This blog reported in depth about a possible weak 2nd outburst of comet Holmes in late January - and now THE ASTRONOMER Electronic Circular No 2430 has news about a third outburst in progress! "Images and photometry by several observers [...] suggest that comet 17P/Holmes has shown a further mini-outburst, which appears to have initiated on 2008 March 7," we learn: The R-magnitude of a 10 arcsec square aperture, equivalent to a physical aperture of 22000 km at the comet, went up from 16.1 to 15.7. Which for Mark Kidger and Richard Miles means a lot: "The three events detected so far have taken place at 44.6±0.6, 89.5±0.6 and 135.1±0.8 days after the initial outburst on 2007 October 23.7, giving a mean interval of 45.0±0.5 days determined from a least squares fit. The correlation coefficient of the fit is r2=0.99997. It is likely that this periodicity corresponds to the rotation period of the nucleus whereby the same area is activated when receiving insolation and thus it is concluded that 17P/Holmes is a very slow rotator, comparable to 29P/Schwassmann-Wachmann 1, which from Spitzer observations of its jets [...] appears to rotate with a period of 60 days or more."
In other news the 2008 ED8 vs. EZ7 mystery remains unsolved, but the 2nd NEA is now close. • The first ATV has been seen at +0.5 mag one day after its Kourou launch. • And claims about connections between galactic cosmic rays and Earth's climate take another hit - from astrophysics itself.