Ian Sample “Rise in space junk could provoke armed conflict say scientists” http://www.theguardian.com/science/2016/jan/22/rise-in-space-junk-could-provoke-armed-conflict-say-scientists
地球軌道上で増加するロケットの破片などの「宇宙のごみ」が政治的・軍事的危険物になりつつあるという、露西亜科学アカデミーのVitaly Adushkin氏の研究；
Space agencies in the US and Russia track more than 23,000 pieces of space junk larger than 10cm, but estimates suggest there could be half a billion fragments ranging from one to 10cm, and trillions of even smaller particles.The junk poses the greatest danger to satellites in low Earth orbit, where debris can slam into spacecraft at a combined speed of more than 30,000mph. This realm of space, which stretches from 100 to 1200 miles above the surface, is where most military satellites are deployed.
さて、
In a report to be published in the journal Acta Astronautica, Vitaly Adushkin at the Russian Academy of Sciences in Moscow writes that impacts from space junk, especially on military satellites, posed a “special political danger” and “may provoke political or even armed conflict between space-faring nations. The owner of the impacted and destroyed satellite can hardly quickly determine the real cause of the accident.”Adushkin adds that in recent decades there have been repeated sudden failures of defence satellites which have never been explained. But there are only two possibilities, he claims: either unregistered collisions with space debris, or an aggressive action by an adversary. “This is a politically dangerous dilemma,” he writes.
The warning comes after an incident in 2013 when a Russian satellite, Blits, was disabled after apparently colliding with debris created when China shot down one of its own old weather satellites in 2007. The Chinese used a missile to destroy its satellite, an act that demonstrated its anti-satellite capabilities, and left 3,000 more pieces of debris in orbit.
According to the report, the amount of debris cluttering low Earth orbit has risen dramatically in half a century of spacefaring. Without efforts to clean up the space environment, Adushkin warns of a “cascade process” in which chunks of debris crash into one another and produce ever more smaller fragments.
Alexandra Witze “Evidence grows for giant planet on fringes of Solar System”
http://www.nature.com/news/evidence-grows-for-giant-planet-on-fringes-of-solar-system-1.19182
「９番目の惑星」*1に関する『ネイチャー』の報道。当の論文は『ネイチャー』に掲載されたのではないのだが。
