The solar system has become humankind’s new backyard. It
is the playground of robotic planetary spacecraft that have
surveyed just about every corner of this vast expanse in
space. Nowadays, every schoolchild knows what even the
farthest planets look like. Fifty years ago, these places could
only be imagined, and traveling to them was the realm of
fiction. In just this short time in the long history of the
human species we have leapt off the surface of our home
planet and sent robotic extensions of our eyes, ears, noses,
arms, and legs to the far reaches of the solar system and
beyond.
In the early days of the 20th century, we were using airplanes
to extend our reach to the last unexplored surface
regions of our own planet. Now 100 years later, at the beginning
of the 21st century, we are using spacecraft to extend
our reach from the innermost planet Mercury to the outmost
planet Neptune, and we have a spacecraft on the way
to Pluto and the Kuiper Belt. Today, there are telescopes
beyond imagination 100 or even 50 years ago that can image
Pluto and detect planets around other stars! Now, Sol’s
planets can say “we are not alone”; there are objects just like
us elsewhere in the universe. As humanity’s space technology
improves, perhaps in the next 100 years or so human
beings also may be able to say “we are not alone.”
When I was a kid 50 years ago, I was thrilled by the
paintings of Chesley Bonestell and others who put their
imagination on canvas to show us what it might be like “out
there.” Werner Von Braun’s Collier’s magazine articles of
1952–1954 superbly illustrated how we would go to the
Moon and Mars using new rocket technologies. Reading
those fabulous articles crystallized thoughts in my young
mind about what to do with my life. I wanted to be part of
the adventure to find out what these places were like. Not
so long after the Collier’s articles appeared, we did go to the
Moon, and pretty much as illustrated, although perhaps not
in such a grand manner.We have not sent humans toMars—
at least we haven’t yet—but we have sent our robots to Mars
and to just about every other place in the solar system as
well.