Space & Astronomy

Mystery surrounds X-rays streaming from Pluto

By T.K. Randall
November 10, 2016

Image: New Horizons Photograph of Pluto (2015)
Credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / (PD) Pluto might be small, but when New Horizons obtained the first ever close-up views of the dwarf planet back in 2015 it revealed a world filled with surprises that continue to intrigue to this day.

One of the most recent peculiarities about Pluto has been the discovery that it is producing a mysterious stream of X-rays that physicists have so far been unable to conclusively explain.

The phenomenon was first picked up by astronomers using the Chandra X-ray telescope.

X-rays are typically produced on planets and comets when the solar wind interacts with their magnetic field or with neutral gas atoms in their atmosphere.In this case however, Pluto has no measurable magnetic field and its atmosphere, which is extremely thin, has been disappearing much more slowly than anyone had expected.

"We naively thought Pluto might be losing its atmosphere at the same rate as [some] comets," said planetary astronomer Carey Lisse. "We knew comets make X-rays, so we hoped that Pluto did too."

The leading theory right now is that the X-rays are being produced by the solar wind interacting, not with Pluto, but with a long tail of methane gas being dragged along behind it.

"It's a very puzzling finding," said astrophysicist Konrad Dennerl. "I'm not fully convinced."

Source: Science News

Tags: Pluto