Personally speaking, the blogs I enjoy most are those with content other than just multiple images of a well-twitched bird: I enjoy reading about things of which I have little or no knowledge (leaf mines, micro-moths, hover flies) or no chance of seeing in the flesh myself (walrus, Andean Condor, Wallcreeper etc.) I also find the occasional personal sagas of some well-known bloggers to be compelling reading at times: whether it's a domestic crisis, a foreign holiday or a newly-discovered restaurant, they can be very absorbing.
My reasons for posting astronomical blogs are quite straight forward:
1) I'm an astronomer and it's my blog!
2) I usually only post details of scarce or aesthetically interesting celestial occurrences such as eclipses, occultations, conjunctions and planetary transits.
I concede you'd have to be a bit of a space-nerd like me to appreciate the images of the asteroid Vesta I posted recently, but I don't think you have to be an Astronomer to appreciate seeing Jupiter and its four largest satellites, which you can easily achieve with a birding 'scope. (At the moment, it's just above the western horizon at 10pm, right next to the Moon) And I'm sure the sight of Saturn's rings and its largest satellite Titan are worth a look: it'll be above the southern horizon at the same time. The incredibly bright red 'star' in the south-east? That's Mars! The even-brighter object that follows the Sun to the horizon just after it sets in the west? Venus!
So, notwithstanding the comments of my acquaintance. I'll carry on giving astronomical 'heads ups' to those of you who haven't abandoned blogs for tweets!
|Jupiter, with its satellites Io, Callisto, Ganymede and Europa|
|Crescent Venus in the twilight|
|Partial eclipse of the Sun from Strumpshaw.|