THE SOUTHWORTH PLANETARIUM

70 Falmouth Street  Portland, Maine 04103

(207) 780-4249   usm.maine.edu/planet

43.67° N 70.27° W

Founded January 1970

2022-2023: XCVII

Sunrise: 5:07 a.m.

Sunset: 8:10 p.m.

Civil twilight begins: 4:33 a.m.

Civil twilight ends: 8:44 p.m.

Sun's host constellation: Taurus the Bull

Lunar phase: Waxing crescent (32% illuminated)

Moon rise: 10:01 a.m.

Moon set: 1:20 a.m. (5/26/2023)

Julian date: 2460089.29

"The Universe is transformation; life is opinion."

-Marcus Aurelius

THE DAILY ASTRONOMER

Thursday, May 25, 2023

The Geysers of Enceladus

So many of us want life.

Well, more precisely, so many of us want life to abound in the Universe. We want the benevolent, hammer-headed squat-bodied ETS with the midnight black eyes and luminescent fingertips. We want the frantic little Galea-sporting maniac running around the Martian surface as it strives to annihilate Earthlings. We want the phosphorescent ferns, iridescent pteradons, winged serpents, clairvoyant slime molds, hyper-intelligent, toga-clad cosmic philosophers contorting space-time with delta-brain wave emissions. Heavens above, we even want the cloak-covered emperors,the homicidal twerps encapsulated in inverted tin-bins and those malevolent, mucus-coated menaces impregnating hapless astronauts. Everyone and everything from the uber-evolved to the pathetically prokaryotic anywhere and everywhere out in that bustling, unsleeping, galactic megalopolis.

As of now, of course, we only know of one life-bearing world and we're living on it. However, our isolation could very well be illusory. It is possible that Earth is just one of billions of living planets or it might be unique. We just don't know, yet. However, finding evidence of life elsewhere in the solar system might indicate that life could form in any place where conditions are conducive to its development.

So, we're eagerly scrutinizing Enceladus, the ice-encrusted ocean moon in orbit around Saturn. Of all the cold moons in orbit around the distant planets, Enceladus is one the few places in our little niche where life could exist. Although we haven't found direct evidence of such life, yet, this 313-mile-wide Saturnian satellite seems promising principally because of its geysers.

These watery outbursts, first detected in 2005 by the Cassini probe, contain ammonia,methane and carbon dioxide: material necessary for life's development. In fact, these chemicals might be produced as metabolic byproducts of life tucked away within the moon's subterranean ocean. These geysers are not only laden with life-sustaining molecules, they are also immensely powerful. The Webb Telescope recently observed that some of these geysers extend for hundreds of miles off the moon's surface: a distance greater than its diameter. A considerable amount of heat and pressure are necessary to produce such jets.

There is even a proposed NASA mission entitled the Enceladus Orbilander that would both orbit Enceladus and deploy a lander onto its surface. Both the orbiter and probe would be designed to search for evidence of any life within the geysers. While we don't believe that highly advanced life forms would be lurking under the ice, it is possible that some sort of alien beings, even microscopic ones, could be thriving in that ocean located about one billion miles from the Sun. Splendid news for those who believe that our Universe is not only more creative than we imagine, but far more creative than we can imagine.

*Here's something to consider. Let's assume that the Universe contains ten billion life-bearing worlds. That is no small number. After all, ten billion seconds equals 320 years. In order to have this many living worlds, only 0.000000000001% of stars would have to harbor a life-bearing planet. This minuscule fraction would please even the most pessimistic among us.

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