
In honor of the 50th anniversary of the Moon landing, we celebrate Arizona’s pivotal role in space exploration, from the Apollo missions to shoebox-size satellites to rendezvous with asteroids.
On a bright September afternoon in 1962 – in front of a large crowd in Houston, fittingly – President John F. Kennedy first announced his goal to send a man to the Moon.
Ultimately known as the “We choose to go to the Moon” speech, it ignited the American imagination like rocket fuel. But lunar science wasn’t the thing that so fired everyone up. To most people, the Moon was a bleak, bone-colored finish line in the race to beat Russia at the technology game.
Thanks to a few scientists who successfully wooed the astronauts, that perspective changed – and the Moon turned out to be far more fascinating than earthlings suspected.
Moonwalkers from Apollo missions 11 to 17 brought back lunar rocks, moon dust and core samples that told scientists tales about the origin of the solar system. Some of these otherworldly treasures were never exposed to Earth’s atmosphere but have remained sealed at NASA, awaiting the advanced technology that could unlock their secrets. This year, in honor of the 50th anniversary of the first Moon landing, that lunar cache will finally be unveiled and studied by scientists, including some at the University of Arizona. The newly opened nuggets could reveal clues about the Moon’s violent past, mysterious interior and ability to store water.
The story of how the Moon became a stage for scientific exploration began – as so many space stories do – in Arizona.
The Moon Man
Known as the father of astrogeology and a patriarch of planetary science, Gene Shoemaker was a legend in his time. He had an infectious enthusiasm, a hearty laugh that echoed down hallways, and an obsession with craters and the catastrophes that caused them. In 1960, he co-discovered the telltale minerals that proved Arizona’s Meteor Crater was blasted by a meteor, not a volcano, as many people had thought. After inventing the branch of astrogeology within the U.S. Geological Survey (USGS) in California, Shoemaker moved the program to Flagstaff in 1963. He wanted to be close to Lowell Observatory and the area’s lunar landscapes – perfect for training moonwalkers.
The same year, Shoemaker was diagnosed with a nonlethal adrenal gland disease that ended his personal dream of going to the Moon. Still, more than any other person, Shoemaker convinced the government that the Apollo astronauts could advance scientific discovery. He did this mainly by winning over the astronauts. Shoemaker knew he needed to seduce these daredevil pilots into the world of geology. So, starting in 1963, he invited them to Northern Arizona.
All 24 of the Apollo astronauts who walked on or orbited the Moon trained in Arizona. Donning Stetsons and carrying geological charts, the space cowboys hiked around Meteor Crater, where Shoemaker and others taught them to recognize the meteoric remnants they would see on the Moon. They trekked the Grand Canyon, where Neil Armstrong learned to wield a rock hammer and pinpoint his location on aerial photographs – necessary skills for moon-rock-collecting expeditions. Surrounded by canyon walls striped gold and red like Jupiter’s clouds, the astronauts were inspired. As Buzz Aldrin wrote, “Geology opened my eyes to the immensity of time when… I found myself standing at the bottom of the Grand Canyon paying rapt attention as the instructor talked about things that took place eons before man existed on this earth.”
Photos courtesy Center of Astrogeology, U.S. Geological Survey
The volcanic cinder cone fields near Flagstaff were naturally a satisfactory stand-in for the Moon. But USGS scientists enhanced the resemblance by dynamiting hundreds of craters into the ground to precisely replicate the Sea of Tranquility, where the Apollo 11 Eagle lunar module would famously land. Shoemaker’s teams of geologists and astronauts lurched over the stone-streusel cinder rubble in spacesuits, testing the equipment. They rehearsed collecting geological samples. They learned topographical skills so they wouldn’t get lost on the lunar highlands. And they test-drove replica rovers they would cruise across the Moon’s powdery, pockmarked expanse. As a salute to their Flagstaff training, Apollo 16 astronauts Charlie Duke and John Young – who flew to the Moon in 1972 – named a lunar crater near their landing spot “Flag Crater.”
Years later, after co-discovering the Shoemaker-Levy comet that collided with Jupiter, Shoemaker was killed in a car crash while studying craters in Australia. One of his former students, University of Arizona planetary scientist Carolyn Porco, heard the news and had an inspiration. She arranged to grant Shoemaker’s dearest wish. Two years later, after the NASA spacecraft Lunar Prospector finished its mission, it deliberately crashed into the Moon, carrying Shoemaker’s ashes, a photo of Meteor Crater and a passage from Romeo and Juliet:
“And, when he shall die,
Take him and cut him out in little stars,
And he will make the face of heaven so fine
That all the world will be in love with night,
And pay no worship to the garish sun.”
Arizona Al Astra
Arizona may be known for its sunshine, but the state is in love with night. Our connection to stars, planets, moons and other heavenly bodies runs deep. We have the most telescopes and International Dark Sky Communities in the country. We have the Vatican’s own telescope at Mount Graham in Southeastern Arizona. In April, U of A astronomers helped coordinate two of the eight telescopes – one on Mount Graham and one in Antarctica – that together captured the first image of a black hole. At Lowell Observatory, astronomer Clyde Tombaugh discovered Pluto, and Vesto Slipher detected the first evidence of the expanding universe.
Arizona State University has been involved in several Mars missions, including the Spirit, Opportunity and Curiosity rovers, and the Mars 2020 rover launching next year. Last year, ASU cosmologist Judd Bowman and others observed long-elusive signals from the first stars born after the Big Bang – signals that may be evidence of dark matter mingling with regular matter. Some experts say the discovery could be worth two Nobel prizes.
The University of Arizona’s Lunar and Planetary Laboratory was founded in 1960 by Gerard Kuiper, whose name you may recognize from the Kuiper belt, the massive ring of icy objects orbiting the outer solar system. (In 2015, NASA’s New Horizons spacecraft, carrying Tombaugh’s ashes, passed by Pluto; this year, it photographed the most distant object ever explored –
Ultima Thule in the Kuiper belt.) Since 1964, the U of A has been involved in every NASA planetary mission, including the Voyager “grand tour of the solar system,” for which Porco was a member of the imaging team. And the U of A-led Phoenix Mars mission was the first to confirm the existence of water ice on the Red Planet.
Now both universities are leading missions that are propelling space exploration to new realms. Find a few of the highlights on the following pages.
OSIRIS-REx
As you read this, OSIRIS-REx is about 70 million miles away, orbiting Bennu, an Empire State Building-size asteroid that spews mysterious particle plumes. The U of A-led mission, using a spectrometer built at ASU, rendezvoused with Bennu in December and has already reported startling findings.
“The discovery of plumes is one of the biggest surprises of my scientific career,” principal investigator Dante Lauretta announced at a news conference in March. “And the rugged terrain went against all of our predictions. Bennu is already surprising us, and our exciting journey there is just getting started.”

Bennu – part of a family of asteroids known as NEOs (near Earth objects) – may harbor material from the dawn of the solar system, or even earlier. It’s essentially a cosmic time capsule that could tell us about the history of the sun and planets. The carbon-based asteroid is similar to those that may have crash-delivered the original organic matter and water to Earth, so it may conceal clues to the origin of life. It also has a slight (1 in 2,700) chance of colliding with Earth sometime in the 22nd century.

Currently, scientists are searching for a landing spot on the unexpectedly boulder-strewn surface, so OSIRIS-REx can scoop up a rock sample. If it successfully returns to Earth in 2023, at its designated landing spot in Utah, it will be the first U.S. spacecraft to bring chunks of an asteroid back home.
Phoenix CubeSat
A spacecraft the size of a bread loaf will soon be measuring the oven-like heat above Phoenix and other cities. Launching in November, the CubeSat – an academic term for a type of mini satellite – will fly for two years at an altitude of about 250 miles. It will capture thermal infrared images to determine how different city designs affect the intensity of the urban heat island effect – a phenomenon in which steel and concrete jungles burn hotter than their rural surroundings.


Unlike large, sun-synchronous government satellites such as Landsat, which observe the same place on the planet at the same time of day, the Phoenix CubeSat will take measurements at various times of day. That’s important because the urban heat island effect fluctuates dramatically between day and night.
The Phoenix CubeSat is an ASU student-led project funded by NASA and is part of a growing movement toward smaller, more affordable spacecraft. “We view the Phoenix project as contributing to the trend of helping local governments and communities have direct access to space to address their own local needs,” says principal investigator Judd Bowman. “We hope it is piloting a new way in which ASU can help the local community.”
“Our hope,” project manager Sarah Rogers says, “is that our science team will one day work with urban planners to help make our cities more sustainable.”

LunaH-Map
ASU’s LunaH-Map mission is a space-age version of The Little Engine That Could. In 2020, this CubeSat the size of two shoeboxes with solar panel wings will sail to the Moon, propelled by an ion thruster that “produces the same amount of force as dropping a human hair on a table,” says principal investigator Craig Hardgrove. Performing its first flyby of the lunar surface four days after launch, the craft will then execute a long, circuitous slingshot around the Moon and Earth to achieve the optimal angle for orbital capture. LunaH-Map will then fly about 3 miles above the lunar South Pole for two months, using a neutron detector to map ice water in permanently shadowed regions. “We want to understand how did this water get delivered to the Moon, and what does this tell us about the history of the delivery of water when the Moon and Earth were forming,” Hardgrove says. Ice cartography is also important for future crewed and rover missions, since water can be used to make rocket fuel by splitting the H and O in H2O. That means the Moon could become a “gas station” for future space-age engines that could.
LROC and ShadowCam
Far from being inactive, the Moon is twerking the night away. We know this thanks to the Lunar Reconnaissance Orbiter Camera (LROC), an ASU-led camera that has been producing high-res images of the lunar surface for the past decade. Recently, scientists combined LROC photographs of “wrinkle ridges,” “stretch marks” and landslides with data from seismometers placed on the Moon by Apollo astronauts. They concluded that the cooling moon is shrinking like a raisin in the sun, and it’s quaking as it contracts.

LROC’s images have transformed our vision of the Moon. Scientists previously thought lunar volcanism stopped about 1.5 billion years ago. LROC revealed evidence of volcanic activity 10 to 50 million years ago. Now, LROC principal investigator Mark Robinson of ASU, is leading another moon-imaging effort: ShadowCam. Slated to launch in 2020, ShadowCam will wield a camera so sensitive it can essentially see in the dark. It will sleuth for ice in the Moon’s permanently shadowed regions (PSRs), located in the bottoms of craters. Robinson says if there are significant amounts of ice, humans could use solar power to melt it into water, breathe the oxygen out of it and turn it into fuel. “So if we’re going to end up living and working on the Moon, it would be an incredibly valuable resource.”
Psyche
A “journey to the center of the Earth” could happen only in fiction. Our planet’s core lies at crushing pressures 1,800 miles below ground and broils at 8,000 to 10,000 degrees Fahrenheit. So if we want to learn about the core of the Earth and other terrestrial worlds, we have to find a surrogate. Scientists may have found one in Psyche, an asteroid hurtling around the sun between Mars and Jupiter.

Of the millions of asteroids in our solar system, we know of only nine we suspect are made of metal, just as our core is. Psyche is the largest of those, with a diameter roughly equivalent to the distance between Phoenix and Flagstaff. Scientists think it’s a planetary core that had its mantle bashed off in multiple collisions.
The ASU-led Psyche mission, launching in 2022, will mark the first time we venture to a metal world. “This is prime exploration of a kind of object that humankind has never seen before,” says principal investigator Lindy Elkins-Tanton, director of ASU’s School of Earth and Space Exploration. “We want to investigate how it is that rocky planets melt and allow their metal to sink in the interior and form a core – a process we’ll never see, and the results of which we can’t reach directly unless we go to Psyche. It’s the only chance.”

The first objective is to determine whether Psyche is a planetary core or if it’s some other bizarre oddball. Then scientists will try to suss out how it formed, what it looks like, its chemical composition, and whether it ever had volcanoes.
In the meantime, this highly collaborative NASA mission, which has involved more than 200 undergraduates in its first two years, has launched free online classes so the public can learn about robotic space missions. “Space exploration is an incredibly effective vehicle for people to get excited about learning,” Elkins-Tanton says. “To me, the real reason we do space exploration is to inspire everyone on Earth to be bolder in our own lives.”
AZ Space Hardware
Photos courtesy Nasa and Nasa/Goddard Space Flight Center
Spirit
Launched in 2003, this water-sniffing rock hound prowled the Martian surface for five years before getting fatally mired in a sand bed. It was partially developed at Arizona State University.
Opportunity
Launched a month later than Spirit, it proved more durable than its twin, reporting on Martian climate and geology for 14 years before going dark in February 2019. Both rovers had drill casings made with salvaged metal from the World Trade Center.
Lunar Reconnaissance Orbiter Camera (LROC)
ASU professor Mark Robinson is principal investigator of this Moon-mapping NASA orbiter, which has detailed 98 percent of the lunar surface since launching in 2009.
Shoemaker-Levy Comet
Arizona astronomers Carolyn and Eugene Shoemaker, working with research partner David Levy, discovered the famed comet on March 24, 1993 – 15 months before it crashed into Jupiter, releasing the energy equivalent of the world’s nuclear arsenal 600 times over.
Curiosity
Still operational, the crater-snooping, car-size rover has long outlived its 2-year mission since landing on Mars in 2012, continuing to run habitability studies as a precursor to a manned mission.
2020
Pegged for an August 202O launch, this roving astrobiologist will cache soil samples for a possible Mars sample return mission. It will also sport a helicopter drone.
Lunar Events
Through the end of the year, Lowell Observatory, the Flagstaff Festival of Science and other Flagstaff entities will continue to celebrate the moon landing with lectures, exhibits and even lunar-themed food and drinks at local eateries. flagstaffarizona.org/lunarlegacy
July 20
Lowell Observatory will celebrate the day astronauts first walked on the moon with a talk from USGS geologists who trained Apollo astronauts and current astronauts; as well as Gene Shoemaker’s widow, Carolyn Shoemaker, who has discovered more comets than any living astronomer. The event will also showcase video of the moon landing and a band playing moon-themed music.
July 20
MonOrchid Gallery in Phoenix will host a panel discussion and showcase stunning photographs from the Lunar Reconnaissance Orbiter Camera through the end of July.
September 20
Kicking off the Flagstaff Festival of Science is keynote speaker Charlie Duke, one of four remaining moonwalkers, who will speak about his training in Arizona and his exploration of the moon. The free, weeklong festival is also hosting lunar lectures throughout the year.