Galileo would have been a blogger

Observing with his 20-power telescope in late 1609 and early 1610, writing a letter about what he observed on 7 January 1610, and publishing in book form a first ever description of phenomena such as Jupiter's moons, just 9 weeks later.

Galileo continued his observations of the new planets [moons] as the printing progressed. His last observation is dated 2 March 1610.

On 13 March 1610 he sent an unbound copy to the Tuscan court, with a properly bound copy following on 19 March 1610. The book was Sidereus Nuncius, usually translated as Sidereal Messenger, although I prefer the more evocative Starry Messenger.

How's that for time between observations and publication.

The book is a short and clear read, full of excitement.
I was inspired to read it after hearing quotes from it in the amazing Tafelmusik Galileo Project.
It's a pleasure to be able to blog about it, almost 400 years later.

Accordingly, on the seventh day of January of the present year 1610, at the first hour of the night, when I inspected the celestial constellations through a spyglass, Jupiter presented himself. And since I had prepared for myself a superlative instrument, I saw (which earlier had not happened because of the weakness of the other instruments) that three little stars were positioned near him--small but yet very bright.