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Center for Astrophysics
The mission of the Harvard-Smithsonian Center for Astrophysics (CfA) is to advance our knowledge and understanding of the universe through research and education in astronomy and astrophysics.
American Astronomical Society | Advocates for science since 1899
The American Astronomical Society (AAS), established 1899, is the major organization of professional astronomers in North America. The membership (~7,700) also includes physicists, mathematicians, geologists, engineers and others whose research interests lie within the broad spectrum of subjects now comprising contemporary astronomy. The mission of the American Astronomical Society is to enhance and share humanity's scientic understanding of the Universe
Astronomy in Hawaii
The Big Island of Hawaii is an international astronomy and scientific center. Mauna Kea's summit provides the clearest view of the skies of any location on earth for optical telescopes.
Solar Cycle Linked to Global Climate, Drives Events Similar to El Niño, La Niña - News Release
SkyandTelescope.com - News from Sky & Telescope - A Megascope for Hawaii
Why and how did the Thirty Meter Telescope project decide to build at Mauna Kea?
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TMT will also cost between 1 and 2 billion dollars when all is said and done. This is not quite at the scale of the world’s biggest science projects, like the Large Hadron Collider or the James Webb Space Telescope, but it’s getting there. In fact, TMT and other proposed observatories of this generation may end up being the biggest telescopes on Earth for all time because the funding required to go even larger would more logically be directed towards putting telescopes in orbit.
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Adaptive optics is a big part of TMT’s design. It will work both on Mauna Kea and Armazones, but astronomers expect it will work better on Mauna Kea. This is because the upper atmosphere—the part above the boundary layer—is somewhat less turbulent above Mauna Kea than it is above Armazones. Why? According to Racine it’s partly a function of latitude. Because Mauna Kea is nearer the equator it’s relatively unaffected by the jet streams that flow at higher latitutdes both north and south. Armazones’ upper atmosphere is a bit more turbulent in comparison and so somewhat harder for adaptive optics to deal with.
Technology Review: Blogs: arXiv blog: Fermi Paradox Points To Fewer Than Ten ET Civilisations
Jupiter gets another cosmic punch, shows new bruise - Ars Technica
Over the weekend, Jupiter was apparently struck by an unknown object, probably a comet or an asteroid. The discovery was made by Anthony Wesley in Australia, an amateur astronomer well-known in both the amateur and professional astronomy communities.
Guest Post: Evalyn Gates on Cosmic Magnification (or — Invasion of the Giant Blue Space Amoebas) | Cosmic Variance | Discover Magazine
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This galaxy has been lensed by the warp in spacetime created by the cluster. Light from the galaxy, which lies almost directly behind the center of the cluster but much farther away from us, travels along several curved paths through the cluster lens, producing multiple magnified images of the galaxy. The inset box shows a computer generated model of the unlensed source galaxy, enlarged by a factor of four so that the details, including the spiral arm structure, are visible. Without the lensing power of the cluster, we would see this galaxy as a single small blue smudge.
In general, lensing will both magnify and distort (shear) images of a background source. This lens is fairly unique in that we see large but relatively intact images of the spiral galaxy, which implies that the mass distribution in the central region of the cluster must be nearly uniform.
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This is not just a pretty picture, however – the image packs a lot of scientific information. The authors extract the mass distribution in the cluster (which has implications for cosmological models), measure the mass-to-light ratio of the bright galaxy in the center of the cluster, and use the magnifying power of the lens to search for even more distant galaxies.
The basic idea is to construct a model of the lens, starting with the cluster galaxies and a dark matter halo; then refine the model to reproduce the multiple images that are seen. Using this refined model it’s possible to predict the location of additional images of a given source, and to identify regions of high magnification that can then be examined for multiple images of other sources. Any additional images that are found can be used to further refine the model and so on.
Phoenix Lander Team: It Snows at Night on Mars | Universe Today
Phoenix landed at the north arctic region on Mars (68.22°N, 234.25°E) on May 25th, 2008. On Mars, this was just before the summer solstice. Phoenix operated for 5 months, and was able to observe conditions as the seasons changed from summer to winter, giving science teams an unprecedented look at the planet's changing weather patterns, including frost and precipitation.
ESO - ESO 24/09 - Astronomer's new guide to the galaxy: largest map of cold dust revealed
This new guide for astronomers, known as the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) shows the Milky Way in submillimetre-wavelength light (between infrared light and radio waves [1]). Images of the cosmos at these wavelengths are vital for studying the birthplaces of new stars and the structure of the crowded galactic core.
[0906.0568] The Sustainability Solution to the Fermi Paradox
No present observations suggest a technologically advanced extraterrestrial intelligence (ETI) has spread through the galaxy. However, under commonplace assumptions about galactic civilization formation and expansion, this absence of observation is highly unlikely. This improbability is the heart of the Fermi Paradox. The Fermi Paradox leads some to conclude that humans have the only advanced civilization in this galaxy, either because civilization formation is very rare or because intelligent civilizations inevitably destroy themselves. In this paper, we argue that this conclusion is premature by introducing the "Sustainability Solution" to the Fermi Paradox, which questions the Paradox's assumption of faster (e.g. exponential) civilization growth. Drawing on insights from the sustainability of human civilization on Earth, we propose that faster-growth may not be sustainable on the galactic scale. If this is the case, then there may exist ETI that have not expanded throughout the galaxy or have done so but collapsed. These possibilities have implications for both searches for ETI and for human civilization management.
[0904.0402] A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code
Of the twenty amino acids used in proteins, ten were formed in Miller's atmospheric discharge experiments. The two other major proposed sources of prebiotic amino acid synthesis include formation in hydrothermal vents and delivery to Earth via meteorites. We combine observational and experimental data of amino acid frequencies formed by these diverse mechanisms and show that, regardless of the source, these ten early amino acids can be ranked in order of decreasing abundance in prebiotic contexts. This order can be predicted by thermodynamics. The relative abundances of the early amino acids were most likely reflected in the composition of the first proteins at the time the genetic code originated. The remaining amino acids were incorporated into proteins after pathways for their biochemical synthesis evolved. This is consistent with theories of the evolution of the genetic code by stepwise addition of new amino acids. These are hints that key aspects of early biochemistry may be universal.
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