My day started with a discussion of determination of stellar radial velocities by cross-correlation with a weighted mask (as is done in the HARPS pipeline) with Megan Bedell (Chicago). We talked about the subtleties of doing this, when there are partial-pixel shifts and we want answers that are continuous.
There was a substantial phone call today organized by Jonathan Bird (Vanderbilt) to talk about the After-SDSS-IV proposal for use of the 2.5-m telescope and its instruments. We are working on a proposal called Disco to do dense sampling of the Milky Way disk (looking in the infrared through the dust).
By text message, Adrian Price-Whelan (Princeton) and I tentatively decided that we would pursue a paper about wide binaries with the Gaia DR1 T-GAS data that we were exploring yesterday. I really hope we have a paper to write, because it would be fun to be in the first set of papers. Of course Gaia DR1 papers appeared on the arXiv already tonight!
At the end of the day, Sean Solomon (Columbia) gave the Departmental Colloquium, about Mercury and the Messenger mission. It was a great talk, showing that there is water and volatiles on Mercury, as not expected in naive models. At the end, Jasna Brujic (NYU) asked him about life on Mercury and elsewhere in the Solar System. He described the evidence that rocks are thrown from planet to planet and expressed the view (also held by me) that it is quite likely that there is life elsewhere in the Solar System. That made me happy!