Plants of a summer morning

Today will seem long, in that sunset comes latest, at least for places about latitude 40° north.

The reasons why this and the earliest sunrise (June 14) do not coincide with the solstice (June 20), and the pattern of variation with latitude, are set out in our page about latest and earliest sunrise and sunset.

Though sunrise was earliest a week ago, it’s still pretty early. And interesting.

See the end note about enlarging illustrations. Arrows through the moving bodies show their movement (against the starry background) from 2 days earlier to 2 days later. Moon and Sun are exaggerated 4 and 2 times in size. Saturn is exaggerated 150 times in size, to show the current attitude of its rings. There will be little difference a day later, except in the position of the Moon.

The Moon “as signpost” (to quote a section of the Astronomical Companion) crosses our orbit ahead of us, therefore appears half-sunlit, and is near the point that is now “Earth’s direction of motion.” Which in turn is close to the equinox point, where the Sun’s path crosses the equator, about 90° back from where the Sun now is.

The Moon will pass about half a degree south of Saturn today at 16h Universal Time, and Neptune, June 28 at 9 UT, occulting both of them as seen from some parts of Earth.

A plant is not a wanderer

A plant is not a planet, though typing one of those words when I intending the other is a common error.

The word “solstice” suggests a great set of words containing an element st-, a root in the proto-Indo-European language, with a meaning of “standing, stability”; and a similar bunch from sed-, “sit.” My attempt to list those words should sometime, in view of your comments, be corrected and amplified.

The sky scene suggests another forest of words, but is it one tree or two, with related though apparently opposite meaning?

Plant, flat, plain, plan, place, plate, the region Latium and hence the name of the language Latin, go back to roots pele- and plat- that had a meaning of “flat” or “spreading” and were themselves surely related.

Planet, by contrast, means “wanderer,” Greek planêtês, from the verb with stem plana-. The root of this is uncertain; some suggest, others doubt, that it could be an extension of the sense of “spreading.”

Latitude, lateral. Another curious twist: they are attributed not to the plat- but to the st- root with its extension stel-.

Mixed Metaphors of the Election Season Department

Labour landslide projected with dozens of Tory-held seats on knife-edge. -: Guardian headline, June 20

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This weblog maintains its right to be about astronomy or anything under the sun.

ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor.

One way: right-click, and choose ”View image” or ”Open image in new tab”, then enlarge. Or choose ”Copy image”, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.

Sometimes I make improvements or corrections to a post after publishing it.  If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version. Or, if you click ‘Refresh’ or press function key 5, you’ll see the latest version.