Living in the Universe

Roswell and the Truth

Fourth Week of June

You’ve probably heard the expression “The truth is out there.” Well, I know where the truth is, and it’s not too far from where I live, here in the desert southwest. There’s a small town called Roswell in New Mexico, where the truth is apparently located. If you drive down the desolate highway en route to Roswell and see the weird landscape, you can wonder what strange things have happened there.

This coming weekend is the sixtieth anniversary of the so-called Roswell incident, which will be marked by the city’s annual UFO festival. City officials say that fifty thousand people are expected for the event that will include lectures, book signings, tours, entertainment, and according to the organizers, maybe even an alien abduction or two. Long-term plans are underway for a UFO themed amusement park, complete with an indoor roller coaster that would take passengers on a simulated alien abduction. This park could open as early as 2010. The city has already got a quarter million dollar legislative appropriation for initial planning but the park will mostly be privately built and managed.

In case you’ve been in a time capsule for those sixty years, the original Roswell incident occurred in July 1947 outside the city. A rancher named W. W. “Mac” Brazel went to check on some sheep after a night of storms, He claimed he found some strange debris. Neighbors told Brazel he might have pieces of a flying saucer. On July 8, 1947, a local military office issued a press release saying that pieces of a crashed disk were recovered. The story featured on the front page of the Roswell Daily Record, claiming a flying saucer was captured. That paper is now reproduced and sold to tourists. Other news agencies picked up on the event, albeit in a cursory fashion.

A revised release was soon sent out that said that material was a weather balloon. But stories about requests for tiny coffins and a nefarious plot began to emerge, and Roswell went from small town to alien capital. What exactly happened more than a century ago in the New Mexico desert remains murky, but it has inspired many thousands of people to drive across a godforsaken landscape to visit the small town of roughly forty-five thousand people.

Listen to John Turner, age seventy-eight, who works the main desk of the International UFO Museum and Research Center on Roswell’s North Main Street. “I do know this,” he says. “There are other things out there in the universe.”

When I went to the UFO museum a while back, which used to be a movie theater, I was greeted by an alien dummy wearing a Santa Claus hat. The light posts on the streets of Roswell feature alien heads wearing Santa Claus hats. These benign creatures look utterly incapable of malevolent acts such as abduction and brain surgery. The museum takes visitors through a timeline beginning with newspaper clips and printed affidavits from many who claim to have intimate knowledge of the crash. For an extra donation you can take an audio tour with a walkman. That’s pretty low-tech. The timeline of what happened after the Roswell Incident shows why there are so many conflicting stories about the event. The museum mixes documentary materials and kitsch. It throws in stuff about crop circles and an exhibit detailing how Roswell’s been portrayed in the popular culture.

It is curious how aliens are almost inevitably depicted in this museum and others, by those who claim they’ve been visited by extraterrestrials, as diminutive with oval heads, green skin, and doe-shaped eyes. The most popular part of the museum is purely fictional. It’s the set of an alien autopsy from the 1994 television movie Roswell. This vivid exhibit in which doctors prepare to examine an emaciated alien corpse is on a permanent loan to the museum. Fans of the X-Files will recall a similar scene from one of that TV show’s episodes.

The gift shop takes up a good chunk of the first floor and offers everything imaginable for the alien connoisseur: plush dolls, shot glasses, and magnets that say, “I believe.” There’s also a wide selection of rather unskeptical books and documents on the Roswell incident and a research library for those who want to study the alien phenomenon even better. Downtown Roswell is a hub of alien-themed shops. There’s a Not of This World Coffeehouse and the Cover-up Café. Even businesses like banks have cardboard cutouts of aliens in the windows.

One shop that’s worth a visit is the Alien Zone about one block away from the museum. For a small fee, visitors can see an exhibit called Area 51 that features a display of roughly three foot tall alien models in very human poses. In one display an alien is reading a newspaper in a sauna. Another features a forlorn looking alien lounging in a jail cell in prison stripes. And then of course there’s the inevitable alien autopsy, complete with alien baby fetus in a glass jar in a background, and another life-sized model of an alien stumbling from a crashed spaceship. There’s plenty to do in Roswell. So if you’re bored next weekend and looking for some fun and a little brush with the wild side, head off to Roswell in New Mexico.

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Can Life Survive in Space?

Third Week of June

Can life travel from planet to planet? When a rocky world is hit by a comet or a meteorite, the impact can send pieces of the planetary surface off into space, and some of these ejected rocks may land elsewhere. Here on Earth, we’ve collected a number of meteorites originating from the Moon and Mars, and there are likely to be rocks from Earth sitting on the surfaces of our planetary neighbors. On Earth we know that tiny organisms like bacteria and lichen can live in the crevasses and holes that permeate rocks. These types of life are already adapted to the uncomfortable environment of living inside a rock, and they seem to be resilient when subjected to the harsh conditions of space, surviving radiation and frigid temperatures for short periods of time.

Could life be carried from its rocky home to another world, and once it landed start life on an alien planet? This theory of traveling life is called panspermia. Some scientists have just suggested that life on Earth could be alien-born or have originated on Mars or even further afield, and then have been brought to Earth by a meteorite. Today’s story is experiments of the European Space Agency, where scientists send microbes inside rocks into outer space to see if they could survive the journey.

The first so-called STONE experiments were conducted in 1999 with a goal of confirming that sedimentary rocks could cross the Earth’s atmosphere without being destroyed. On the first STONE flight three different rock samples were fixed into the heat shield of a Photon rocket re-entry capsule: igneous basalt, sedimentary dolomite, and a simulated Martian regolith. The sedimentary dolomite was not totally destroyed by atmospheric re-entry, which indicated it’s possible for similar rocks from Mars to enter the Earth’s atmosphere intact. The dolomite did not acquire a fusion crust. Instead, the surface was exposed to heat and it burned off. This could be one reason why we’ve not yet found a sedimentary Martian meteorite. It lacks that telltale black fusion crust that meteorite hunters are usually looking for. The entry speed of the satellite was seven and a half kilometers per second.

The basalt sample was included in the test because it would develop a fusion crust at the appropriate speed. Unfortunately, that sample was lost, but the simulated Martian regolith provided the proof that the team was looking for. According to one of the team members, “The artificial Martian meteorite was made of small pieces of basalts cemented by carbonated sulfate, and this small bit of basalt had developed a fusion crust.” After launch the rocket orbited the Earth for sixteen days. It then re-entered the Earth’s atmosphere and landed in the Kazakh desert. The dolomite sample dropped out of its casing and landed in the surrounding soil, but it was recovered and the scientists collected the surrounding soil so they could subtract any added contamination. The rocket’s landing was softened by a parachute, which is not a comfort to a meteorite in real life.

Would organisms traveling within a meteorite survive the hard impact of landing in the Earth’s surface? To test this theory people are looking at the stresses bacterial spores receive when they’re ejected from a planetary body. Bacterial spores survive when they are subjected to as much as a million G’s in a centrifuge. Other people looking at impact shocks have put bacterial spores into bullets and then shot them into sand. The spores survive this impact shock, so it seems good evidence that even if there’s no parachute for a meteorite, the shock will not kill the spores. The team confirmed that some microorganisms survive very high impact pressures. Some microorganisms were put between two plates, and a small explosion was used to shock the plates together. The microbes did survive, but scientists also found that photosynthetic organisms with large vegetative cells can’t survive this type of pressure.

While organisms might survive the launch into space and even the impact of the landing, they still might not survive the journey to another world. In the 2004 STONE experiment, all the organisms that were launched into space were killed. There was no evidence for their DNA, and no organisms could be cultured from the recovered rocks. The scientists say this suggests that all of the organisms had completely burned up from the heat of re-entry.

Team member Cockell from Britain’s Open University says, “You might think this is uninteresting because there’s no survival, but in fact it’s very interesting. Because cyanobacteria are photosynthetic, they have to live near the surface of a rock to get enough light energy for their growth. During entry the rock heated up to below the minimum depth at which life would be able to photosynthesize. In other words, because photosynthetic organisms need to be near the surface of a rock to get light, they end up getting extinguished during entry. What this demonstrates is a very specific dispersal filter against photosynthetic microbes being transferred from one planet to another.” Cockell says that organisms might be able to get around this problem by living deeper inside a rock, but still this experiment shows that atmospheric re-entry is a very strong barrier against most photosynthetic organisms, and even bacterial and fungal spores, from being spread between planets.

The story doesn’t end here. Cockell added new microbes to the metamorphic gneiss to see if anything would grow inside. He discovered that organisms grew very quickly. The glassy fusion crust that formed during atmospheric re-entry acted as a tiny greenhouse improving the temperature inside the rock and trapping moistures. He said, “This demonstrates that something biologically damaging such as atmospheric entry improved the habitat for the organisms that survive and later colonized the rock.” Meteorites, while they can be destructive to life when they hit the Earth and may not act as an effective spaceship for life traveling between the worlds, can also create new opportunities for life in the aftermath of an impact.

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Mars Like You’ve Never Seen It

Second Week of June

Today I’ll talk about a story close to home, coming from the University of Arizona, and a press release just a couple of days ago. The mission called HIRISE has released twelve hundred images and launched a new viewer on its website. Anyone connected to the Internet can now see the planet Mars much better than at any time in history through the eye of HIRISE, the most powerful camera ever to orbit another planet. Of course you could also go out and in the evening sky see Mars approaching Jupiter, a nice view in its own right of naked eye astronomy.

Meanwhile, the Arizona based team that runs the High Resolution Imaging Experiment on the Mars Reconnaissance Orbiter has released these images. It’s about 1.7 terabytes of data, the largest single data set ever delivered to NASA’s space mission data laboratory, but also delivered in a user-friendly way for the public to see these images. Thanks to tools on their website, any Internet user can pull up and explore the same remarkable images that thrill and confound scientists. These images have been vital in understanding the history of liquid water on Mars and have yielded clues about the potential of life on the red planet. The mission principle investigator, Alfred McEwen of the University of Arizona’s Lunar and Planetary Lab says, “These images must contain hundreds of important discoveries about Mars. We just need time to realize what they are.”

Such is the power of the Internet and the public sharing of data by scientists that there’s a real possibility that amateur planet studiers will find something exciting in this data. Scientists simply can’t keep up with the high volume and high quality of CCD imaging data of Mars being produced by missions like this. The HIRISE camera takes images of a three and a half mile wide swath as the orbiter flies about eight thousand miles around a hundred and seventy miles above Mars’ surface. For the next eighteen months HIRISE will collect thousands of color, black and white, and stereo images of the Martian surface resolving features as small as forty inches across, about the size of an armchair, covering about one percent of the planet.

The team began releasing selected images on the Internet when science operations began back in November 2006. Since then they’ve been reprocessing all the images taken up to March using the improved calibration or image correction techniques. These are the images that are being released today. The planetary data systems node where the images will reside is used by scientists, students, textbook writers, and many others who simply want to follow the latest discoveries in planetary science. NASA started the archive two decades ago when planetary scientists needed a new system to keep up with the expanding volume of data from NASA missions in a form accessible at any time in the future. As computers evolve scientists always need to be able to access data, which is of course a national resource paid for by the taxpayer.

There’s also a special viewer, a tool to home in on any location within the huge data set and an individual image, which will often be a gigabyte across measuring twenty thousand pixels by fifty thousand pixels. The special tool which was developed by a startup in Boulder, Colorado, is called the IAS viewer. Users can download it free directly from the HIRISE website. The advantage of the viewer technology is that it transmits only the amount of data needed to render that portion of the image on your computer screen. That is, each time a user zooms in on an image they don’t have to download a completely new set of pixels. Instead, the user is downloading only the higher resolution parts of the image data which are added to the image data already downloaded. So the viewer ultimately renders the selected part of the image in high resolution by adding in more and more pixels. This tool has obvious defense, intelligence, and disaster management applications, and it delivers high quality images even on relatively slow Internet connections.

The HIRISE manager says, “I’ve run this at home with my little cable modem. The tool allows you to zoom in on small pieces of the image quickly without downloading all the information.” These images are already producing science results. Some tantalizing recent results include an image of a crater from an impact blast that triggered a hundred thousand little dust avalanches on the Martian surface, and exciting details on the fine layered sedimentary rocks on the plains next to Juventae Chasma which features intriguing repeating layers. The mission has also found buried sedimentary rocks exposed in ancient terrain in the southern highlands and a black hole, which is a possible cavern on Mars. HIRISE saw no detail in the shadow, which is consistent with a deep hole and overhanging walls. South polar geysers, possibly a result from the explosive release of carbon dioxide gas trapped under pressure beneath the carbon dioxide ice, have also been found. HIRISE also found spiders on Mars, a reference to David Bowie no doubt. The spiders are channels near the south pole that apparently converge and flow uphill.

HIRISE has been called the “people’s camera” because the team provides processed images directly to the world to stimulate learning, discussion, and investigation. The team encourages the scientific community and the public to help target and analyze images and give them advice where they should be looking for the next advances in Martian research.

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Planet-Hunters Hit Paydirt

First Week of June

This week astronomers were having their biannual professional meeting where they gather from all around the country and even around the world. This time it was in Honolulu, Hawaii. Yes, it is tough being an astronomer. Over a thousand people were there at the meeting, and one of the most news worthy items was the announcement of twenty-eight new planets outside our solar system, increasing to two hundred and thirty-six the total number of known exoplanets.

The discovery was announced by a pair of teams, the combined work of the California and Carnegie planet search team and the Anglo-Australian planet search team. These planets are among thirty-seven new sub-stellar objects, each orbiting a star but smaller than a star, discovered by those teams within the past year. Seven of the thirty-seven are confirmed brown dwarfs which are failed stars that nevertheless are much more massive than the largest Jupiter-size planets. Two others are borderline and could either be large gas giants or small brown dwarfs.

The California and Carnegie planet search team is headed by Geoff Marcy, professor of astronomy at UC Berkeley, and his colleagues Paul Butler and Debra Fischer, along with Steve Vogt who built the instrument they work with. Marcy and Butler are famous for the first discoveries of exoplanets back in 1995 along with a European team. The Anglo-Australian search team is headed by Chris Tinney from the University of New South Wales and Hugh Jones from the University of Hertfordshire. They have actually published their results over the past year, but this is the first time they’ve presented their entire year’s findings.

In addition to the thirty-seven sub-stellar objects, one of the team members singled out one particular exoplanet as extraordinarily rich. Circling the star Gliese 436, a red dwarf thirty light years distant from Earth, is an ice giant planet I talked about two weeks ago, calculated to be twenty-two Earth masses, slightly larger than Neptune. It’s been observed in transit of its star, which allows them to pin down the mass and calculate the planet’s radius and density. The planet turns out to be very similar to Jupiter. According to the team this planet must be fifty percent rock and about fifty percent water with small amounts of hydrogen and helium. People are going to follow up and try and get the atmospheric composition of this planet, according to the team.

Also among the twenty-eight exoplanets are four new multiple planet systems, plus three stars that probably contain a white dwarf as well as a planet. One of the team members said that at least a third of all stars known to have planets now have more than one, because smaller planets and outer planets of a star are hard to detect. He predicts the percentage will continue to rise as detection methods improve. He’s quoted as saying, “We’re just now getting to the point where if we were observing our own solar system from afar we would be seeing Jupiter.”

Three of the newly reported planets around large stars are between 1.5 and 1.9 times the mass of the Sun. The team focused on massive stars known as A and F stars which have masses between one and a half and two and a half times the mass of the Sun. Planets around these massive stars are normally very hard to detect because they typically rotate fast and have pulsating atmospheres, traits that can hide or mimic a signal from an orbiting star. However, the team discovered that cooler A stars, the sub-giants that have nearly completed hydrogen burning and stabilized for a short period of time, are quiet enough to make planet sized wobbles detectable. So far they have tracked down six previously discovered exoplanets around A stars, and by combining this set with three recently discovered exoplanets, they’re able to draw preliminary conclusions on the statistics.

Only one of the nine planets is within one astronomical unit of their host star, and none is within 0.8 AU of their host star, which is very different from the distribution around Sun-like stars. Even though short period planets are easier to detect, no such planets have been detected around the A stars. Based on the results of this search, they can calculate the odds of Jupiter-like giant planets. It’s about ten percent within two A.U. for stars between one and a half and two solar masses, versus only four percent for Sun-like stars with masses ranging from a half to one and a half solar masses, and only one percent for cool M stars less than about two-thirds the mass of the Sun.

These results are consistent with the popular core accretion model of planet formation. Large planets are expected to be more often observed around massive stars probably because these stars start out with more material in their disks during the early formation period.

Planet hunting has become an industry, and just to see how fast things are moving I went in the few days since the story was issued to the Extrasolar Planets Encyclopedia on the web at http://exoplanet.eu maintained by the European teams. Rather than two hundred and thirty-six, the census as of this past Friday was two hundred and forty-two planets, contained within a hundred and ninety-six planetary systems, including twenty-five multiple planet systems. Four planets were found by microlensing, four by imaging, there are four pulsar planets, and the vast majority have been detected with the Doppler or radial velocity technique. In the short time between this press release and me going to the web, another six planets had been found by other teams around the world. This field is moving quickly indeed.

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