Astronomy Jupiter: A cloudy mirror for the Sun?

Discussion in 'Astronomy' started by mscbkc070904, Mar 8, 2005.

  1. mscbkc070904

    mscbkc070904 Premium Member

    Astronomers using the European Space Agency's XMM-Newton telescope have discovered that observing the giant planet Jupiter may actually give them an insight in to solar activity on the far side of the Sun! In research reported in the most recent edition of Geophysical Research Letters, they discovered that Jupiter's x-ray glow is due to x-rays from the Sun being reflected back off the planet's atmosphere.

    Jupiter is an intriguing object when viewed in x-rays; it has dramatic x-ray auroras at the poles and a variable x-ray glow from near the equator. Researchers had theorised that these x-rays from the equatorial regions of Jupiter, called disk x-rays, were controlled by the Sun. In November 2003, during a period of high solar activity, they observed Jupiter.

    "We found that Jupiter's day-to-day disk x-rays were synchronised with the Sun's emissions," says Dr Anil Bhardwaj, from NASA Marshall Space Flight Centre and lead author on the paper. "Unfortunately, we missed a relatively large solar flare during the 3.5-days observation due to the perigee passage of the XMM-Newton". "But, still we were lucky; particularly clear was a signature of a moderate solar flare that went off during the observing period - there was a corresponding brightening of the Jovian disk x-rays", says Anil Bhardwaj.

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