Chet Raymo, "Nebula"
"Nebula"
by Chet Raymo
"The APOD (Astronomy Picture of the Day) on Columbus Day was the planetary nebula known as Abell 39, an almost perfectly spherical shell of gas blown off by a Sun-like star in the final throes of its life. The name, planetary nebula, has nothing to do with planets per se. The name derives from a time- late 18th century- when these frequently disk-shaped objects, seen with less resolution than today, appeared planet-like in a telescope.
Click image for larger size.
You can find dozens of images of planetary nebulae on the APOD or Hubble web sites, but few are as beautifully symmetric as Abell 39, a lovely soap bubble in space. This "soap bubble" is 5 light-years across. If that were the dying Sun at the center of the nebula, the shell of gas would reach half-way to our nearest neighbor, Alpha Centauri. The bubble is 7,000 light years away, in our own Milky Way Galaxy.
This will be the fate of our own star in 5 billion years or so– outer layers blown off into space, then collapse into a white dwarf, a burned-out star with the remaining mass crushed by gravity to the sixe of the Earth (you can think of it roughly as atom-against-atom). Then a slow extinction, leaving a bubble behind that will slowly disperse into the interstellar medium.
Anyway, it was a fitting image. I spent the holiday blowing off my own late-life excess of exhausted matter. A back bedroom upstairs filled to overflowing with the accumulated artifacts of a lifetime. Personal journals. Book manuscripts, including embarrassingly bad books I wrote before I had any idea how to write. Dozens of magazines and journals in which I had an essay or book review. Reviews of my own books. Movie scripts. Out-take tapes from Frankie Starlight. Thousands of xeroxed Globe columns. A hundred floppy disks. Obsolete software disks and manuals. Defunct laptops, going back to the first Mac laptop that appeared on the market. A dot-matrix printer. Photographs. Drawing tools. Tons of correspondence from the days when correspondence was on paper. Stuff I do not even remember. It was like an archeological dig.
What to save? What to throw in the dumpster? Bag after bag went out in the trash, my blown-off bubble, the planetary nebula of my life. Saved whatever I presumptuously thought the kids or grandkids might someday find nostalgic, my white dwarf core, a bedroom full of one man's life squeezed into a tiny closet.”
- http://blog.sciencemusings.com/
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