Milky Way’s Black Hole Devouring Asteroids?

At the center of the Milky Way galaxy (encompasses our solar system) there is a black hole that features a mass of more than three million times that of the sun at its center. This black hole, known as Sagittarius A (SGR A for short), has been detected through various sources of radiation that stem from the direction of the center of the galaxy. However, SGR A has now been found to be grazing and vaporizing asteroids that pass near it according to recent data released from NASA’s Chandra X-ray Observatory. This discovery comes with the finding that there is a cloud of trillions of asteroids and comets hovering around the black hole. Such a finding redefines the current environmental criteria for an asteroid or comet to form in space.

SGR A has likely been consuming tremendous numbers of asteroids as of late as the black hole has been emanating x-ray radiation in larger quantities than usual. Black holes hold true to the notion that ‘what goes in must come out,’ so they often spit out high amounts of radiation as they consume stellar objects. The asteroids and comets from the nearby cloud that pass within approximately 100 million miles of SGR A are likely hopelessly shredded. The space rocks are destroyed due to the high tidal forces associated with the black hole’s mass which creates enormous friction. The asteroids and comets are ripped apart in a similar fashion by which Saturn forms its rings with the exception that these rocks burn up like a meteor. This discovery is just one more clue to the overall mystery of the Milky Way galaxy.

Image credit: universetoday.com

Keck Interferometer Winding Down

The Keck Interferometer, linking twin telescopes located atop Mauna Kea in Hawaii and part of NASA’s search for extrasolar planets, now faces its final months of operation due to NASA budget cuts. It is scheduled to shut down in July, though the two telescopes it linked will continue to observe independently of one another. While the Keck telescopes are among the largest in the world for infrared and near-optical observation, financial and political obstacles prevented them from ever reaching their full potential.

Built in the 1990s, the Keck’s twin telescopes were to have been joined by four smaller “outrigger” telescopes that would have dramatically increased the Interferometer’s ability to observe small areas of sky. The telescopes’ combined power would have made visible planets the size of Uranus orbiting nearby stars.

NASA actually built the outriggers several years ago, but they never reached Mauna Kea. NASA withdrew their funding after setbacks in other programs meant to search for exoplanets. This, added to objections from native Hawaiians who have long opposed the presence of an observatory atop what they consider a sacred mountain, along with a court-ordered halt to expansion of the observatory to assess its environmental impact, sounded the death knell for the project. Last year, NASA ultimately withdrew funding for the Interferometer itself.

Keck in Motion from Andrew Cooper on Vimeo.

Image: The Keck Interferometer, with the telescopes’ doors open to equalize temperature inside and outside of the domes. Credit: NASA/JPL

Human Cloning and Space Colonization

Animation of the structure of a section of DNA...

Animation of the structure of a section of DNA. The bases lie horizontally between the two spiraling strands. (Photo credit: Wikipedia)

Could cloning and genetic engineering improve our chances of successful space colonization in the future? For example, what if we identified an exoplanet that is capable of sustaining life and sent frozen embryos on a 10,000 year journey to the planet where they would hatch(?) upon reaching the destination planet? Or perhaps genetic engineering will be required so that humans can evolve to survive life in space or on exoplanets (i.e. longevity, adaptability, etc.). Is this something that is worthy of further examination? Let’s briefly examine the process of cloning today and then decide. Read More →

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)

ResearchBlogging.org

Intelligent Life in the Universe

Source: antwrp.gsfc.nasa.gov

We cannot completely discount the possibility that alien life will look or act like us, not least of all given the statistical probabilities. The laws of natural selection alone may no longer govern humans; however, whilst cloning and gene manipulation may allow human enhancement and the curing of disease, we are still constrained by the physiological limitations hard-coded into our genes. Other carbon-based life forms might utilize the same chemical structures (DNA or even RNA) as information carriers, especially with these molecules found in abundance throughout the interstellar medium. On the other hand they may be completely different. Extrapolate to the practical applications of, say, superstring physics (if it’s right) and maybe they can put their intelligence into non-biological forms. Arthur C. Clarke said that what they could do would be like magic to us. Read More →

Mass Extinctions and Space Exploration

If there were ever a case to be made for space exploration, the very real possibility of mass extinction is certainly reasonable. Our planet won’t be around forever. Whether this is a result of our sun dying or some other cataclysmic event (natural or man-made), humanity must find a way to survive beyond our own planet. Let’s consider mass extinctions further as a justification for continued space exploration. Read More →

Science and Faith: Are They Mortal Enemies?

There is no denying that there have been times when science and religion have been in conflict. Particularly in Western society, it appears that Science and the Christian faith are often pitted against one another. Read More →