Songs in Blue and Green

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Deputy Dog, working from a variety of sources, put together earlier this month a collection of 11 breathtaking photos of the Earth from space. My favorite happens to be this one, a capture of the transit of the moon’s shadow across our planet during the solar eclipse of August 11, 1999, taken from the space station Mir:

It could rightly be said that, in this modern age, our civilization is struggling to come to grips with the achievements of science and the exponential growth of our species in ways personal and societal, in terms of today and of the outlook for the decades and centuries which expand before us in our imaginings of the tapestry of forever. These are disorienting times. It is good for us, then, I think, to spend whiles with images such as these. I am reminded of Carl Sagan’s apt commentary from a 1994 Cornell lecture, which he paired with the following photo, then (and probably still) the most distant photograph of Earth, taken by Voyager 1 in 1990 at a distance of four billion miles:

“We succeeded in taking that picture, and, if you look at it, you see a dot. That’s here. That’s home. That’s us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.
The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity — in all this vastness — there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It’s been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we’ve ever known.”

Those are severely illuminating words from one of the greatest of modern minds.

55 Cancri – A Home Away from Home?

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Skymania News reports that astronomers working at California’s Lick Observatory have isolated the identity and certain characteristics of an Earth-like planet orbiting 55 Cancri, a star 41 light years distant from our own Sun and remarkably similar in physical characteristics such as core composition, spectrum, and temperature.

The discovery of this planet, approximately 45 times the mass of Earth and located within its star’s “habitable zone”—the orbital stratum in which conditions for the formation of Earth-like life would be optimal—demonstrates concretely what astronomers and philosophers have speculated for centuries: that our own star system, while quite special to us, is far from categorically unique.

While it would certainly be “jumping the gun” to assume that such a planet harbors life simply because of the existence of an optimal configuration, the most profound implication of the discovery—in harmony with other discoveries about extrasolar worlds which continue to surface as technology and techniques improve—is that, in its ability to support life, our own world is hardly the beneficiary of a singular providence of chance or “design.”

It is the fifth planet to be identified in orbit around the star 55 Cancri, a star very similar in type and age to our own Sun, making it a virtual twin of our own solar system.

The star, which is dimly visible to the naked eye in the constellation of Cancer, now holds the record for the number of worlds in orbit, after our own Sun. It lies just 41 light-years away – right on our cosmic doorstep.
Scientists said the new planet is 45 times the mass, or size of the Earth, and has a year 260 days long – the time it takes to orbit 55 Cancri. It was found by measuring the tiny wobble it causes to the star as it orbits. Detecting this was a triumph for the astronomers and took them 18 years of study from Lick Observatory, California, because it had to be separated from the effects of the other planets.

The planet is 72.5 million miles from 55 Cancri, a little less than the distance of the Earth from the Sun, but at an ideal distance for the warmth that life as we know it would need to exist.

Geoff Marcy, of the University of California, said last night: “The discovery has me jumping out of my socks. We now know that our own Sun and its family of planets is not unusual.”

He said that if there is a moon going around this new planet, it would have a rocky surface. Water could form lakes or seas and produce the conditions for life to begin. But he added: “Then all bets are off as to how life could evolve on that moon.”

Fellow discoverer Debra Fischer, of San Francisco State University, said she expected that other Earth-like planets could exist in the star’s habitable zone.

She said: “I bet that gap is not empty.”

She added: “55 Cancri is very much like our own sun. It is about the same size and the same age. It is a solar system that is packed with planets. It has profound implications for how we search for Earth-like planets.”

She went on: “The gas-giant planets in our solar system all have large moons. If there is a moon orbiting this new, massive planet, it might have pools of liquid water on a rocky surface.”

A Family Moment

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Just a bit ago, I stepped outside to notice that a full Moon, Mars, and Venus were all in the sky, and aligned across it from west to east in a nearly perfect line.

Considering the difference in the distance between Earth and Mars and the distance between Earth and the Andromeda Galaxy, I’d say that’s quite the family moment.

Soon Dad will come stumbling and grumbling over the eastern horizon, and it’ll be time to cook breakfast.

By the Light of the Bloody Moon

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Check out Aussie photographer Steve Selbst’s incomparable capture of the moon during last month’s total eclipse (pic links to artist’s page on Flickr).

The eclipse of August 28, 2007 was especially noteworthy because of its unusual length, clocking in at over an hour and a half in the depths of the shadow. It was not visible throughout Europe, Africa, and western Asia; in the Americas we caught it just as the moon was setting and the sun was coming up in the morning, while east Asia and Australia had been treated earlier, at moonrise. No one really got to see this eclipse in full glory, but it was very interesting in its orientation near the horizon, nonetheless.

The next total eclipse of the moon will occur on February 21, 2008. Its totality will last only about 51 minutes, but it will be at least mostly visible to the entirety of the world except east Asia and Australia.

If you caught wind of those ridiculous emails claiming that, on August 27, the planet Mars was going to be so close to Earth as to appear “about the same size as the moon,” et cetera, ad nauseum, take heart—snopes.com has a thorough exposé on the subject. Mars did come unusually close to Earth in August of 2003, but even at such a unique perigee, the red planet still appeared as little more than an auspiciously bright point in the heavens. If you ever do happen to catch a moon-sized Mars in the sky, well . . . it’s probably fair warning to have that last beer for old times’ sake.