Follow Friday & Weekly Stumbles For 2010-11-12

This week I recommend to follow @Voyager2 for lots of interesting tweets about news from the Voyager 2 probe. For more Twitter follow suggestions see our astronomy list @TheAstroBlog/astronomy

Weekly Stumbles:

‘Super-Earths’ May Lack a Magnetic Field -Exist as Dead Zones
Rocky planets a few times heavier than Earth that were thought might be life-friendly may lack a protective magnetic field that originates from an iron core that is at least partly molten. A simulation of super-Earths between a few times and 10 times Earth’s mass suggests that high pressures will keep the core solid, according to Guillaume Morard of the Institute of Mineralogy and Physics of Condensed Matter in Paris, France. Without a magnetic field, the planets would be bathed in harmful radiation, and their atmospheres would be eroded away by particles streaming from their stars.

Ancient Mars: “The Water Planet”
Minerals in northern Mars craters observed by two NASA orbiters suggest that a phase in Mars’ early history with conditions favorable to life occurred globally, not just in the south. Southern and northern Mars differ in many ways, so the extent to which they shared ancient environments has been open to question. In recent years, the European Space Agency’s Mars Express orbiter and NASA’s Mars Reconnaissance Orbiter have found clay minerals that are signatures of a wet environment at thousands of sites in the southern highlands of Mars, where rocks on or near the surface are about four billion years old. Until this week, no sites with those minerals had been reported in the northern lowlands, where younger volcanic activity has buried the older surface more deeply.

Solar Explosions Spark Controversy
Nowhere in the Solar System are conditions more extreme than the Sun. Every second it converts millions of tons of matter into energy to create the intense levels of heat and light we expect of our local star. Study the Sun in different wavelengths and its violent nature can really become apparent. The STEREO satellite has been studying the Sun at a wavelength of 304Å and the results support a controversial solar theory.

The Shining: Alien Worlds Observed in Galaxies Beyond Milky Way
With some 500 known exoplanet apparently all around us (galactically speaking), a global team of researchers have kicked it up a notch. Signals shining across millions of light years, from other galaxies, indicate the birth of solar systems – and we can see them. The work is based on spectroscopy, the science of examining what wavelengths of light come in and extracting all kinds of information from it (far more than our eyes, which just say “that’s blue” and call it a day). Every material has a unique emission spectrum (very specific wavelengths they emit) and any intervening material absorbs it (according to the same spectroscopic signature). This technique allows us to ‘see’ even when the light source is too faint or far away to make out detail any other way.

ω Centauri’s Red Giants Confirm Stellar Evolution Models
While science education often focuses on teaching the scientific method (or at least tries to), the real process of science is often far less linear. Theories tie together so many points of data, that making singular predictions that confirm or refute a proposition is often challenging. Such is the case for stellar evolution. The understanding is woven together from so many independent pieces, that the process is more of a roaring sea than a directed river.

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