considered himself a scientific historian, one whose mission in
life was to relate geologic and planetary events in a perspective
manner. He brought geologic principles together with the mapping
of planets, resulting in more than three decades of discoveries
about the planets and asteroids of the solar system.
Gene Shoemaker began exploring for uranium deposits in Colorado
and Utah in 1948, and these studies brought him to the many volcanic
features and the one impact structure on the Colorado Plateauthe
Hopi Buttes and Meteor Crater. During the late '50s, he did
his classic research on the structure and mechanics of meteorite
impact, and invented the Branch of Astrogeology within the United
States Geological Survey.
It is said that Gene Shoemaker longed to go to the Moon as an astronaut
and study its geology firsthand. A medical condition kept him from
doing that, but he helped select and train the Apollo astronauts
in lunar geology and impact cratering. He led teams who were investigating
the structure and history of the Moon and developing methods of
planetary geologic mapping from telescope images.
Obviously, Gene was a smart man. He soon figured out how to make
work by combining his knowledge of the geology of the Colorado Plateau
with his love of river running, and came up with the idea of rephotographing
the pictures taken on John Wesley Powell's second exploration
of the Colorado River in 187172. Gene and his partner identified
and rephotographed almost every one of the Powell trip's camera
stations nearly 100 years later. Their work, In the Footsteps
of John Wesley Powell, was published in 1987, and marked the
beginning of the photo matching work that now continues.
Gene Shoemaker died in 1997 from injuries sustained in a car accident
while in Australia studying impact craters. The following year Gene
got his wish to travel to the moon, when a capsule carrying a small
amount of his ashes traveled aboard nasa's Lunar Prospector
spacecraft. On July 31, 1999, after eighteen months of successful
orbital scientific operations, Lunar Prospector was commanded to
crash into the surface of the Moon. At his journeys' end, Eugene
M. Shoemaker became the first inhabitant of Earth to be sent to
rest on another celestial body.
been working around on the Colorado Plateau since 1948. I've had
a long lasting love affair with the Green and Colorado Rivers. In 1949
I went with some friends down Glen Canyon. Then later on just boated on
the river recreationally, all over on the river system. But
was a project I undertook in 1968. It was a project I had dreamt about
doing from 1954, when William Culp Darra published the first biography
of John Wesley Powell. It was a good biography. In this book Darra mentioned
the pictures that had been taken on the second Powell expedition. I decided
right then and there that would be a wonderful project, to go back and
find the camera stations of the photographs taken by the photographers
with Powell. I kind of had in mind well, it would be something I would
do when I retired. But in 1967, late 1967, I got home from a trip, back
to Flagstaff, and read the hometown paper, the Daily Sun, and discovered
there that the U.S. Geological Survey [usgs], Smithsonian Institution
and the National Geographic Society were going to plan a centennial celebration
of Powell's first trip down the river, in 1869. I made up my mind
right then and there, now is the time to do that project. I promptly invited
myself on the organizing committee. I approached the director of the Geological
Survey and was able to get support to undertake a summers' long trip,
in 1968, starting in Green River Wyoming and ending at the Grand Wash
Cliffs, more exactly at Pearce Ferry. We tried to recapture all the camera
stations that we could, from the beginning of the second Powell expedition
through to the end. I started out with Hal Stephens who was my primary
partner in this and who was to be the photographer on our trip. We'd
jointly located sites and I took the detailed notes of each one. We organized
the trip in six sections
and the trip lasted about three months.
We did indeed start off at exactly the same point that the Powell party
started on their second expedition. Of course, we knew where it was because
we had the photographs. In fact we photographed several sites around the
town of Green River. Recaptured some of the sites that E.O. Beaman, who
was Powell's initial photographer, had taken.
Of course a number of the sites as we went down were covered over by Flaming
Gorge Reservoir, backed up behind Flaming Gorge Dam. I had seen the river
before the dam was put in. But we were able to locate fairly closely whole
series of those sites. Below Flaming Gorge Dam we then had the open river
again. Down through Red Canyon, Browns Park, down into Lodore Canyon.
And indeed, the second Powell expedition took a lot of photographs up
in that part of the trip. They became somewhat more sparing of the photography
as they went further downstream. On the second segment, then, we took
the boats out at Dinosaur National Park, put them back in again at the
head of Desolation Canyon, actually at the Ouray Indian Reservation. The
third leg of the trip was from there on down to Green River, Utah. Then
we had another group join us. We hop-scotched then, and the next segment
was down through Stillwater Canyon and Cataract Canyon. In fact Tad Nichols
and his son-in-law came up and met us by boat. By that time the reservoir
was already getting pretty high behind Glen Canyon Dam. They gave us a
tow out to the new site of Hite. But we did get some interesting Powell
shots actually somewhat up out of the river banks. Some Indian ruins that
they had photographed and some interesting inscriptions of the Powell
party, on the rocks, now under water. Then we had to just portage around
Lake Powell and put the boats back in at Lees Ferry
that work on down through Grand Canyon.
Turned out that E.O. Beaman left the Powell party midway through the 187172
trip. Powell and his crew wintered over in Kanab, Utah. Beaman had a falling
out with Powell. Powell bought out Beaman's share of the photographs
and equipment. He hired a new photographer out of Salt Lake City who actually
did go back out. They had cached one boat at the mouth of North Wash.
The party went overland and discovered the Escalante River. This is on
horseback. Thompson was in charge of that, and they went back and recovered
the boat that was cached there with a complete set of photographic gear.
They took pictures coming down Glen Canyon the following spring. The photographer
that Powell had hired really wasn't physically up to it. He was fairly
sick. In the meantime he succeeded in training John Hillers, whom Powell
had hired in Salt Lake City as an out-of-work mule-skinner, who had become
a boatman on the trip and had just picked up photography. Having been
trained a little bit along the trip, he turned out to be a superb photographer.
The rest of the photographs taken down through the Grand Canyon were taken
by Hillers instead of Beaman. We spent about a month, starting at Lees
Ferry and taking out at Pearce Ferry; recovering Hillers' camera
stations all the way down through Marble Canyon and on down through the
Grand Canyon. Actually the Powell party took out in the summer of 1872
at Kanab Creek. They had a supply coming in on horseback at Kanab that
brought supplies down to the river to re-supply. They were going to re-supply
but the river was so much higher than Powell had seen it in 1869 that
he decided the better part of valor was to abandon the river at that point.
So Hillers took a series of pictures going up Kanab Creek, which we did
follow out on foot for about eight miles up Kanab Creek. That was about
as far as the remaining pictures go. It turns out that during the winter
encampment in Kanab, Hillers had gone with Powell's cousin and scrambled
down from Toroweap Valley down to Lava Falls. So there were a series of
Hillers' pictures taken at Lava Falls. Even though the second expedition
didn't actually make it to Lava Falls on the river, we had a very
nice sequence to recover there. So that was as far downstream as we had
photographs to recover from that second expedition.
1928 ~ 1997
In 1994 a little handful of gcrg regulars got to go on an unbelievable
trip. We started out calling it the Legends Trip but then
that seemed kinda puffed-up after awhile (especially to all the other
Legends that didn't happen to be on it), so pretty soon we dropped
that for the Old-Timers Trip, which wasn't totally true
either, or at least only in a relative sense. But there actually were
a few Legends on it, and one of them was Gene Shoemaker. He was a world
famous astro-geologist who had received the country's highest scientific
honor, the National Medal of Science in 1992. He had been all over the
pages of Time Magazine recently for discoveringalong with his wife
Carolyn and one David Levythe Shoemaker-Levy Comet, which had then
smacked Jupiter in the midst of great fanfare and applause here on Earth.
And as if that alone weren't enough, here he had a river history
He only had time to go to Phantom Ranch and so we banged out a short interview
with him. We hated to see him go, because his good spirits and plain-spoken
style had added immeasurably to our own enjoyment on this river trip.
He was a young man though, a mere 62, and in pretty good shape. So even
though we weren't all that happy with the half-assed interview we'd
done on this trip, we figured, as we watched him disappear around the
bend, we'd catch up to him again sometime down the road.
How valuable is photo matching to the United States Geological Survey?
What do you get from matching these things?
We were basically the first persons, Hal Stephens and I, to go back and
do this kind of thing.
Nobody had thought of it.
Nobody had ever gone back and tried to match photographs. It soon became
a popular sport. [laughs] A lot of people got into going back and looking
at old photographs. And matching the sites to see what the changes were.
We really had two objectives in this work. One of them was simply to develop
a good descriptive album of the beautiful work that Hillers and Beaman
did. They deserve to be recognized as pioneer photographers of the west.
While Jackson and several others had gotten quite a reputation, there
had never been systematic publication of the photographs from the second
Powell expedition, which was really pioneering work. So my first objective
was really to publish these photographsget them known to the public.
Do it in a way to describe what's there and to give these pioneers
credit for what they had done. We intended the book to be out in time
for the Powell Centennial, but what happened was that I left the full
time employment with the usgs in the end of 1968 and went to Caltech.
While we had all the photographic material ready, and the maps, there
just wasn't time to bring it all together. The book was published
after Stephens retired and had the time to sit down and finish pulling
it all together. So we didn't make that one objective of getting
the work out for the Powell Centennial, which was the initial intent.
The second intent was that I hoped to learn something about the nature
of the changes in this country. I had no idea what we were going to discover
because no one had ever done it before. It's an ideal placecoming
down through the canyons of the Colorado Plateau. It's one of the
least disturbed areas. If you exclude the dams and all, the areas that
have not been affected by the damsthat's one of the least disturbed
areas left, in the conterminous United States. So you see what my idea
was; to try to understand something about the rates of geologic processes.
The rates of change on the river bank or in the side canyons. The canyon
wallswhat I found was a surprise, frankly. We found that in 85 percent
of the cases when we went back and located a scene there was hardly any
change at all, either in the background or the foreground. Small rocks
on steep slopes were still in the same place. Cobbles on the river bank
were in the same placethat was a big surprisein most cases.
It was only in the remaining 15 to 20 percent of the cases that we actually
saw the changes. What was really interesting was there were very few intermediate
cases where there were just a few changes. Either the whole foreground
scene was changed or there was hardly anything disturbed. Just a few cases
where, say, one or two rocks had been moved. That brought home to me,
that the nature of geologic processes that sculpt these canyons, and for
that matter sculpt all of the landscape, is such that very little happens
over most of the time. Most of the change takes place in very rare events.
Usually caused by storms. They will be flash floods on the main river.
They will be debris flows on the side streams. Or a section of the cliff
falls off. At any one place the change is basically catastrophic. Nothing
happens for hundreds of years or sometimes even for a thousand years.
Then there will be a catastrophe, a local catastrophe that changes the
landscape. I think we're coming to understand now, that that is the
way most geologic processes work. Geomorphic processes. That they are
dominated by the rare several hundred year flood, or thousand year flood,
not by the annual events or the decade-al events, which has been the view
that has been embedded in the consciousness of geologists
was a view that you could go sit on the bank of a stream and see what
was doing the work on an average day. And it's not true. Very little
happens on the average day. It's that one rare day in a hundred thousand
in which most of the geologic change occurs. So that was
kind of a revelation from that book.
That preceded, of course, the work that is now ongoing, the beautiful
detailed studies that are being carried out by Jack Schmidt and Ted Melis
and Bob Webb. The way they've gone back now and looked at many many
other photographs, more extensive photographs like Stanton's collection
for example. And turned these photographs into a beautiful scientific
resource for really understanding the frequency of these events in the
How are the Stanton photos? How do they compare with Hillers' or
Stanton took a very good set of photographs too. They were much more extensive
in the Grand Canyon, by an order of magnitude over what Hillers took,
cause he was trying to document the route of his proposed railroad.
The Stanton collection, I don't know the exact number, is some order
of a thousand photos. Vastly more extensive data that dates back to the
late 1800s. So it's now been a century since Stanton's time.
They actually provide more details, more scientific information than was
available from the Powell photographs. But the basic story was there in
the Powell photographs. If you take the photographs, not just from the
Grand Canyon but from the whole river system right up through the Green,
all the way back to Green River Wyoming, you have a pretty good sample
of the Colorado Plateau in those photos.
Are the Stanton photos telling us the same thing?
Somewhat to my surprise when I just looked at the frequency of changes
from the Powell pictures, my estimate was that at any one place something
catastrophic happens on order of about once every 500 or a thousand years.
Somewhat to my surprise, they're finding from the Stanton photographs,
and from more recent photographs, that in some of these side canyons the
frequency of floodingserious flooding and debris flowsis much
higher. Higher than I would've guessed. In some cases there have
been multiple debris flows, such as at Prospect Canyon, in the course
of less than 50 years. I would've had no way of knowing with the
small coverage that we had from the Powell photographs. But I am surprised.
I still think that at any given place, if you look at these really enormous
debris fans that we see, there are occasionally huge floods that I think
are on the order of every thousand years, that build a major fan. Then
you have smaller debris flows in between time, that make small modifications
to that. The truly big fans in this section of the canyon probably are
built with the frequency of about once every thousand years or so.
I should mention that there were multiple purposes in the Grand Canyon
part of our 1968 trip. We were doing a series of guide books. In fact,
the guide book for this part of the Canyon, which was written by Simmons
and Gaskill was one of those specific things. In addition, Tad Nichols
and his son-in-law were along and Tad was taking photography specifically
for a documentary on Powell, as a part of the Powell Centennial. So we
were meeting a number of objectives on the trip in addition to Lee Silver's
work with the sampling to study the crystalline precambrian rocks. One
of the little amusing parts of getting the publications going on the guide
books you might be interested in
the Powell Society really didn't
have any money except what the members themselves, which was a very small
group, might put in. So we were trying to figure out how to get the first
guide book published. The idea was to get it published and to sell enough
guide books that that would amortize the cost. Then we could publish the
next guide book and get a whole bunch of them going. So someone came up
with a bright idea. Might've been Henry Toll or Dave Gaskill, Why
don't we give a big public lecture on the trip? So I agreed
to do that, and they hired a big auditorium in Denver, the Phipps Auditorium.
I had a whole set of slides worked up. They were the old three and a quarter
by four lantern slides on glass. There were these great big projectors.
And we filled the hall. We got a tremendous take. It worked! And I had
this special set of slides that showed on one projector a picture taken
by Beaman or Hillers. On the other projector it would be the matching
photograph by Stephens. I told this story, that in most cases there was
no change. You could see the same boulders sitting there on the river
bank. Then in the small 15 percent case you could see dramatic changes.
Then we finished the lecture with Stephens' movie that he had put
together with the materials that he shot with this small waterproof wind
up motion picture camera that we carried down with us. So the lecture
was a smashing success. We published the first guide book. But you know
the funny thing is that lecture wouldn't die. I thought I had prepared
that material for a one shot deal. And I kept on giving that lecture for
years and years. It was so popular and people would see it at one place
and word would get around, next thing I'd know they would want me
to give it some place else. I kept on giving that lecture for twenty years.
Your first trip through here was in 1968, when you were doing the Powell
match up. But you started boating in the 1950s?
I started boating in 1949 just with friends, you know. After 1951, Carolyn
and I with other friends would run Cataract Canyon, or the San Juan or
up through Flaming Gorge. In fact we spent some time getting around making
sure we ran through all of the canyons before they disappeared under reservoirs.
So we, for example, went back down the San Juan and the lower part of
Glen Canyon the year just before the canyon was closed with the construction
then. Say a last good-bye to it
Working on the Colorado Plateau I knew the geology intimately, over a
broad area. That's of course what made it possible. Having seen all
the canyons and the upper part of the river system, and knowing the geology
is really what made it feasible to do that 1968 trip, and know where to
look, and get all the pictures sorted out. It turned out that the photographs
were not very well identified. The photographs from the second Powell
expedition had plates. These old classical wet plate photographs had gone
into the usgs collection and never been systematically cataloged. There
had been an album of prints made from these plates, but it was all mixed
up with other things. It was something that was done in Jack Hillers'
lab. Jack Hillers went on to become the chief photographer for the usgs
when the Powell Survey was amalgamated with the other surveys in 1879.
Hillers had those plates and they were just part of the survey collection.
I would judge that it was about twenty years after the trip that someone
sat down and tried to identifyand say oh yeah, this picture was
from here and that was from there. My hunch is that Thompson did it, but
I'm not sure. Thompson was really the guy in command of the river
trip, most of the second Powell expedition, because Powell himself was
off making trips back to Salt Lake City and working on logistics and things.
Most of the captions were reasonably close. But you couldn't tell
for sure where they were. Some cases they had the pictures on the wrong
river. So it was a task to sit down and figure out where these photographs
were taken. Those were the first order of detective work. Having done
all the previous boating on the rivers was a good head start to finding
. We didn't know how tough it would be. It turned
out we hit our schedule right on the nose. There were a few we didn't
catch. We realized we had gone past them and it was too late. Just a few
in that case. We lost a couple prints in the river when we were running
through a rapid or something. But we recovered most of the existing pictures.
Actually there is a story about that collection itself that most people
don't know. During the 1930s there was an edict that went out that
the Government had to reduce its files. So a decision was made that the
collection of negatives was going to have to be reduced in the usgs photo
lab. Believe it or not they actually removed, presumably destroyed, some
of the original plates from the Powell Expedition. The man that made that
decision was Julian Sears, who was assistant director at the time. I have
a hunch that those plates still exist somewhere. Can't imagine that
they broke them, and threw them away. [laughs] But we did have prints,
at least had the prints, even if the original negatives were gone. Some
of the pictures that we published are just from those prints. The original
plates don't exist anymore.
What was [your first Glen Canyon trip] like?
That was a total surprise. Our very first trip when we went down Glen
Canyon, there were just two other companions with me. One was a young
lady geologist, who was Doris Blackman. She is now Doris Weir, who I have
known over the years. In fact she has just retired from the usgs. Another
was a draftsman by the name of Ken Gardner. We all worked in the usgs
offices in Grand Junction where the uranium exploration program was being
carried out. We came down in Ken Gardner's home made car, made out
of various pieces and parts of other vehicles. We called it the Gardner-Mobile.
In fact there was a Gardner car. He actually had hubcaps that said Gardner
on them. [laughs] We drove very slowly down North Wash and in those days
there wasn't much of a road. Camped over night in the wash and ended
up down at Hiteat the Ferry that was run by Art Chaffin. It was
an interesting thing in itself, that old Ferry. We got down there fairly
early in the day. So we had these two dinky little river boats from Sears
Roebuck that we tied end to end. [One of those became known as the good
ship Sink-well.] And Gardner was going to go along behind in the one boat,
'cause he only had one hand. He had sawed off his hand in a sawmill
as a young man. He'd made his own hook and he could paddle that with
a kayak paddle. With his hand and his hook. Doris and I were going to
paddle up front, and that's the way we were going to go down this
river. Well, Doris and I had paddled around a little on the Gunnison River.
We had a pretty good idea how to do it. But we had never put these boats
together and paddled with Gardner. We put the boats together and said
Well, let's take a little spin out in the river, out by the
Ferry. And we dang near didn't make it back to shore, because
we were not coordinated.
Well we knew
Doris and I knew
a few hundred yards down the river
and we'd get coordinated all right. But it scared the daylights out
of Gardner, because his density was actually greater than water and he
couldn't swim a stroke. He was deathly afraid of the water. So there
we were, trying to persuade Ken that it was OK to go. And we went to bed
that night thinking Well, the river trip is over because Gardner
isn't going to go with us. We woke up the next morning and
here comes a row boat, down the river. Turned out there had been a party
that camped at the mouth of North Wash about five miles upstream that
night, unbeknownst to us. This fellow pulls in at the Ferry to talk to
Chaffin, and we go out to find out who it is. And it's Bert Loper.
Turns out he is leading a whole troop of boy scoutsabout 50 boy
scoutscoming down the river. They weren't there yet. They were
coming behind him. When Gardner found out who it was and we learned what
he was going to do, we persuaded Ken that if we got the boats packed up
and got ahead of Loper, that he would be safe. So that's what we
did. [laughs] We packed up and got out there on the river ahead of Loper
and the boy scouts. And that's how we got launched on the river.
We pretty much stayed ahead of Loper until we got down to Rainbow Bottom,
at the mouth of Aztec Creek, where you used to hike up to Rainbow Bridge.
We were hiking up then and we had a pretty good visit with Loper there.
Then we learned that his plans were to join his friends at Lees Ferry,
and continue on down the Grand at that time. Part of the story was that
Loper had gone down the Grand Canyon ten years before
made a pact with each other that if Loper lived to be 80 years old they
would do it again. And this was the time. In fact Loper would've
been 80 in the Canyon if he had made it on down. We of course pulled out
at Lees Ferry and drove home to Grand Junction. But Loper and his friends
came on down.
That was the one [Loper's last trip]?
how old do you think the Canyon is?
I have very strong prejudices about that because I've worked in the
upper end of the system, in particular the Little Colorado River Valley.
Worked on the
Bidahochee Formation. I'm confident there was a through-flowing stream
going west, or north-west, across the Kaibab Uplift in Miocene time, but
it was not connected to the lower part of the Canyon, that's clear.
The lower part of the Canyon can not be much older than about four million
years. But there was the beginning of the cutting of the river as it crosses
the Kaibab uplift, at the nose of the Kaibab Plateau, which is much older.
I think there was an integrated drainage system. There was a Colorado
River System with its tributaries that was probably here on the Plateau,
sort of in the configuration that you see now, going all the way back
to the beginning of Oligocene time about 30 million years ago. But the
river clearly didn't go out through where the lower Colorado does
now. It must've crossed, I believe, over the Basin-and-Range province
and emptied into the Pacific somewhere along the latitude of northern
California now. You know
that's still an open story. But the
upper part of the Colorado was then captured by the lower Colorado working
up from the Gulf of California, which is a very young feature geologically,
in the last four million years.
What turned you toward Astronomy?
I got into Astronomy through the back door. I was interested in the idea
of going to the moon. In fact this idea came to me rather suddenly in
1948, shortly after I joined the Geological Survey. I had been a student
at Cal Tech and was familiar with the development of rockets that had
been going on at the Jet Propulsion Laboratory
and that they were
flying these rockets as upper stages on the captured German V-2s. I just
got to thinking about that. You know, they're going to go to
the moon in my professional lifetime. They are going to send human beings
to the moon. I made up my mind right then and there that I was going
to be standing at the head of the line when the time came for scientists
to be chosen as lunar explorers. This was ten years before nasa was founded.
I just simply took those turns in the road that I thought would lead me
to being the best prepared field geologist to go study the moon. I had
an opportunity to go study Meteor Crater, Arizona. I had been working
on volcanic craters at the Hopi Buttes, which in fact have forms that
are rather similar to some of the smaller lunar craters. I thought I ought
to be working on impact craters as well, so I did seize that opportunity.
Having worked on an impact crater, the first question a geologist asks
is, Well, how often does this kind of thing happen? What is out
there? What kind of bullets are out there that hit the earth that make
craters? I immediately made it my business to find out what was
known about earth-crossing asteroids at the time. There wasn't a
lot. In fact there were about eight of them known at the time I worked
out at Meteor Crater. In fact, most of them had been lost. Only a few
of them had well determined orbits. In the meantime the lunar program
did come along. As it turned out, I didn't become an astronaut because
my adrenal cortex failed just a couple years before scientists were chosen.
I ended up chairing the National Academy's ad hoc selection committee
instead of being one of the guys standing in line. But that wasn't
the reason for getting deeply into studying the geology of the moon
started a lunar geologic mapping program, in the usgs, funded by nasa,
and we continued to study craters. It was important to study craters to
be able to interpret what we were seeing on the moon. So my first involvement
with telescopes was actually in working on lunar geology, cause
we had to go to the telescope to get higher resolution than was available
in even the very best telescopic photographs we could work from. In fact,
I had a telescope built, near Flagstaff on Anderson Mesa, where we carried
out part of that program of observations to work out the critical details
for unraveling the stratigraphy of the lunar surface. So that was sort
of my first direct involvement with telescopes. Later when I went to Cal
Tech to become the Chairman of the Division of Geological Planetary Sciences,
I hired a young woman to work with me by the name of Elenore Helin [Bruce
(from pro) Helin's mom]. I set her on the task of tracking down every
scrap of information we could find about the discovered earth-crossing
asteroids. I'd seen an opportunity to work on that problem. It turned
out there were only thirteen that had been discovered by that time, all
of them just accidentally. We finally decided that the best way to get
any further knowledge was to go search for them ourselves. So I started
a program and Helin actually carried out most of the observations with
a small Schmidt telescope on Palomar Mountain, where time was available
to do the work. It turned out to be an ideally suited telescope for the
work, so being at Cal Tech was an important step in having been able to
start that. That started in 1973 and ended in 1983. Then Carolyn and I
started an observing program on Palomar, and this year will basically
be our last year of work on that telescope. So it's work that has
been carried on for more than 20 years.
It's hard to fathom all that stuff going on out there. Just to think
trying to figure out what's going on as far as out there
as Jupiter. Did your comet really make a big bang when it hit? [Refers
to the Shoemaker-Levy Comet which collided with Jupiter in July of 1994.]
The comet did its thing at Jupiter. All these years, you know I've
kind of had a daydream
it would sure be fun to see a real impact
in my lifetime. They are rare enough that the odds of that weren't
very high. Of course I rather imagined, maybe, it'd be a small asteroid
that would hit the earth maybe deep in the outback of Australia where
nobody would get hurt, and I'd rush over and map the crater. If I'd
really thought about it, I would've realized that if I were going
to see any impact of a comet or an asteroid during my lifetime, the most
likely case would be Jupiter, because the frequency of impact on Jupiter
exceeds the frequency on any other planet. Partly because it's bigger,
it has a very large gravitational field of influence. So it focuses the
flux of comets onto it. But I hadn't really gone through that calculation.
This was really a daydream. So it was a matter of extraordinary good fortune
that we actually discovered a comet in 1993, in March. First of all it
was broken up. It had gotten so close to Jupiter, it had been pulled apart
in Jupiter's gravitational field. Then we learned, with further tracking
by many observatories around the world, that this object was in orbit
around Jupiter. And finally it became clear it was going to actually hit
Jupiter when it came back to its closest approach to Jupiter. That was
all just an incredible series of surprises. Then of course, we're
trying to figure out, Well, what's really going to happen?
Many people worked on this problem. There was a wide range of opinions.
Some people said Oh, we're not going to see anything at all.
Those comets are going to disappear without a trace. I was pretty
sure we were going to see some results that we could resolve with the
telescope. In fact with colleagues, we obtained calculations of the plume
that's produced by the hot fireball generated by the impacthow
high it would rise, how long it would take, how far it would spread out.
Those calculations were finished only about a week before the first impact.
It would've been sooner but we had trouble getting the funding to
do the work. [laughs] Finally National Science Foundation decided, well,
I'd been co-discoverer of the comet
it would be kind of a shame
if they didn't give us a little funding to work on it too. So we
finally got our calculations done late. But I was absolutely delighted
because the first nucleus that hit Jupiter produced a plume that we could
see on the edge of the planet with the Hubble Space Telescope. It was
very close to the plume that we'd calculated. At that point I knew
we were going to really see something!
I used to be really kinda proud of being a boatman and living down here
and being tapped into all this cosmic awareness that you get, just from
contemplating the canyon and the amount of time that's involved here.
You know, if you buy into the standard geologic line. But it wasn't
until I took some astronomers down that it really jerked my head up, to
think of people who are looking way, way out there. Where does boating
fit into a life as varied as yours? Where do this river and river running
The world's a tremendously interesting place. There are so many interesting
problems, but for me, I really cut my professional geological teeth on
the Colorado Plateau. It's been my geological backyard for 45 years,
and it's a geologist's paradise. There is no other way to describe
it. Rocks are exposed here in a way that you just rarely find anywhere
else in the worlda tremendous variety of things to work on and fantastic
scenery to go with it. So it's an old love that keeps tugging me
back, while I may have my head off in the stars somewhere or the planets
and comets, moons, asteroids, it's important to come back and bang
on rocks. I still consider myself a rock-knocking geologist. In fact,
I'm still doing regular field work in Australia, mapping impact craters
there. Coming back to the canyon country and especially the Grand Canyon
is just sort of a rejuvenation, gets your geological juices flowing again.
There are a whole series of problems down here that have not been solved.
I look at them as I go down, and a couple of them I've actually started
to work on. But I've got so many irons in the fire, it's hard
to finish them.
[On the '68 trip] down the upper canyons on the Green and the Colorado,
I had this arrangement worked out with a group of guys who called themselves
the Powell Society in Denver. And the mainspring in that Society was a
forensic pathologist by the name of Henry Toll. They had incorporated
themselves as a non-profit outfit to make themselves official and they
went around and did the same thing I'd been doing with friends: going
down these various canyons before they turned the water off and they started
building a dam. But they had had some experience and most of the Powell
Society guys had been down the Grand Canyon several times, and I was glad
to have them go along. Then we got here and we had several more boats.
I'd just brought two assault boats down the river from Wyoming, but
down here the Powell Society guys brought some more boats. So, we actually
ran four boats down the river, and put two people in each boat. We just
had them rigged with rowing frames. No, I'm sorry, we had five boats.
We started off and I said I'm in good hands. Here are
these old hands on the Grand Canyon. I'd never been down the Grand
We got to Badger Rapid and we all got out there on the right bank and
looked it over. Ok, let's go run it. We ran most of the
boats down and I looked back up and here was a boat flipped in Badger.
I won't tell you who it was. I thought Well, ok, these are
experienced river runners. What have I got myself into here? We
got down to Soap Creek and flipped another boat! Oh, boy this is
going to be some trip. [laughs] Actually the second was really a
kind of a fluke flip. It was just one of those things that happens to
you, catching the curl of the wave in the tail waves. Things settled down
after that. We did flip one more boat down at Crystal. By that time Crystal
was pretty mean. It was a hard one to get through. We ran all the boats
through successfully, except the first one. We had a great bunch of guys.
I had with me, in addition to the Powell Society, Leon T. Silver, who
was professor at Cal Tech, who was the real expert on the crystalline
precambrian rocksthe older precambrian rocks in the Grand Canyon.
He had been working with the samples that had been collected by a Cal
Tech/Carnegie Institution trip. In fact I think there was more than one
trip, in the late 1930s. He'd come in by helicopter and collected
additional samples, but he had never been down the river. This was the
time for him to see the river, and he really, thoroughly enjoyed it. And
he started collecting like mad. And he took big samples. Well, he was
loading most of these samples on the boat that was rowed by Henry Toll.
This was just a ten man assault boat. This boat was getting heavy and
heavier. It was just darn near getting unmanageable.
Toll was undoubtedly the best boatman. He was good. Well, we are camped
at the mouth of Tapeats Creek and as we're camped there we see a
trip coming in. If I remember right, I think it was Sanderson. And we
discover it's a Barry Goldwater party, on the boat. It was not Barry
Goldwater Senior, it was Barry Goldwater Junior in the party. They pulled
in on river left about a mile downstream. Silver gets to thinking about
this. We've got a good boat there. I think Toll knew the boatmen
running the boat. Maybe they can get those guys to carry out these
rocks! So early the next morning we all stood on the bank and Toll
and Silver took off to go on down the river, row across and go talk to
the Barry Goldwater party. And it turned out that Toll pulled just one
of his very rare boo-boos. He went over a little bit of a drop over a
rock. Silver was sitting on the back of the boat and just tumbled right
out. Course it wasn't any heavy water or anything and he scrambles
right back on. They row over there and Silver strides out of the boat,
of course, dripping wet. Walks up to Barry Goldwater, pulls out his card,
hands it to Goldwater and introduces himself. [laughs] Goldwater says
Well, I like to do business with a man who bathes before breakfast.
Actually they did talk them into hauling out most of those samples for
Silver. Took them on downstream for us.
did you worry on that trip? How did it feel to get to the
bottom? Did you worry about Lava [Falls] and all that stuff?
Nah, I didn't worry too much about the rapids. 'Course I hadn't
seen all these rapids before.
Were you running a boat?
Sure, running my own boat. In fact I had George Anderman with me. He and
I jointly owned this boat for years, and boated together. And he hiked
down the Kaibab trail and joined us at Phantom Ranch. Yeah, we looked
over Lava, it looked pretty scary, not having run it before. In fact a
couple of guys lined their boats down. Elected not to run. And I was glad
they did. About that time Bruce Julian who had actually flipped one of
the boats up at Soap Creek, knew a good line through Lava. And he ran
it perfectly. We watched him go and I thought I could hit that line too.
But it was very hard to see that exact spot upstream as you know
know exactly where to go and it drops off so fast. I missed it by about
four or five feet. It dropped right into a hole. Got trapped in this holeboat
just stopped. I lost Anderman instantly. He hung on with all his might
onto the rowing frame, but just peeled right off into the rapid. There
I was, and the boat was just slamming around and all my bags that I had
tied down carefully were starting to come loose. The oars were flailing
around at that point. I thought I better get out of this boat before I
get pinned in it. I just worried that if it flipped over I might get stuck
in the boat. So I got out. And just about that time the boat popped out
of the hole. Boat never did flip over. It went over the big wave down
at the bottom. Stayed upright all the way and I went through in my life
preserver. Which is a non-recommended way to run Lava. I've never
yet flipped a boat on the river. But I have had a few episodes.