The Mauna Kea observatories on the Big Island of Hawaii.
Many of us “do astronomy”. Whether you just stand in your backyard this summer and go looking for planets, or you venture out to a dark sky destination to see a comet or catch some shooting stars, the terms “astronomer” and “stargazer” often go hand-in-hand.
The pandemic has gotten a lot of us into our backyards looking up. This rare planetary event has also given some a new perspective on our global community.
The night sky connects all humans wherever they are, but how many of us ever discover something new about what’s out there? Or even have an original thought about the enormity above us each night?
In “The Last Stargazers: The Enduring Story of Astronomy's Vanishing Explorers,” University of Washington astronomy professor Emily Levesque shares the tales of modern-day stargazers, the small band of 50,000 or so professional astronomers around the world that get to use humanity’s greatest telescopes on the high altitude peaks such as Mauna Kea in Hawaii, Cerro Paranal in Chile and Roque de los Muchachos in the Canary Islands.
It sounds impossibly romantic. Is it?
“If somebody wanted to come watch an astronomer work at night I think they’d be deeply disappointed,” said Levesque. “We’re not out gazing at the stars and we’re not even sitting out at the telescope—we’re in a lit room in a different part of the telescope building.”
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This is a world of computer screens, laptops and data. In fact, many astronomers work 9 ‘till 5 with data downloaded from remote telescopes.
That’s right; astronomers don’t look through telescopes.
"The Last Stargazers" is a new book by astronomer Emily Levesque.
What do astronomers do?
The title of Levesque’s book reflects the engaging text’s many stories about discoveries made at mountaintop observatories, but in modern terms, it’s a little ironic because professional astronomers don’t do all that much observing with their own eyes.
“People imagine an astronomer to be somebody hunkered down at a telescope, but they would be surprised at the adventures we have, and the sheer variety of things that we do for our job,” said Levesque. “But we don't look through eyepieces anymore. In terms of the technology involved—from cameras to advanced detectors—the way we do astronomy is so surprising to some people.”
However, don’t think that astronomers are stony-faced when they’re sat in front of a computer screen displaying something spectacular. “Our responses to seeing something captured by a powerful telescope are the same as the responses of amateurs looking at Saturn for the first time,” said Levesque, who’s incredibly enthusiast about astronomy. “We know all the science behind what we’re looking at, but we react in the same way as anyone enjoying looking at the night sky.”
On Palomar Mountain in California lies the Hale Telescope, that has been in use for 60 years. Photo ... [+]
Coping with cloud
Anyone who’s ever made a plan to look at the night sky has a nemesis; cloud.
That’s why the planet’s big telescopes are on mountaintops above the clouds. That’s the theory. The reality is that weather happens, and so does engineering. On the big telescopes that means only about 300 observing nights per year. So what happens if you get valuable “telescope time,” get yourself up the mountain for three nights, and the clouds come in?
Not much. “It’s all or nothing—you can get a string of good weather and a working telescope, or cloud and a broken instrument,” said Levesque. If it’s the latter, tough luck.
“You just come home and you have to apply again, and you don’t get a special little star on your proposal saying she got clouded out—you have to go back and take your chances again, just like anyone else,” said Levesque.
How astronomers get time on a telescope
Since telescope time is scheduled six months in advance at most observatories—and typically astronomers wait for a year to be assigned a slot—a single cloud or one windy night can make a huge difference to astronomical research plans. “The stakes are high—you really hope for good weather, you really hope nothing goes wrong, and you really hope you don't make any mistakes, because the time is so precious,” said Levesque.
Depending on what object they need to observe, astronomers can request a specific day or even hour (perhaps for an asteroid occultation), a season (say, anytime between November and May for observing Betelgeuse), and whether they require complete darkness or are happy with a full moon-lit night.
Sometimes astronomer will request to observe an object at a specific time to coincide with precisely when Hubble will be looking at it, so that data can be compared.
The flying observatory "SOFIA" (Stratospheric Observatory for Infrared Astronomy), a Boeing 747SP of ... [+]
NASA’s ‘flying telescope’
So astronomers almost never look though telescopes, but they always hang out on mountain tops, right?
Well, no, not always. The Mauna Kea Observatories (MKO) in Hawaiʻi are at 13,803 ft./4,207 meters above sea level, but that’s not always enough.
Some telescopes fly, so astronomers have to sometimes become “stratonauts.”
Cue Levesque’s adventures in NASA’s “flying observatory,” the Stratospheric Observatory for Infrared Astronomy (SOFIA).
Having written a couple of times recently about studies of Betelgeuse and Pluto from the specially-equipped Boeing 747SP aircraft (modified to carry a 2.7-meter/106-inch reflecting telescope), this part of the book particularly engaged me. Levesque recounts her evening with the “stratonauts” who operate SOFIA with incredible enthusiasm (a theme throughout the book).
As is the way with astronomers, she also got to see something truly exquisite.
“I was flying on that telescope as an astronomer and we were down in the southern hemisphere,” said Levesque. “I saw the southern aurora from the cockpit of the plane flying—the first time I've ever seen the aurora.”
“Never in my wildest dreams would I have imagined I would be in that place.”
However, astronomical opportunities for such incredible experiences could be on the wane.
The future of professional astronomy
Professional astronomy is no longer about looking through telescopes or hanging about in freezing temperatures. Levesque has had many experiences of how astronomy is done now—mentioning the smell of engine grease and coffee as two dominant themes—but the discipline’s next chapter seems far less exciting.
In the future will all telescopes be controlled remotely? Will astronomy be an office-based vocation?
“We’ve certainly seen a drift toward telescopes being operated remotely,” said Levesque. “One of the telescopes that I spend a lot of time using now is the Apache Point Observatory 3.5 meter telescope, which I can operate from my laptop on my couch.”
Remote control astronomy
Many are now operated using queue-based scheduling; an astronomer send instructions to the telescope ahead of time, it makes observations when the conditions are right, and the data arrives in the astronomer’s inbox.
“We will see many more telescopes run that way,” said Levesque. However, there is still a telescope operator at the telescope itself, and there are still engineers and staff on site taking care of the telescope. It’s just that the astronomy is increasingly being done remotely.
“I don’t think we’ll ever truly remove the idea of people at telescopes, except in the case of robotic telescopes, which are amazing at some things, but can’t do some things,” said Levesque. “The variety of questions we’re trying to answer with telescopes means that we’re probably always going to demand human participation at some level.”
Sunset at the Mauna Kea Observatories on the Big Island of Hawaii.
The last stargazers?
So are astronomers still stargazers?
Levesque tells a story about what astronomers do before an observing session at most mountaintop observatories. “When we watch the sunset before an observing session we pretend we’re checking to see how clear the sky is looking,” said Levesque.
“It’s a wonderful chance to enjoy the planet, enjoy the observatory, get a moment of silence and see our nearest star doing something beautiful from the edge of the world.”
Wishing you clear skies and wide eyes.
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