Traveling to the sites of modern astronomical observatories, where the air is thin and the earth touches the sky.
Each time is the usual litany of questions: “What is your business in the US,” “How long are you staying in the country,” “Can you really see the stars from Cambridge?” I always get this last question when the immigration official looks at my Visa and realizes that I am an astronomer based in a populous city in New England: how can I see the stars from a place where most of the time the sky is the same color of the orange sodium city lights? In fact, can’t. Astronomers need dark skies, thin air and low humidity. Cambridge is certainly none of the above, and the only telescope we actually have on the roof of the Center for Astrophysics mis a small amateur scope used for the monthly “Observatory Nights” for the public. Our real telescopes, the large ones, are on the top of remote mountains, in the middle of deserts or in the caldera of inactive volcanoes in the Hawaii and Canary islands. In the last few years technology has progressedto a point in which many observations can be performed remotely. I can operate the 48- inch reflector at the Fred Lawrence Whipple
Observatory in southern Arizona from the comfort of my office in Massachusetts. Thanks to robotics, and the Internet 2, I can do my job as efficiently as if I were in the control room annexed to the dome. This is the way we control telescopes that are in the only place we cannot possibly reach: space, like the Hubble telescope orbiting the Earth, or the Spitzer telescope trailing our planet more than 15 million kilometers away. 
But remote observingis not the same as being there. Sometimes you need to be reminded that the objects you are observing are real, as real as the cold air of the night burning the skin of your face while you are outside the telescope dome checking the weather.
It is easy to forget that the images appearing on your screen are not the products of a computer simulation, but are formed by a handful of photons that have traveled through the depths of space and time to tell the story of worlds we can barely imagine. And there is no better reality check than traveling to the fantastic places where the great observatories are built, and lose yourself admiring the sun rising on the Andes at the end of a productive night, or drive along the panamericana road amid endless piles of aji peppers left to dry under the sun of the desert. The first time I went alone to an observing trip I was still a graduate student freshly arrived to the US from Italy.
I arrived in Tucson, Arizona, via Dallas, after a long flight over the dry landscapes of the US southwest. At 30,000 ft the desert landscape
loses its human scale and becomes an abstract pattern of unpaved roads crisscrossing never ending plains dotted by cacti and bushes. From that height, the erosion of seasonal
rivers looks like the bite of a giant dragon, flown from the misty mountains far away where the horizon meets the sky. The observatory is near Amado, almost at the border with Mexico, in a mountain range rising from the desert, home of saguaros and well tended golf courts. Arizona is not only a heaven to astronomers, but also the last destination of a growing population of retirees in search of warm weather and the cheap medications provided by the Mexican pharmacies on the other side of the border. “Hey, You look like
an astronomer!” was the comment of Scott, the owner of a local limousine company waiting for me at the baggage claim carousel of the Tucson airport. He either has a sixth sense for spotting astronomers, or he just guessed right that only an astronomer
can travel to sun scorched southern Arizona wearing a GoreTex parka when the temperature is in the hundreds. Scott drives an old Chevrolet Caprice, and wears musketeer’s hat with an ostrich feather on top. He drove me through the desert, telling stories about the local indian tribe that exchanged ancestral land rights for a gambling license, and the hotel on the left, built inside the abandoned silo of a minuteman ICBM. Only in America, baby. He left me at the end of the Elephant Head road, at the observatory base camp. From there to the telescopes on the summit there is another hour of four-wheel drive, on a steep unpaved road passing through places with names that you would expect in a Clint Eastwood movie: “Devil’s Throne”, “Agua Caliente Trail”, the “Vault Mine” trailhead.
As I drive up the mountain, the sun is setting, and my parka suddenly becomes a very good idea to fend off the cold night of the desert. The observatory is home of several telescopes, the largest of which is the refurbished Multiple Mirror Telescope. In its previous incarnation, the telescope was made by six individual smaller mirrors on a common mount. As technology advanced, a new telescope was built, with a single mirror 6.5 meters in diameter, one among the largest in the world. The new telescope barely fits in the
old dome, like a model boat in the bottle. On the mountain ridge below the summit, there are smaller telescopes and one interferometer, that combines the light from three small flat mirrors mounted on rails to achieve very high visual acuity thanks to its “stereoscopic”
vision. My destination in that first trip was the small 48-inch telescope, the one that is now mostly controlled remotely from Cambridge. As it often happens, I didn’t observe much that time. I spent most of my three nights feeding the 4AM mouse that lives in the
control room, and checking the clouds that were hiding the stars from my sight. That’s not too unusual, and it is part of this job being caught by a sudden snowstorm in such unlikely
places like the desert of Arizona, or an observatory in Hawaii. Snow in Hawaii, yes, I got that too. But theb gamble is worth the bet, and even a few hours of good weather are enough to provide data that will take months to analyze and understand. Astronomy is an experimental science, and lives off these rare moments in which nature allows us to use the most expensive cameras ever built, attached to even more expensive optics, to investigate the secrets of how the universe, our world, and ourselves came
to be. You cannot observe the stars from Cambridge, as I often have to explain to the incredulous US immigration officials, so an important part of my job involves traveling. It can be stressing some times, but it gives me the chance of visiting many places I would have never seen otherwise. Many of the photographs on my photoblog are memories of
these travels, and tell the stories of lonely mountains rising from the dusts of a desert, and the giant telescopes that we have built on their summit.
Massimo Marengo is a professional astronomer based at the HarvardSmithsonian Center for Astrophysics in Cambridge, Massachusetts (USA). As such, he spends a lot of his time processing images taken with the most expensive cameras attached to the largest optics in the world, capturing a handful of photons that have traveled for million of years just
to end up on the screen of his computer. To resist the capital sin of applying artistic license to these scientific images, he has taken up photography to capture the more
mundane subjects encountered during his numerous travels: a landscape in a remote part of the world, the people and the stories inhabiting it. His website sports many photos taken in these trips.
