Thursday, May 1, 2008

Polar coronal jets of the Sun - imaged in stereo by STEREO

These are the most spectacular images published in a scientific paper from the STEREO mission: the hi-res pictures (on pages 10 and 13 of this PDF version!) show polar coronal jets from viewpoints 11° apart. The stereo view reveals "the 3D dynamics and morphology of a well-defined EUV coronal jet for the first time. Triangulations of the jet's location in simultaneous image pairs led to the true 3D position and thereby its kinematics. [...] Helical structure is the most important geometrical feature of the jet which shows evidence of untwisting. The jet structure appears strikingly different from each of the two STEREO viewpoints: face-on in the one viewpoint and edge-on in the other. [...] The clear demonstration of twisted structure in polar jets compares favorably with synthetic images from a recent MHD simulation of jets invoking magnetic untwisting as their driving mechanism." And this isn't even the first science result making use of the unique stereo vision of the STEREO mission.

In other news here are Mercury on April 29th, old Cassini views of the Saturn storm that has been active since last November (and now been joined by another storm NASA fails to mention), ionospheric data fed into Google Earth and a scientific paper on the Galaxy Zoo project. "The project has obtained more than 40,000,000 individual classifications made by ~100,000 participants," the authors marvel: "We find that Galaxy Zoo results are consistent with those for subsets of SDSS galaxies classified by professional astronomers, thus demonstrating that our data provides a robust morphological catalogue."

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