In the end, my choice has fallen on the picture clip you can see above. This picture is dear to me, because it was a lucky shot. If you look close enough (well, not even that close), you will notice two quite distinct features of that starry field: a multicolored streak on the left, and a cluster of stars on the right.
A picture can be worth a thousand words. It does contain a large amount of data, and of meta-data too. Here is the data:
- An amateur astronomer should take three seconds to recognize the star field; a non-expert would probably take several minutes to an hour with applications such as the WWT or similar star maps. The tale-telling sign is, of course, the double cluster in Perseus, a magnificent object even with the unaided eye for observers in the Northern emisphere, especially during moonless summer nights.
- From the field of view imaged, the depth of the field (limiting magnitude of stars detectable), the deformation of the star images, and from the presence of a meteor streak, an expert would also be likely to deduce that the picture has been taken with a unguided digital camera, with a 10 to 20 seconds exposure.
- The meteor would then be a huge clue: someone with the passion for meteor showers as myself would be quick to conclude that the picture has been taken between late July and late August. That is because the meteor belongs, almost certainly, to the Perseid stream. An experienced astronomer would be also able to determine the time frame more accurately, because the center of the Perseid radiant moves over time during the month of activity, and it does so in a direction almost orthogonal to the displayed streak: an intersection of the radiant path with the back-propagated streak trajectory would allow a rough but meaningful bracketing of the right date at which the picture was taken.
As for the meta-data, it is easier to figure it out: the picture is there because it is meaningful to me. It tells a story: the story of my love for the stars and amateur astronomy in general; it tells of nights spent shooting endlessly at the starry sky in the hope to capture streaks on CCD; and it ultimately brings a message.
The message is the following: Doing Science, even in the form of giving as modest a contribution to scientific knowledge as the recording of the rate of known meteor showers -an occupation to which I have devoted many sleepless nights in my life- requires patience, perseverance, and devotion. I have found this to be true in all the fields of Science I know anything about. And I hope that you, dear readers -especially those of you who visit my blog for the first time-, will be showing some of that as I flood you with long, complicated explanations of particle physics. Through patience and perseverance -leave alone devotion, for heavens' sake- you might disclose a wonderful world in front of you.