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Pluto Is Emitting X-Rays (digitaltrends.com)
An anonymous reader quotes a report from Digital Trends: Scientists have noticed the tiny trans-Neptunium object emitting X-rays, which, if it is confirmed, is both a baffling and exciting discovery. Carey Lisse and Ralph McNutt from Johns Hopkins University Applied Physics Laboratory and a team of colleagues detected the X-rays by pointing the Chandra X-Ray Obervatory telescope in Pluto's direction four different times between February 2014 and August 2015. Seven photons of X-ray light were detected during these observations, confirming the team's hypothesis that the dwarf planet is detectable on the X-ray spectrum, potentially due to the presence of an atmosphere. Their findings have been published in the scientific journal Icarus. Why is this such a big deal? First of all, it would challenge what scientists have previously believed to be true of Pluto's nature. Until now, the popular description of the dwarf planet is as a tiny ball of frozen rock slowly meandering around the sun some 3.6-billion miles away. One of the possible explanations for why Pluto is emanating X-rays would be that the high energy particles emitted by the sun are stripping away and reacting with Pluto's atmosphere, producing the X-rays that are visible to Chandra. There are other potential explanations, such as haze particles in Pluto's atmosphere scattering the sun's X-rays are possible, though unlikely given the temperature of the X-rays observed. It is also possible that these X-rays are actually bright auroras produced by the atmosphere, but that would require Pluto to have a magnetic field -- something that would have been detected during New Horizon's flyby, yet no evidence of one was found.
"I appreciate that "dwarf" planet doesn't sound too PC but I do wonder whether we should reserve the adjective "tiny" for items too small for their own gravitational mass to pull them into a sphere."
If you're going to invent your own classification system, then I propose we make everyone feel better by classififying them as follows:
'Tall' - A body too small to form a sphere.
'Grande' - Forms a sphere but does not clear its orbit.
'Venti' - Clears its orbit.
'Trenta' - Gas giants.
It's a trans-NEPTUNIAN object. Not trans-NEPTUNIUM. Neptunium is an element (Np. Atomic Number 93).
The term was invented so that cis-neptunian objects can spend the rest of their eons apologizing for their existence.