Probe spots the dwarf planet for the first time
False-color images from New Horizons, animated to show Pluto’s movement. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
New Horizons, NASA’s Pluto-bound craft, just passed an important milestone (kilometerstone?). As reported by NASA,
The New Horizons team got a faint glimpse of the mission’s distant, main target when one of the spacecraft’s telescopic cameras spotted Pluto for the first time.
The Long Range Reconnaissance Imager (LORRI) took the pictures during an optical navigation test on Sept. 21–24, and stored them on the spacecraft’s data recorder until their recent transmission back to Earth. Seen at a distance of about 4.2 billion kilometers (2.6 billion miles) from the spacecraft, Pluto is little more than a faint point of light among a dense field of stars. But the images prove that the spacecraft can find and track long-range targets, a critical capability the team will use to navigate New Horizons toward 2,500-kilometer wide Pluto and, later, one or more 50-kilometer sized Kuiper Belt objects.
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In an extensive follow-up article, the BBC discusses some of the developments that have taken place since I last discussed the apparent poisoning of Alexander Litvinenko. The offices of a security and risk management company that Mr. Litvinenko had visited has traces of radiation; also, radiation has been found in the offices of Boris Berezovsky, a friend that Mr. Litvinenko had visited that day.
In addition, 1,121 people have called a helpline arranged by the health service; 68 cases were followed up and eight people have been referred for specialty testing, according to the BBC. Test results should be available in the next few days, New Scientist reports.
In a separate article, Rob Edwards of New Scientist discusses the difficulties and peculiarities of polonium-210 poisoning:
Nick Priest, an expert on polonium-210 who used to work with the UK Atomic Energy Authority, argues that it would be no easy matter to obtain enough to kill someone. “I find it difficult to believe that it was sourced in the UK or the European Union,” he said.
“All the signs point to it being a sophisticated operation,” he told New Scientist. “You would need a reactor capable of producing and irradiating materials and a radiochemical laboratory.”
However, once obtained, it appears it would be a simpler matter to actually administer the poison.
In solution as a citrate, nitrate or other salt, it could be rendered tasteless and easy to slip into a drink, [Mr. Priest] says. Up to 50% would be taken up by blood and tissue fluid, delivering serious radiation doses to different parts of the body.