Tuesday, May 21, 2013

A "Dizzying Sprawl of Suns and Planets"

"Using NASA's planet hunting Kepler spacecraft. astronomers have discovered 2,740 planet candidates orbiting 2,036 other suns in a search for earth-sized worlds. The search began in 2009. Kepler monitors a rich star field for planetary transits which cause a slight dimming of the starlight when a planet crosses the face of its star..."

"...In this remarkable illustration created by Jason Rowe of NASA's Kepler Science Team, all of Kepler's planet candidates are shown in transit with their parent stars ordered by size from top left to bottom right. Simulated stellar disks and the silhouettes of transiting planets are all shown at the same relative scale, with saturated star colors. Of course, some stars show more than one planet in transit, but you may have to examine the picture at high resolution to spot them all. For reference, the Sun is shown at the same scale, by itself below the top row on the right. In silhouette against the Sun's disk, both Jupiter and Earth are in transit."

- via this Kepler/Nasa page

(Hat-tip to David Darling)


"Each mote of light is a star, as transient in its own magnificent way as the blinking of fireflies. Nothing is permanent, yet billions of the stars embedded in this cosmic swirl have lasted long enough to accrete planets: ponderous, striped gas giants to which Jupiter is but a comma; hot, rocky worlds that mirror Mars, Venus and -- quite probably -- our own Earth.

A "billion" can be a difficult number to truly appreciate, except maybe as an abstract sum of money. Our minds never evolved to deal with such celestial arithmetic. Our rational left-brains, good enough for drafting spreadsheets and tallying the month's bills, are left in embarrassed stupor. I don't know how many stars this galaxy has, but let's say 100 billion. Again: a challenging number. No wonder people made fun of Carl Sagan - speaking of such immensity in merely human language is discomfitingly comical. 

The known universe has over 100 billion galaxies, each hosting its own retinue of stars. Most of these stars have planets; it's statistically inevitable that some of these cradle life. And of these, a fraction almost certainly harbor intelligent life: thinking beings following unguessable agendas. As much as we pretend otherwise, the Earth is not central or even significant in this dizzying sprawl of suns and planets."

- Mac Tonnies, excerpt from a blog entry dated July 16, 2003 from Posthuman Blues, Vol. I, 
2012, Redstar Books

"Even if humanity ultimately takes the dirtnap, the discovery of a living extrasolar planet seems almost inevitable. I wonder what our response will be, gazing at some tantalizing and alien world orbiting another star. What will we have done to ourselves -- and how might our collective predicament color our reception of a confirmed extraterrestrial biosphere?

Although real enough, the new Earth will also play a formative role in our imaginations; it promises to be a liminal frontier as well as an astrobiological focal point -- the locus of new myths, an imaginal haven forged of memes old and new, a distant and beckoning mirror."

- Mac Tonnies, 2006, excerpt from this archived Posthuman Blues blog entry


In the late 1990s, when I first entered cyberspace, one could probably count the number of known exoplanets on one hand. Which is not to say that all the planets on the above chart have been confirmed, but, thanks to Kepler, astronomers have made a quantum leap. That "100 Billion" number that Mac uses in the first quote has now been estimated between 100 - 400 billion... and that estimate refers to exoplanets in the Milky Way galaxy alone!

For those interested, as to the "new Earth" and the "imaginal haven forged of memes old and new" in Mac's second quote, well, not long ago, I was inspired to gather a few mythical memes together regarding a related, and very recent, Kepler discovery. See: When Inner Worlds and Outer Worlds Collide.

(Note: If you click on the RedStar Books link above, you might find a new addition to the roster - hopefully, we'll be hearing about Posthuman Blues, Volume II soon!)

Exoplanet Link List:

Planetary Habitability Laboratory at Arecibo
Exoplanet Orbit Database
European Extrasolar Planets Encyclopaedia
Planet Hunters
Planet Quest