I do enjoy contemplating this famous picture, "Pale Blue Dot", farthest picture of the Earth ever taken. It was shot by Voyager 1 in 1990, while travelling outside our solar system at a velocity of 64000 km/h and a record distance of 6 billion kilometers.
Astronomer Carl Sagan related his thoughts on a deeper meaning of the photograph:
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 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 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 [source]
Regarding Voyager 1, it is still operational and responding to commands broadcast from Earth.
On February 17, 1998, it became the farthest man-made object from Earth, passing Pioneer 10 at 69 AU from the Sun.
Since then, Voyager 1
has been the farthest manmade object from Earth, and there are no
probes predicted to be launched in the next 20 years that will pass the
probe.
On December 3, 2012, NASA scientists announced that Voyager 1
had discovered a previously unknown region of the heliosphere.
Described as a "magnetic highway," here the pressure of the interstellar
medium sweeps back the Sun’s magnetic field and with it many of the
slower moving particles emerging from within the solar system. These are
mixed with faster moving particles entering the solar system from the
interstellar medium. The magnetic field in this newly discovered region
is 10 times more intense than Voyager 1 encountered before the
termination shock. It is expected to be the last barrier before the
spacecraft exits the solar system completely and enters interstellar
space. Voyager 1 is predicted to enter the interstellar medium between 2012–15 [
source].
