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Space

Two Earth-Like Exoplanets Don't Actually Exist 102

Two suspected exoplanets, Gliese 581g and 581d, have been shown to not exist, and are instead misinterpretations of data from starspot activity. From the article: "Gliese 581g doesn't exist," said lead author Paul Robertson of Penn State University in State College, Pennsylvania. Neither, he said, does another planet in the same solar system, known as Gliese 581d, announced in 2009—less clearly hospitable to life, but still once seen by some astronomers as a possible place to find aliens. ... What's happening, they say, is that magnetic disturbances on Gliese 581's surface — starspots — are altering the star's spectrum in such a way that it mimics the motion induced by a planet. The star itself rotates once every 130 days, carrying the starspots with it; the disputed planets appeared to have periods of almost exactly one half and one fourth of the 130-day period. When the scientists corrected for the starspot signal, both planets disappeared.
Science

Oklahoma's Earthquakes Linked To Fracking 154

An anonymous reader writes Oklahoma has already experienced about 240 minor earthquakes this year, roughly double the rate at which California has had them. A recent study (abstract) has now tied those earthquakes to fracking. From the article: "Fracking itself doesn't seem to be causing many earthquakes at all. However, after the well is fracked, all that wastewater needs to be pumped back out and disposed of somewhere. Since it's often laced with chemicals and difficult to treat, companies will often pump the wastewater back underground into separate disposal wells. Wastewater injection comes with a catch, however: The process both pushes the crust in the region downward and increases pressure in cracks along the faults. That makes the faults more prone to slippages and earthquakes. ... More specifically, the researchers concluded that 89 wells were likely responsible for most of the seismic activity. And just four wells located southeast of Oklahoma City were likely responsible for about one-fifth of seismic activity in the state between 2008 and 2013."
NASA

NASA Approves Production of Most Powerful Rocket Ever 146

As reported by the Sydney Morning Herald, NASA has given a green light to the production of a new motor, dubbed the Space Launch System, intended to enable deep space exploration. Boeing, prime contractor on the rocket, announced on Wednesday that it had completed a critical design review and finalized a $US2.8-billion contract with NASA. The last time the space agency made such an assessment of a deep-space rocket was the mighty Saturn V, which took astronauts to the moon. ... Space Launch System's design called for the integration of existing hardware, spurring criticism that it's a "Frankenstein rocket," with much of it assembled from already developed technology. For instance, its two rocket boosters are advanced versions of the Space Shuttle boosters, and a cryogenic propulsion stage is based on the motor of a rocket often used by the Air Force. The Space Frontier Foundation, an advocacy group and frequent NASA critic, said Space Launch System was "built from rotting remnants of left over congressional pork. And its budgetary footprints will stamp out all the missions it is supposed to carry, kill our astronaut program and destroy science and technology projects throughout NASA."
Space

What Came First, Black Holes Or Galaxies? 76

StartsWithABang (3485481) writes "It was one of the most hotly contested questions for decades: we first expected and then found supermassive black holes at the centers of practically all large galaxies. But how did they get there? In particular, you could imagine it happening either way: either there was this top-down scenario, where large-scale structures formed first and fragmented into galaxies, forming black holes at their centers afterwards, or a bottom-up scenario, where small-scale structures dominate at the beginning, and larger ones only form later from the merger of these earlier, little ones. As it turns out, both of these play a role in our Universe, but as far as the question of what came first, black holes or galaxies, only one answer is right."

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