Astrobiologists Not Expecting to Find ‘Gray Aliens’

The most enduring symbol of extraterrestrial life has to be the gray alien. With a vaguely humanoid body and strangely elongated features, grays are just human enough to be unnerving to most individuals and have, for the most part, replaced the idea of little green men from Mars. Some people feel that this depiction of life is ridiculous and might even disprove various close encounters.

Skeptics see parallels in science fiction stories dating back to the 19th century. A Swedish novel from 1933 describes a race of extraterrestrials that are very similar to the ever-popular grays. Others claim that portrayals of alien life being similar to humanity are a sign of arrogance. Evolution, according to these skeptics, doesn’t necessarily have to take place in the same way that it has on Earth.

Admittedly, the idea of grays seems pretty far-fetched. Legitimate scientists have taken steps to distance themselves from such portrayals of extraterrestrial races. However, that doesn’t mean that the idea itself is bad. While most descriptions of such life forms are taken from the pages of hoaxes, that doesn’t mean that extraterrestrial creatures wouldn’t necessarily resemble anything on Earth.

Image Credit: San Diego State University

Indeed, Occam’s razor would seem to support this concept. No one should necessarily throw the baby out with the bath water. In fact, there is some scientific evidence for this sort of thinking. Humans are the only understood higher species. Saying that extraterrestrial civilizations would physically resemble human ones takes few assumptions.

Regardless of what theory one subscribes to, it’s easy to see that there is a huge rift between legitimate astrobiological research and what detractors deem UFOlogy. Unfortunately, the latter sometimes gives the former a bad name and may involve events that could be explained away as sleep paralysis or outright dishonesty. While so-called ufologists generally focus on finding gray aliens and UFO’s, astrobiologists generally take a different route by studying the origin, evolution, distribution, and future of life in the universe (here on Earth and beyond). In other words, the two fields are worlds apart (pun intended). More to the point, astrobiologists are only interested in researching things that can actually be studied. This often involves the study of lifeforms that are microscopic in size – a far cry from a gray alien. If we ever do have a bonafide gray alien, I’m certain astrobiologists might want to study it as well. Until that happens however, I think most astrobiologists will remain skeptical regarding the existence of gray aliens.

Regardless of what you believe, this leaves an interesting question unanswered by astrobiologists. If intelligent life were discovered, how would sketchy portrayals of aliens on Earth influence the psyche of those who came into contact with them for real? Only exploration and continued research will yield the answer.

What are your thoughts on gray aliens, astrobiology, etc.?

Searching for Extraterrestrial Microbes

Locating thermophiles in other parts of the universe could very well aid in the search for extraterrestrial life. Most people have agreed that if life is found among the stars, it will be microbial (at least in the near-term future). Many individuals have also suggested that intelligent life forms might very well be extinct in other parts of the universe. If scientists could locate thermophile microbes, they could piece together an archaeological picture of once powerful civilizations.

Taiwan is well known for its hot springs. Most tourists that visit the island end up visiting at least one. Many people like to take relaxing baths in them. Hot springs can be great for people with arthritis. New research is proving that they can also be a great place to find astrobiological data.

Photosynthetic thermophiles that live in hot springs may potentially be removing significant amounts of industrially produced carbon dioxide from the atmosphere. They’ve thrived because of fundamental changes to the atmosphere caused by humanity. In fact, there are some scientists who feel that these microbes could play a vital role in regulating the planet’s climate. That role might become increasingly important in the future.

Planets that were once inhabited by industrially developed civilizations that have since passed might be teeming with life similar to these. If a planet was sufficiently changed by another race of beings, it could have ultimately favored the development of these tiny beings. They could indicate that intelligent lifeforms once inhabited a planet, and that planet could be different today than it was in the past.

While discovering a planet full of microbes would be initially interesting, in the future it could be a relatively common occurrence. Therefore, news services of the future might very well pass by such stories after a few weeks – much like they do today with the discovery of new exoplanets. Finding sufficient numbers of photosynthetic thermophiles would be telling about the history of a world, but it would also require a great deal of geological activity. Then again, there’s nothing to say that other civilizations wouldn’t also have the ability to increase the amount of geological activity on other planets. They might even do it on purpose, as a way of terraforming for instance.

For that matter, humans might want to give that a try. Venus is superheated because of thermal runaway as a result of excess carbon dioxide in the atmosphere. If water were transported to that very hot world, colonists could use the resulting geysers to grow bacteria that would absorb the atmospheric gas.

Reference:
Leu, J., Lin, T., Selvamani, M., Chen, H., Liang, J., & Pan, K. (2012). Characterization of a novel thermophilic cyanobacterial strain from Taian hot springs in Taiwan for high CO2 mitigation and C-phycocyanin extraction Process Biochemistry DOI: 10.1016/j.procbio.2012.09.019

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First-Ever Image of Charge Distribution in a Single Molecule

IBM scientists were able to measure for the first time how charge is distributed within a single molecule. This breakthrough will enable fundamental scientific insights into single-molecule switching and bond formation between atoms and molecules. The ability to image the charge distribution within functional molecular structures holds great promise for future applications such as solar photoconversion, energy storage, or molecular scale computing devices (this has inherent potential within multiple astronomy related areas including potentially astrobiology).

As reported recently in the journal Nature Nanotechnology, scientists Fabian Mohn, Leo Gross, Nikolaj Moll and Gerhard Meyer of IBM Research succeeded in imaging the charge distribution within a single molecule by using a special kind of atomic force microscopy called Kelvin probe force microscopy at low temperatures and in ultrahigh vacuum.

“This work demonstrates an important new capability of being able to directly measure how charge arranges itself within an individual molecule,” states Michael Crommie, Professor in the Department of Physics at the University of California, Berkeley. “Understanding this kind of charge distribution is critical for understanding how molecules work in different environments. I expect this technique to have an especially important future impact on the many areas where physics, chemistry, and biology intersect.”

The new technique provides complementary information about the molecule, showing different properties of interest. This is reminiscent of medical imaging techniques such as X-ray, MRI, or ultrasonography, which yield complementary information about a person’s anatomy and health condition.

The discovery could be used to study charge separation and charge transport in so-called charge-transfer complexes. These consist of two or more molecules and hold tremendous promise for applications such as computing, energy storage or photovoltaics.  In particular, the technique could contribute to the design of molecular-sized transistors that enable more energy efficient computing devices ranging from sensors to mobile phones to supercomputers.

“This technique provides another channel of information that will further our understanding of nanoscale physics. It will now be possible to investigate at the single-molecule level how charge is redistributed when individual chemical bonds are formed between atoms and molecules on surfaces,” explains Fabian Mohn of the Physics of Nanoscale Systems group at IBM Research – Zurich. “This is essential as we seek to build atomic and molecular scale devices.”

Gerhard Meyer, a senior IBM scientist who leads the scanning tunneling microscopy (STM) and atomic force microscopy (AFM) research activities at IBM Research – Zurich adds, “The present work marks an important step in our long term effort on controlling and exploring molecular systems at the atomic scale with scanning probe microscopy.”

For his outstanding work in the field, Meyer recently received a European Research Council Advanced Grant. These prestigious grants support “the very best researchers working at the frontiers of knowledge” in Europe.*

Taking a closer look

To measure the charge distribution, IBM scientists used an offspring of AFM called Kelvin probe force microscopy (KPFM).

When a scanning probe tip is placed above a conductive sample, an electric field is generated due to the different electrical potentials of the tip and the sample. With KPFM this potential difference can be measured by applying a voltage such that the electric field is compensated. Therefore, KPFM does not measure the electric charge in the molecule directly, but rather the electric field generated by this charge. The field is stronger above areas of the molecule that are charged, leading to a greater KPFM signal. Furthermore, oppositely charged areas yield a different contrast because the direction of the electric field is reversed. This leads to the light and dark areas in the micrograph (or red and blue areas in colored ones).

Naphthalocyanine, a cross-shaped symmetric organic molecule which was also used in IBM’s single-molecule logic switch**, was found to be an ideal candidate for this study. It features two hydrogen atoms opposing each other in the center of a molecule measuring only two nanometers in size. The hydrogen atoms can be switched controllably between two different configurations by applying a voltage pulse. This so-called tautomerization affects the charge distribution in the molecule, which redistributes itself between opposing legs of the molecules as the hydrogen atoms switch their locations.

Using KPFM, the scientists managed to image the different charge distributions for the two states. To achieve submolecular resolution, a high degree of thermal and mechanical stability and atomic precision of the instrument was required over the course of the experiment, which lasted several days.

Moreover, adding just a single carbon monoxide molecule to the apex of the tip enhanced the resolution greatly. In 2009, the team has already shown that this modification of the tip allowed them to resolve the chemical structures of molecules with AFM. The present experimental findings were corroborated by first-principle density functional theory calculations done by Fabian Mohn together with Nikolaj Moll of the Computational Sciences group at IBM Research – Zurich.

Image Credit: IBM Research

Reference:

Mohn, F., Gross, L., Moll, N., & Meyer, G. (2012). Imaging the charge distribution within a single molecule Nature Nanotechnology DOI: 10.1038/NNANO.2012.20

* cited from the ERC press release, January 24, 2012:http://erc.europa.eu/sites/default/files/press_release/files/press_release_adg2011_results.pdf

** P. Liljeroth, J. Repp, and G. Meyer, “Current-Induced Hydrogen Tautomerization and Conductance Switching of Naphthalocyanine Molecules” , Science 317, p.1203–1206 (2007), DOI: 10.1126/science.1144366

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Let’s Explore Photosynthesis on Exoplanets

Imagine an astronaut stepping out of a spacecraft onto the surface of an extrasolar planet that is capable of sustaining life. Now imagine the astronaut is greeted by the sight of red colored trees and grass. Such a scenario could be more reality than science fiction because of the variances in photosynthesis theorized to exist in other parts of the Milky Way Galaxy.

Photosynthesis occurs in plants when they use sunlight to create foods from carbon dioxide and water. This process of converting energy from sunlight into chemical energy produces oxygen and causes chlorophyll to form. It is chlorophyll that is responsible for imbuing plants with a healthy green color. The reason this happens is because chlorophyll absorbs more blue and red light waves and fewer green light waves from sunlight. Reflecting the green light waves is what causes the plants to appear green to the human eye.

When the Sun in our solar system radiates light, it reaches the Earth in a particular distribution of colors. As this sunlight passes through the Earth’s atmosphere, the various gases that comprise the atmosphere filter out certain colors before they strike the surface of the Earth. Much of the color that is not absorbed in the atmosphere is red, blue or green. Plants tend to absorb a greater amount of red and blue rays and reflect back green.

Some scientists think that plant life growing under the rays of an extraterrestrial sun could reflect colors other than green after the photosynthesis process is completed. The color that is most commonly visible on alien plants correlates with how colors are distributed in the light radiated by the parent star that strikes the surface of the extraterrestrial world.

The spectral type of a main sequence star can have a direct impact on the coloring of plants. For that reason, coloring can vary from star to star if the spectral type for each star also shows some variance. In a scientific paper published in the March, 2007 issue of Astrobiology magazine, a team of scientists examined how light emitted by another sun would appear from the vantage point of a planet orbiting that host star. Nancy Kiang, author of the paper, said the scientific team determined that the atmosphere of any extrasolar Earth-like planet would feature a chemical composition that is compatible with the chemical composition of its host star. How light from that star is seen on the planet’s surface would be affected by how it is filtered through the atmosphere as it reaches the surface.

Kiang, who works with the Goddard Institute for Space Sciences at NASA, and her team conducted an extensive study where they modeled how sunlight would reach the surface of Earth-sized planets that are hospitable to life from stars of varying spectral types. Kiang’s team speculated that each planet could experience different dominant colors that emerge in plants through photosynthesis based on how hot or cool the sun is that is anchoring that solar system.

Plant life existing on other worlds is not guaranteed to mimic the appearance of plants we are accustomed to seeing on Earth. Planets revolving around a blue star could feature plant life that has a dominant color of yellow or orange and this could lend to forests that boast autumn type colors throughout the growing season on those planets. If a habitable world is located in a binary star system or multi-star system, it could cause some exotic variations in how the plant life grows and appears to the human eye after going through photosynthesis. These planets could have plants that are almost black in color.

In the case of habitable planets around red dwarf stars, all plant life would likely exist underwater. The proximity of the habitable zone around the star would make it difficult for plants to fend off ultraviolet radiation because they could not generate enough energy from infrared light through photosynthesis to create sufficient oxygen to block ultraviolet radiation penetrating the atmosphere.

The idea that differences exist in the photosynthesis process from one planet to the next changes how astrobiologists search for evidence of life on other worlds outside our own solar system. It reinforces the idea that plant and animal life alike have evolved and adapted to fit the unique conditions of this Earth as well as reinforcing the notion that life on other habitable planets would evolve to survive and thrive in a similar manner on other planets. What do you think? Is photosynthesis the same on all planets or do you think it will be vastly different?

References: 
Kiang, N., Siefert, J., Govindjee, ., & Blankenship, R. (2007). Spectral Signatures of Photosynthesis. I. Review of Earth Organisms Astrobiology, 7 (1), 222-251 DOI: 10.1089/ast.2006.0105

Kiang, N., Segura, A., Tinetti, G., Govindjee, ., Blankenship, R., Cohen, M., Siefert, J., Crisp, D., & Meadows, V. (2007). Spectral Signatures of Photosynthesis. II. Coevolution with Other Stars And The Atmosphere on Extrasolar Worlds Astrobiology, 7 (1), 252-274 DOI: 10.1089/ast.2006.0108

Artist’s Impression of an Exoplanet with Moons, Orbiting the Star HD70642 (Photo Credit: David A. Hardy, Astroart.org © PPARC)

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