"Using the Chandra X-ray Observatory his team took the most detailed images ever of Jupiter at X-ray wavelengths, and they discovered an auroral "hot spot" that periodically spews out high-energy pulses every 45 minutes.

The origin of this X-ray heartbeat has left theorists scrambling to determine its cause."

"A pulsating hot spot of X-rays has been discovered in the polar regions of Jupiter's upper atmosphere by NASA's Chandra X-ray Observatory. Previous theories cannot explain either the pulsations or the location of the hot spot, prompting scientists to search for a new process to produce Jupiter's X-rays."

"One possibility is that heavy ions among the particles flowing out from the Sun as the solar wind are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from pole to pole in an oscillating motion that might explain the pulsations."

Read on at Chandra & Sky and Telescope

An instrument on NASA's Mars 2001 Odyssey spacecraft has estimated the amount of cosmic rays hitting Mars - so they can determine how unsafe it might be if humans ever land there. Mars has less atmosphere than Earth, and therefore less protection from cosmic rays

Mars - Rems per Year On Earth we typically receive 0.05 rems per year. radiation workers have a safety limit or 5 rems per year. Astronauts in space receive roughly 75 rems per year, although a solar flare could deliver 4,000 rems to the skin and 200 rems to internal organs in a single deadly dose. On Mars a human would receive between 10 & 20 rems per year.

Mars - Hits per Cell Nucleus The estimated average number of times per year each cell nucleus in a human there would be hit by a high-energy cosmic ray particle. On Mars it is between 2 & 8 hits per cell nucleus per year.