Space

The Baryon Oscillation Spectroscopic Survey  - BOSS - is the largest component of the third Sloan Digital Sky Survey (SDSS-III) and pioneered the use of quasars to map density variations in intergalactic gas at high redshifts, tracing the structure of the young universe.

BOSS charts the history of the universe's expansion and new measures of large-scale structure have yielded the most precise measurement of expansion since galaxies first formed.  


Evidence collected over a period of 16 years by NASA's Rossi X-ray Timing Explorer, a satellite in low-earth orbit equipped with instruments that measured variations in X-ray sources, has led to a paper in the Monthly Notices of the Royal Astronomical Society showing huge clouds of gas orbiting supermassive black holes at the centers of galaxies.

Picture a single cloud large enough to span the solar system from the sun to beyond Pluto's orbit. Now imagine many such clouds orbiting in a vast ring at the heart of a distant galaxy, occasionally dimming the X-ray light produced by the galaxy's monster black hole.
The universe is big - really big. Just our Milky Way galaxy alone is about 300 billion stars, with planets whizzing around them and clouds of gas and dust floating in between.

Then there is our orbiting companion, the Andromeda Galaxy and a small group of galaxies in our Local Group, which is about 3 million light years across.

What is in the vast unknown remains a mystery but a recent paper shed light on our immediate neighborhood - bright galaxies within 35-million light years of the Earth. 

A new study of gamma-ray light may lead to evidence of dark matter, a hypothetical blanket term for whatever must make up most of the material universe.

Using publicly available data from NASA's Fermi Gamma-ray Space Telescope, scholars at the Fermi National Accelerator Laboratory (Fermilab), the Harvard-Smithsonian Center for Astrophysics (CfA), the Massachusetts Institute of Technology (MIT) and the University of Chicago have created new maps and they believe their maps show that the galactic center produces more high-energy gamma rays than can be explained by known sources.

They believe this excess emission is consistent with some forms of dark matter.


Right now a doomed gas cloud is edging ever closer to the supermassive black hole at the center of our Milky Way galaxy. These black holes feed on gas and dust all the time, but astronomers rarely get to see mealtime in action.

Northwestern University's Daryl Haggard has been closely watching the little cloud, called G2, and the black hole, called Sgr A*, as part of a study that should eventually help solve one of the outstanding questions surrounding black holes: How exactly do they achieve such supermassive proportions?


In 2005, NASA's Cassini spacecraft sent pictures back to Earth depicting an icy Saturnian moon spewing water vapor and ice from fractures, known as "tiger stripes," in its frozen surface. It was big news that tiny Enceladus—a mere 500 kilometers in diameter—was such an active place. Since then, scientists have hypothesized that a large reservoir of water lies beneath that icy surface, possibly fueling the plumes. Now, using gravity measurements collected by Cassini, scientists have confirmed that Enceladus does in fact harbor a large subsurface ocean near its south pole, beneath those tiger stripes.


The centimeter-sized fragments and smaller particles that make up the regolith — the layer of loose, unconsolidated rock and dust — of small asteroids is formed by temperature cycling that breaks down rock in a process called thermal fatigue, according to a paper in Nature.


The amount of water present in the moon may have been overestimated by scientists studying the mineral apatite, according to a new computer model created to accurately predict how apatite would have crystallized from cooling bodies of lunar magma early in the moon's history. Their simulations revealed that the unusually hydrogen-rich apatite crystals observed in many lunar rock samples may not have formed within a water-rich environment, as was originally expected.  

Writing in Science, the authors say this discovery has overturned the long-held assumption that the hydrogen in apatite is a good indicator of overall lunar water content.  


Exploding stars, random impacts involving comets and meteorites, and even near misses between two bodies can create regions of great heat and high pressure and researchers have developed a method for analyzing the pressure experienced by tiny samples of organic material that may have been ejected from dying stars before making a long journey through the cosmos.

They investigated a type of aromatic hydrocarbon called dimethylnaphthalene, which should enable them to identify violent events in the history of the universe. 


The heart becomes more spherical when exposed to long periods of microgravity in space, according to a study of 12 astronauts. The research has implications if any progress toward a trip to Mars ever gets made. NASA already has a zero-risk culture and cute robots don't have heart attacks whereas a spaceflight of 18 months or more that could affect astronauts' heart strength may be a concern.

In space, no one can hear your heartbeats - as easily. The heart works a lot less and that leads to less muscle mass, even over a relatively short duration.