Pale Blue Dot

The "Pale Blue Dot" is a photograph of planet Earth taken in 1990 by the Voyager 1 space probe from 3.7 billion miles from Earth, as it was leaving the Solar System after it had completed its primary mission of photographing the outer planets. Earth is shown as a tiny dot (middle right), prompting cosmologist Carl Sagan, who was involved with the Voyager project and made the request to have the Voyager point its camera to Earth, to remark:

From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, 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 – 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 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 this pixel on the scarcely distinguishable inhabitants of some other corner. 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.

The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. 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 with one another and to preserve and cherish the pale blue dot, the only home we've ever known.

—Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space, 1997 reprint, pp. xv–xvi

The location of the Voyager 1 when the photo was taken. 

Earth (in blue circle).

Voyager Spacecraft Nears Interstellar Space

The Voyager 1 space probe, launched by NASA in 1977 to study the outer Solar System and interstellar medium, is now more than 11 billion miles from the sun (the farthest man-made object from Earth), poised to become the first human-made object to reach interstellar space, as it is currently in the outer layer of heliosphere, a sort of bubble of charged particles in the space surrounding the Solar System.

The Voyager 1 and Voyage 2 were the first space probes to provide detailed, colorful images of Jupiter, Saturn, Uranus, Neptune, and their moons. And what fantastic images were these! I remember marveling at these images from the outer planets and their many diverse moons.

Jupiter's Great Red Spot and cloud bands in detail. The white oval storm below the Great Red Spot is the same diameter as the Earth.  

A montage of images taken be Voyager probes.

A volcano erupts on Io, the hyper-active moon of Jupiter. 

Each Voyager probe carries an audio-visual disc in the event that either spacecraft is ever found by intelligent life-forms from other planetary systems. The discs carry photos of the Earth and its lifeforms, a range of scientific information, spoken greetings in many languages, a medley of sounds and songs.  Though it will take about 40,000 years for the probes to pass within 1.6 light years from another star, the placement of the discs symbolize the humankind's mark into the unknown -- where science fact meets science fiction. 

For more info: http://voyager.jpl.nasa.gov/index.html

Earthrise

"Earthrise" is another influential space image, taken by an Apollo 8 astronaut in 1968 during the first manned orbit of the moon.  Instead of the usual and familiar sunrise and moonrise seen by humans for tens of thousands of years, this is the first color image of the Planet Earth seen rising vis-a-vis another planetary body. The blue and colorful planet, teeming with life and activities, contrasts with dull and silent moon's surface, but it also signified poignant fragility of the planet, ushering in environmental and ecological concerns and care for our home planet.



Here's another image of Earthrise -- this time a HD video taken by Kaguya, the Japanese lunar orbiting spacecraft, in 2007. 

Note: Earthrise is a phenomenon seen only from satellites or spacecrafts that travel around the Moon, as it cannot be observed by a person who is on the Moon as s/he can always see the Earth at the same position -- the same reason that we cannot see the "dark side of the moon" from here.

The Farthest Image of the Universe

Let's start with this one, which I think is the most profound image ever taken by humankind -- the deepest optical image (thus faintest and farthest) of the known universe, called the eXtreme Deep Field, or XDF, compiled in 2012.  The observable universe is 13.7 billion years old, and the XDF reveals galaxies that span back 13.2 billion years in time, when they were young and forming. Thus the light captured in this photo travelled 13.2 billion years for us to decipher and marvel at.

This amazing photo was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a tiny patch of sky, as seen above in comparison to the visual size of the moon.  This illustrates the enormous, mind-boggling entity that surrounds us and our tiny and humble presence within that universe, as there are more than 170 billion galaxies in the observable universe and each galaxy contains millions to trillions of stars. This picture is really worth "billions and billions of stars."

More info: http://www.nasa.gov/mission_pages/hubble/science/xdf.html

The Beginning

This is the beginning of "H.K.'s Musings" -- a blog chronicling and interpreting H.K.'s interests and ruminations in cosmology, nature, cinema, cuisine, travel, jazz, photography, culture, art, science, architecture, history, et cetera. Let the explorations begin.