning discharges on another planet. In addition to the video components, the film is also completed by the crackle of radio waves, which Cassini's sensitive instruments detected when the electrical discharges took place.

“This is the first time we have the visible lightning flash together with the radio data. Now that the radio and visible light data line up, we know for sure we are seeing powerful lightning storms,” says Space Research Institute radio and plasma wave science team associate member, Georg Fischer. The facility is located in the city of Graz, Austria.

“What's interesting is that the storms are as powerful – or even more powerful – at Saturn as on Earth. But they occur much less frequently, with usually only one happening on the planet at any given time, though it can last for months,” adds Cassini imaging science subsystem team member Andrew Ingersoll. The expert is based at the California Institute of Technology (Caltech), which houses and manages the JPL.

“The visible-light images tell us a lot about the lightning. Now we can begin to measure how powerful these storms are, where they form in the cloud layer and how the optical intensity relates to the total energy of the thunderstorms,” concludes Caltech expert Ulyana Dyudina, who was the first person to see the lightnings on Saturn. He is also an associate of the Cassini imaging team. Details of the discovery have already been accepted for publication in an upcoming issue of the esteemed scientific journal Geophysical Research Letters.

The Cassini-Huygens mission was a cooperative project of NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI). The JPL manages the Cassini-Huygens mission for NASA Science Mission Directorate, at the agency's Headquarters in Washington DC. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The Huygens mission landed successfully on Titan in January, 2005, and began relaying data from the surface. Though never designed to serve as a lander, the instrument continued to send signals for about 90 minutes after impact.

Happy 50th Birthday SETI

SETI's Allen Telescope Array via SETI Institute

Fifty years ago today, on April 8th, 1960, a Cornell astronomy professor named Frank Drake pointed a radio telescope at the star Tau Ceti in the hope of hearing broadcasts from extraterrestrial intelligence. Naturally, he didn't hear anything out of the ordinary. But with this experiment, Drake began the decades-long search for aliens, known as the Search for Extraterrestrial Intelligence (SETI), that celebrates its 50th anniversary today. Over the last half century, SETI has failed at its initial goal of contacting aliens, but succeeded mightily in bringing new attention to astronomy, helping to develop cloud computing, and inspiring generations of new scientists.

In the 1960s, SETI drew considerable interest from NASA, the National Science Foundation, and the famous astronomer Carl Sagan, but 1977 marked the high point for SETI. In that year, Drake and Sagan successfully lobbied NASA to equip the the Voyager Probe with a golden disc inscribed with information about Earth on one side, and recordings of pop, classical, and traditional music on the other. Ideally, when Voyager left our solar system, it would be found by aliens who would decode the disc, learning about our planet's life. It remains the only physical SETI message every sent out into deep space.

Also in 1977, the SETI-operated Big Ear radio telescope received the historic "Wow!" signal, a 72-second-long burst of powerful radio waves. At the time, the scientists interpreted the Wow signal as the only burst ever detected that might have actually originated in an extraterrestrial civilization. Subsequent searches failed to find a repeat of the signal, and in the years since scientists have produced a number of more likely explanations for the signal's source. However, the Wow signal is still the closest SETI ever got to receiving a message from ET.

While SETI obviously failed at finding actual alien intelligence, it continues to inspire to this day. SETI At Home, a screen saver that helped scientists parse through huge amounts of data, set the stage for programs used today by Berkley's biology lab and the Large Hadron Collider. And closer to SETI's original mission, the development of telescope technology advanced enough to detect exoplanets has revitalized the search for ET's in recent years by locating Earth-like planets circling distant stars.

So happy 50th, SETI! Here's to another 50 years as productive as the last, and maybe even finding some little green men in your next half century of groundbreaking research.

How To Respond When E.T. Says Hello

In 1977 NASA's Voyager 1 and 2 spacecraft launched into space carrying phonographs called the Golden Records containing pictures and sounds meant to show extraterrestrials a glimpse of life on Earth. Credit: NASA.

If mankind ever does receive a signal from extraterrestrials, one of our first decisions may be what to write back. As director of Interstellar Message Composition at the SETI Institute, psychologist Douglas Vakoch has thought a lot about this question.

"The challenge of constructing any interstellar message is trying to anticipate what you and your recipient have in common," Vakoch said. "One thing we can guarantee is they won't be native speakers of English or Swahili or Chinese."

And the same problem applies to any incoming message to Earth.

"It's very reasonable to think that we will know there's an extraterrestrial out there, that we will have a message that is distinctly artificial, but that we won't be able to decipher it," Vakoch said.

So choosing a language and means to communicate is just as difficult as figuring out what you want to say. A language based on mathematics and scientific principles is a good idea, Vakoch said, because presumably if aliens are advanced enough to send or receive a signal across the abyss of space, then they'll have some scientific understanding.

Humankind already has some experience sending messages crafted for alien eyes. One of the most famous of these is the collection of sounds and images contained on the Voyager Golden Records, two phonograph records that were packed aboard the Voyager 1 and 2 spacecraft before they were launched in 1977 on trajectories that have recently taken them beyond the solar system.

"I think the richest description of ourselves that has been sent into space is the Voyager interstellar records," Vakoch said. "They include greetings in 55 languages, over a hundred pictures describing life on Earth."

The contents of the records were chosen by a committee chaired by the late Cornell University astronomer Carl Sagan. They contained recordings of natural sounds such as thunder and bird calls, as well as music from cultures around the world. But Vakoch said these messages were largely symbolic, because most scientists admit the chances of another species intercepting these spacecraft are very slim since they have barely travelled beyond the outskirts of the solar system so far in the 33 years they've been in space. However, even if our postcards to aliens are never received, the act of crafting them may be a worthwhile exercise.

"Let's step aside from our daily concerns for a moment, and let's think about what we would want to say if our words are going to last a thousand years," Vakoch said.

An interesting aspect of the records, he pointed out, is that they emphasize the positive aspects of life on Earth, while ignoring bleaker realities such as war and environmental degradation.

"It really highlights our natural tendency in making contact in putting our best foot forward," he said. "It's the natural way to meet strangers. You don't typically tell them about all your problems on a first date." Though this is an understandable inclination, he said that advanced extraterrestrials may find it very intriguing to hear about the problems that humans face on a day-to-day basis.

"We have a lot of problems as a species that we're struggling with," Vakoch said. "We're not sure if we're even going to survive as a species on our planet. I think a more informative message would be actually to talk about some of the challenges we face because I think that's one of the defining characteristics of our civilization."

In a recent project called "Earth Speaks," the SETI Institute solicited public suggestions about what to say in a communication to aliens.

"One of the most common messages coming in to Earth Speaks is the simple 'Help,'" Vakoch said.

Or perhaps people shouldn't bother composing a message at all. Another SETI scientist, astronomer Seth Shostak, has proposed that we just broadcast everything on the Google servers out to aliens.

"Instead of trying to think of what's fundamental, just send them a lot of data and let them sort through and find the pattern," Vakoch said.

Vakoch discussed some of the issues around interstellar message composition in a recent paper in the journal Acta Astronautica.

First Extraterrestrial Hurricane Discovered

Image comment: Images showing the hurricane raging on at Neptune's south pole

Image credits: Statia Luszcz-Cook / UCB

Scientists peering over old and recent images of the gas giant Neptune, the eight planet from the Sun, were recently amazed to discover an eerily familiar pattern in the way clouds at the planet's south pole were behaving. Their analysis revealed that the region was at the moment battered by what could best be described as a hurricane, as clouds at the location appeared to be trapped in a massive vortex. The process is very likely to be going on for a few years, as even the images delivered by the Voyager spacecraft showed indications of them, Technology Review reports.

For many years, astronomers have known that something odd is taking place at Neptune's south pole. Images sent back by the Voyager spacecraft had revealed the existence of a bright spot at the location. However, since the probe was only flying by, experts had to wait until the technology to view the gas giant developed sufficiently. About three years ago, in July of 2007, they snapped a series of high-resolution infrared images of the planet's pole, using the massive 10-meter-aperture W.M. Keck II telescope, which is based on the summit of Mauna Kea, in Hawaii. The team adds that the feature was also demonstrated using other ground-based observatories, but at much lower levels of detail.

The 2007 image showed a strange event – the bright spot appeared to have divided in two, and then to form a single block again within only a few days. Since then, experts have been shifting through the data, in an attempt to determine what had happened. Their analysis was summed up yesterday, March 19, by a team of experts from the University of California in Berkeley (UCB), led by scientist Statia Luszcz-Cook. The group proposes that the formations are in fact methane clouds, which appear to be trapped inside a very powerful mixture of winds at Neptune's south pole. Their suggestion is based on the fact that similar structures were discovered on Saturn.

In this case, the NASA/ESA Cassini spacecraft, which has been orbiting the gas giant since 2004, sent back detailed information proving that the events were caused by clouds caught in very powerful vortexes. Luscz-Cook and the UCB team say that the behaviors of clouds on the two planets are remarkably similar, and that they also bear resemblance to atmospheric events here on Earth. “The structure of Saturn's south polar vortex possesses similarities with terrestrial hurricanes, such as a well-formed central eye, concentric eyewalls and a surrounding ring of strong convection,” the group says.