Sagan Day Essays

Carl Sagan. 1934-1996

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Tuesday (11/09) is Carl Sagan Day — a chance to remember the legacy of one of the great spokespersons for science. The folks over at the Kepler spacecraft website held an essay contest, inviting the public to submit writings inspired by the imagery that Sagan created in his allegory of The Shores of the Cosmic Ocean. (Regrettably, I didn’t write about this beforehand to give Universe Today readers a heads-up.) The essays — which also include guest essays by notables such as Jill Tartar and Seth Shostak — are now available to read, and are all well worth the trip over to the Kepler website, especially if Sagan had an impact on your thought processes (as he did on mine). I hope you’ll check it out.

By the way, I am currently attending a joint meeting of the National Association of Science Writers ad the Council for the Advancement of Science Writing at Yale University and thus will not have the opportunity to post many articles the next couple of days. But the rest of the UT team will work to keep you updated on the news. While here, I’ll have the chance to talk with some astronomers and cosmologists, and have already met a lot of great and wonderful writers.

ISS Particle Detector Ready to Unveil Wonders of the Universe

The AMS-02 will be mounted on the outside of the International Space Station's S3 Truss element. Image Credit: NASA

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The Principal Investigator (P.I.) for the Alpha Magnetic Spectrometer-2 (AMS-02) experiment, Professor Samuel Ting, says that the experiment is already accruing data as it awaits its February 2011 launch date. Scheduled to fly aboard the final flight of the space shuttle Endeavour, STS-134, AMS-02 will search through cosmic rays for exotic particles, antimatter and dark matter. The experiment will be mounted to the outside of the International Space Station (ISS) and will require no spacewalks to attach.
Continue reading “ISS Particle Detector Ready to Unveil Wonders of the Universe”

Missing Molecules in Exoplanet Atmospheres

Artist's View of Extrasolar Planet HD 189733b

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Every day, I wake up and flip through the titles and abstracts of recent articles posted to arXiv. With increasing regularity, papers pop up announcing the discovery of a new extra-solar planet. At this point, I keep scrolling. How many more hot Jupiters do you really want to hear about? If it’s a record setter in some way, I’ll read it. Another way I’ll pay attention is if there’s reports of detections of spectroscopic detection of components of the atmosphere. While a fistful of transiting planets have had spectral lines discovered, they’re still pretty rare and new discoveries will help constrain our understanding of how planets form.

The holy grail in this field would be to discover elemental signatures of molecules that don’t form naturally and are characteristic of life (as we know it). In 2008, a paper announced the first detection of CO2 in an exoplanet atmosphere (that of HD 189733b), which, although not exclusively, is one of the tracer molecules for life. While HD 189733b isn’t a candidate for searches for ET, it was still a notable first.

Then again, perhaps not. A new study casts doubt on the discovery as well as the report of various molecules in the atmospheres of another exoplanet.

Thus far there have been two methods by which astronomers have attempted to identify molecular species in the atmosphere of exoplanets. The first is by using starlight, filtered by the planet’s atmosphere to search for spectral lines that are only present during transit. The difficulty with this method is that, spreading the light out to detect the spectra weakens the signal, sometimes down to the very point that it’s lost in systematic noise from the telescope itself. The alternative is to use photometric observations, which look at the change in light in different color ranges, to characterize the molecules. Since the ranges are all lumped together, this can improve the signal, but this is a relatively new technique and statistical methodology for this technique is still shaky. Additionally, since only one filter can be used at a time, the observations must generally be taken on different transits, which allow the characteristics of the star to change due to star spots.

The 2008 study by Swain et al. that announced the presence of CO2 used the first of these methods. Their trouble started the following year when a followup study by Sing et al. failed to reproduce the results. In their paper, Sing’s team stated,”Either the planet’s transmission spectrum is variable, or residual systematic errors still plague the edges of the Swain et al. spectrum.”

The new study, by Gibson, Pont, and Aigrain (working from the Universities of Oxford and Exeter) suggests that the claims of Swain’s team were a result of the latter. They suggest that the signal is swamped with more noise than Swain et al. accounted for. This noise comes from the telescope itself (in this case Hubble since these observations would need to be made out of Earth’s atmosphere which would add its own spectral signature). Specifically, they report that since there’s changes in the state of the detector itself that are often hard to identify and correct for, Swain’s team underestimated the error, leading to a false positive. Gibson’s team was able to reproduce the results using Swain’s method, but when they applied a more complete method which didn’t assume that the detector could be calibrated so easily by using observations of the star outside the transit and on different Hubble orbits, the estimation of the errors increased significantly, swamping the signal Swain claimed to have observed.

Gibson’s team also reviewed the case of detections of molecules in the atmosphere of an extra solar planet around XO-1 (on which Tinetti et al. reported to have found methane, water, and CO2). In both cases, they again find that detections of were overstated and the ability to tease signal from the data was dependent on questionable methods.

This week seems to be a bad week for those hoping to find life on extra-solar planets. With this article casting doubt on our ability to detect molecules in distant atmospheres and the recent caution on the detection of Gliese 581g, one might worry about our ability to explore these new frontiers, but what this really underscores is the need to refine our techniques and keep taking deeper looks. This has been a frank reassessment of the current state of knowledge, but does not in any way claim to limit our future discoveries. Additionally, this is how science works; scientists review each others data and conclusions. So, looking on the bright side, science works, even if it’s not exactly telling us what we’d like to hear.

Watch the Effects of Earthquakes Just Hours After They Occur

Princeton University has developed software that can produce realistic “movies” of earthquakes based on complex computer simulations, and these visualizations will be available on the internet within hours of a disastrous upheaval. For example, this video of a 5.7 scale Earthquake off the coast of Peru occurred yesterday, September 22, 2010. “In our view, this could truly change seismic science,” said Princeton’s Jeroen Tromp, a professor of geosciences and applied and computational mathematics, who led the effort. “The better we understand what happens during earthquakes, the better prepared we can be. In addition, advances in understanding seismic waves can aid basic science efforts, helping us understand the underlying physics at work in the Earth’s interior. These visualizations, we believe, will add greatly to the research effort.”

Continue reading “Watch the Effects of Earthquakes Just Hours After They Occur”

New Discovery at the Large Hadron Collider?

Image of a 7 TeV proton-proton collision in CMS producing more than 100 charged particles. Credit: CERN

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Scientists at the Large Hadron Collider reported today they apparently have discovered a previously unobserved phenomenon in proton-proton collisions. One of the detectors shows that the colliding particles appear to be intimately linked in a way not seen before in proton collisions. The correlations were observed between particles produced in 7 TeV collisions. “The new feature has appeared in our analysis around the middle of July,” physicist Guido Tonelli told fellow CERN scientists at a seminar to present the findings from the collider’s CMS (Compact Muon Solenoid) detector.

The scientists said the effect is subtle and they have performed several detailed crosschecks and studies to ensure that it is real. It bears some similarity to effects seen in the collisions of nuclei at the RHIC facility located at the US Brookhaven National Laboratory, which have been interpreted as being possibly due to the creation of hot dense matter formed in the collisions.

CMS studies the collisions by measuring angular correlations between the particles as they fly away from the point of impact.

The scientists stressed that there are several potential explanations to be considered and the they presented their news to the physics community at CERN today in hopes of “fostering a broader discussion on the subject.”

“Now we need more data to analyze fully what’s going on, and to take our first steps into the vast landscape of new physics we hope the LHC will open up,” said Tonelli.

Proton running at the Large Hadron Collider is scheduled to continue until the end of October, during which time CMS will accumulate much more data to analyze. After that, and for the remainder of 2010, the LHC will collide lead nuclei.

Source: CERN

Herschel Finds Water Around a Carbon Star

Herschel image of the carbon star CW Leonis. The arc visible to the left of the star is a bow showck, where the stellar wind encounters the interstellar medium. ESA/PACS/SPIRE/MESS Consortia

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There’s something strange going on around the red giant star CW Leonis (a.k.a. IRC+10216). Deep within the star’s carbon-rich veil, astronomers have detected water vapor where no water should be.

CW Leonis is similar in mass to the sun, but much older and much larger. It is the nearest red giant to the sun, and in its death throes it has hidden itself in a sooty, expanding cloud of carbon-rich dust. This shroud makes CW Leonis almost invisible to the naked eye, but at some infrared wavelengths it is the brightest object in the sky.

Water was originally discovered around CW Leonis in 2001 when the Submillimeter Wave Astronomy Satellite (SWAS) found the signature of water in the chilly outer reaches of the star’s dusty envelope at a temperature of only 61 K. This water was assumed to be evidence for vaporizing comets and other icy objects around the expanding star. New observations with the SPIRE and PACS spectrometers on the Herschel Space Observatory reveal that there’s something much more surprising going on.

“Thanks to Herschel’s superb sensitivity and spectral resolution, we were able to identify more than 60 lines of water, corresponding to a whole series of energetic levels of the molecule,” explains Leen Decin from the University of Leuven and leader of the study. The newly-detected spectral lines indicate that the water vapor is not all in the cold outer envelope of the star. Some of it is much closer to the star, where temperatures reach 1000 K.

No icy fragments could exist that close to the star, so Decin and colleagues had to come up with a new explanation for the presence of the hot water vapor. Hydrogen is abundant in the envelope of gas and dust surrounding carbon stars like  CW Leonis, but the other building block of water, oxygen, is typically bound up in molecules like carbon monoxide (CO) and silicon monoxide (SiO). Ultraviolet light can split these molecules, releasing their stored oxygen, but red giant stars don’t make much UV light so it has to come from somewhere else.

An illustration of the chemical reactions caused by interstellar UV light interacting with molecules surrounding CW Leonis. ESA. Adapted from L. Decin et al. (2010)

The dusty envelopes around carbon stars are known to be clumpy, and that turns out to be the key to explaining the mysterious water vapor. The patchy structure of the shroud around CW Leonis lets UV light from interstellar space into the depths of the star’s envelope. “Well within the envelope, UV photons trigger a set of reactions that can produce the observed distribution of water, as well as other, very interesting molecules, such as ammonia (NH3),” says Decin. “This is the only mechanism that explains the full range of the water’s temperature.”

In the coming months, astronomers will test this hypothesis by using Herschel to search for evidence of water near other carbon stars.

Ars Electronica Festival – Don’t Miss September 6!

Ars Electronica made its debut on September 18, 1979. This festival of art, technology and society spotlighted the emerging Digital Revolution. In his preface to what was going on then, Mayor Franz Hillinger wrote (with specific reference to music): “Ars Electronica is giving rise to a new tonal coloration in which state-of-the-art technology is dovetailing with the intellectual spirit of the age to open up undreamt-of expressive possibilities. […] I am absolutely convinced that this new melodic parlance will ultimately be widely understood. After all, with the help of electronic music, it can even be made visible, be implemented in color, contour, line and rhythm that can be followed onscreen.” He would be proven correct.

Within a few years, Ars Electronica developed into one of the world’s foremost media art festivals. And its growing success was paralleled by the expansion of its annual lineup of events. The 1979 festival proudly presented 20 artists and scientists; in 2008, no fewer than 484 speakers and artists from 25 countries were in attendance. Don’t miss this year’s Live Stream on September 6 at 14:00 UT!

For more than three decades now, this world-renowned event has provided an annual setting for artistic and scientific encounters with social and cultural phenomena that are the upshot of technological change. Symposia, exhibitions, performances and interventions carry these inquiries beyond the confines of conventional conference spaces and cultural venues and take them out into the public sphere and throughout the cityscape. In this process of pervading public spaces and staging festival activities in interesting and appropriate physical settings, Ars Electronica has consistently displayed extraordinary imaginativeness. From the harbor to the mines, from factories to outlying monasteries, unusual locations have repeatedly served as sites of performances and interventions, and have, in turn, been reinterpreted by them.

But the attractiveness of Ars Electronica isn’t attributable solely to participation by renowned scientists and artists from all over the world. Or to remarkable venues. Above all, it’s the international audience that makes the biggest contribution to the festival spirit: the colorful mix of old friends and new faces who conjure up extraordinary circumstances – a “fruitful state of emergency” – every September in Linz.

Be sure to tune in on Monday, September 6th when the Ars Electronica Festival will be featuring Repair dealing with the issues of light pollution!

Orignal Source: ARS Electronica

Could the World Run on Solar and Wind Power?

More than 3,300 solar panels have been erected on a vacant five acres at NASA's Kennedy Space Center. Credit: NASA/Jim Grossman

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Today, the total oil and natural gas production provides about 60 percent of global energy consumption. This percentage is expected to peak about 10 to 30 years from now, and then be followed by a rapid decline, due to declining oil reserves and, hopefully, sources of renewable energy that technologies that will become more economically viable. But will there be the technology breakthroughs needed to make clean and exhaustible energy cost effective?

Nobel prize winner Walter Kohn, Ph.D., from the University of California Santa Barbara said that the continuous research and development of alternate energy could soon lead to a new era in human history in which two renewable sources — solar and wind — will become Earth’s dominant contributor of energy.

“These trends have created two unprecedented global challenges”, Kohn said, speaking at the American Chemical Society’s national meeting. “One is the threatened global shortage of acceptable energy. The other is the unacceptable, imminent danger of global warming and its consequences.”

The nations of the world need a concerted commitment to a changeover from the current era, dominated by oil plus natural gas, to a future era dominated by solar, wind, and alternative energy sources, Kohn said, and he sees that beginning to happen.

The global photovoltaic energy production increased by a factor of about 90 and wind energy by a factor of about 10 over the last decade. Kohn expects vigorous growth of these two energies to continue during the next decade and beyond, thereby leading to a new era, what he calls the SOL/WIND era, in human history, in which solar and wind energy have become the earth’s dominant alternative energies.

Kohn noted that this challenge require a variety of responses. “The most obvious is continuing scientific and technical progress providing abundant and affordable alternative energies, safe, clean and carbon-free,” he said.

One of the biggest challenges might be leveling off global population, as well as energy consumption levels.

Source: American Chemical Society

Record-Setting Freefall Attempt Will be Webcast

Baumgartner during a test flight. Credit: Red Bull Stratos

Want to know what it is like to bail out in near space and freefall 37 km (23 miles) to Earth? You’re about to find out. While no date has been announced yet for Felix Baumgartner’s attempt at breaking the speed of sound during freefall, when it does occur, everyone will be able to watch. The Red Bull Stratos mission team announced today there will be a live television broadcast and online stream of the activities. In-flight cameras will be mounted on the capsule that brings him to 36,500 meters (120,000 feet) altitude via stratospheric balloon, as well as on Baumgartner’s space suit. If successful, this will be the first time in history a freefalling human body will reach supersonic speeds.


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There will also be microphones inside the capsule and inside Baumgartner’s helmet. Those on the capsule will record sound only as long as there is air to carry the soundwaves. When Baumgartner depressurizes the capsule (just before he jumps), those ambient microphones in the capsule will stop picking up sound, but his helmet mic should keep working.

The final launch date, location and live stream details will be announced in the coming weeks on www.redbullstratos.com, on Twitter (@RedBullStratos), and on Facebook.

The current record-holder, USAF Col. (Ret.) Joe Kittinger jumped from 102,800 feet 50 years ago this month. He did not break the speed of sound, although he probably came close. There have been several attempts to surpass Kittinger’s record, but none have succeeded, and people have given their lives for the quest. There are some movies and images from Kittinger’s jump, and his team used spring-wound motion picture cameras warmed by hot-water bottles to document his freefall. Red Bull Stratos will use high-definition video cameras and ultra-high-definition 4K digital cinematography cameras. The challenge will be keeping them cool in an environment where the air is too thin to wick away their heat.

The footage is being taken by FlightLine Films, who will be making a documentary about the jump, so it’s not clear how much will be live on the webcast, although the press release by Red Bull Stratos says the camers will “provide viewers of the worldwide broadcast with perspectives of the capsule, the skyscape and Baumgartner himself.”

And of course there is the main reason to record everything that happens in the jump: for the benefit of scientific research.

We’ll provide an update on the date of the Baumgartner’s jump when it is announced.

Read our preview article on Baumgartner’s record-breaking attempt.