It is an exciting time for astronomers and cosmologists. Since the James Webb Space Telescope (JWST), astronomers have been treated to the most vivid and detailed images of the Universe ever taken. Webb‘s powerful infrared imagers, spectrometers, and coronographs will allow for even more in the near future, including everything from surveys of the early Universe to direct imaging studies of exoplanets. Moreover, several next-generation telescopes will become operational in the coming years with 30-meter (~98.5 feet) primary mirrors, adaptive optics, spectrometers, and coronographs.
Even with these impressive instruments, astronomers and cosmologists look forward to an era when even more sophisticated and powerful telescopes are available. For example, Zachary Cordero of the Massachusetts Institute of Technology (MIT) recently proposed a telescope with a 100-meter (328-foot) primary mirror that would be autonomously constructed in space and bent into shape by electrostatic actuators. His proposal was one of several concepts selected this year by the NASA Innovative Advanced Concepts (NIAC) program for Phase I development.
After a quarter-century of development, NASA’s James Webb Space Telescope is a smashing success. But senior project scientist John Mather, a Nobel-winning physicist who’s played a key role in the $10 billion project since the beginning, still sees some room for improvement.
The search for technosignatures has always taken a back seat in the broad search for extraterrestrial life forms. Biosignatures, such as methane in an exoplanet’s atmosphere, have long been front and center. But while we are searching for signs of biology, signs of technology might be hiding in plain sight. According to a new report from the members of the TechnoClimes conference, humanity could potentially find signs of technology by simply using data that will already be collected for other purposes. To prove their point, they came up with a list of possible technosignatures and cross-referenced them with a list of observatories that could potentially find them. The result is a framework of how to best search for technosignatures and a plethora of references for those seeking them out.
It’s that time again. Once every ten years, the American astronomy community joins forces through the auspices of the National Academies to produce one of the most important and influential reports in their discipline – the decadal survey. This report has been the impetus for some of the great observational instruments of our time, including Spitzer, the Large Millimeter Array, and Chandra. Upcoming heavy-hitting observatories, such as Nancy Grace Roman and Vera C. Rubin, also spawned from suggestions made in the Decadal Survey. In short, if you want to get a grandiose space telescope funded, your best bet is to have it supported by the National Academies in the form of the Decadal Survey. Now a new one is out – so what does it back for the upcoming decade and beyond?
You could say that the study of extrasolar planets is in a phase of transition of late. To date, 4,525 exoplanets have been confirmed in 3,357 systems, with another 7,761 candidates awaiting confirmation. As a result, exoplanet studies have been moving away from the discovery process and towards characterization, where follow-up observations of exoplanets are conducted to learn more about their atmospheres and environments.
In the process, exoplanet researchers hope to see if any of these planets possess the necessary ingredients for life as we know it. Recently, a pair of researchers from Northern Arizona University, with support from the NASA Astrobiology Institute’s Virtual Planetary Laboratory (VPL), developed a technique for finding oceans on exoplanets. The ability to find water on other planets, a key ingredient in life on Earth, will go a long way towards finding extraterrestrial life.
Is there an alien civilization next door? It’s…possible(ish). In late 2020, we discovered a signal from the direction of Proxima Centauri (not necessarily from Proxima Centauri), our closest neighbour star. Named BLC- 1 by project Break Through Listen, the signal is still being analyzed to ensure it isn’t simply an echo of our own civilization – typically what they turn out to be. But why not just directly look at planets in Proxima Centauri and see if a civilization is there?
From space, the most obvious sign somebody lives on Earth is the glow from the nightside of our planet. Our cities emit light that’s shed into the Cosmos. Problem is that our current generation of telescopes are not powerful enough to see lights on distant worlds. But several researchers are testing the capabilities of the next generation of telescopes already on the drawing board. The finding? Yes! if advanced enough…or glowy enough…we would be able to see if another civilization has the lights on at Proxima Centauri.
Upcoming telescopes will give us more power to search for biosignatures on all the exoplanets we’ve found. Much of the biosignature conversation is centred on biogenic chemistry, such as atmospheric gases produced by simple, single-celled creatures. But what if we want to search for technological civilizations that might be out there? Could we find them by searching for their air pollution?
If a distant civilization was giving our planet a cursory glance in its own survey of alien worlds and technosignatures, they couldn’t help but notice our air pollution.
It’s possible that you’ve seen the Andromeda galaxy (M31) without even realizing it. The massive spiral galaxy appears as a grey, spindle-shaped blob in the night sky, visible with the naked eye in the right conditions. It’s the nearest major galaxy to ours, and astronomers have studied it a lot.
Now astronomers have used the Hubble Space Telescope to map out Andromeda’s enormous halo of hot gas.
One night 400 years ago, Galileo pointed his 2 inch telescope at Jupiter and spotted 3 of its moons. On subsequent nights, he spotted another, and saw one of the moons disappear behind Jupiter. With those simple observations, he propelled human understanding onto a path it still travels.
Galileo’s observations set off a revolution in astronomy. Prior to his observations of Jupiter’s moons, the prevailing belief was that the entire Universe rotated around the Earth, which lay at the center of everything. That’s a delightfully childish viewpoint, in retrospect, but it was dogma at the time.
Until Galileo’s telescope, this Earth-centric viewpoint, called Aristotelian cosmology, made sense. To all appearances, we were at the center of the action. Which just goes to show you how wrong we can be.
But once it became clear that Jupiter had other bodies orbiting it, our cherished position at the center of the Universe was doomed.
Galileo’s observations were an enormous challenge to our understanding of ourselves at the time, and to the authorities at the time. He was forced to recant what he had seen, and he was put under house arrest. But he never really backed down from the observations he made with his 2 inch telescope. How could he?
Now, of course, there isn’t so much hostility towards people with telescopes. As time went on, larger and more powerful telescopes were built, and we’ve gotten used to our understanding going through tumultuous changes. We expect it, even anticipate it.
In our current times, Super Telescopes rule the day, and their sizes are measured in meters, not inches. And when new observations challenge our understanding of things, we cluster around out of curiosity, and try to work our way through it. We don’t condemn the results and order scientists to keep quiet.
The first of the Super Telescopes, as far as most of us are concerned, is the Hubble Space Telescope. From its perch in Low Earth Orbit (LEO), the Hubble has changed our understanding of the Universe on numerous fronts. With its cameras, and the steady stream of mesmerizing images those cameras deliver, a whole generation of people have been exposed to the beauty and mystery of the cosmos.
Hubble has gazed at everything, from our close companion the Moon, all the way to galaxies billions of light years away. It’s spotted a comet breaking apart and crashing into Jupiter, dust storms on Mars, and regions of energetic star-birth in other galaxies. But Hubble’s time may be coming to an end soon, and other Super Telescopes are on the way.
Nowadays, Super Telescopes are expensive megaprojects, often involving several nations. They’re built to pursue specific lines of inquiry, such as:
What is the nature of Dark Matter and Dark Energy? How are they distributed in the Universe and what role do they play?
Are there other planets like Earth, and solar systems like ours? Are there other habitable worlds?
Are we alone or is there other life somewhere?
How do planets, solar systems, and galaxies form and evolve?
Some of the Super Telescopes will be on Earth, some will be in space. Some have enormous mirrors made up of individual, computer-controlled segments. The Thirty Meter Telescope has almost 500 of these segments, while the European Extremely Large Telescope has almost 800 of them. Following a different design, the Giant Magellan Telescope has only seven segments, but each one is over 8 meters in diameter, and each one weighs in at a whopping 20 tons of glass each.
Some of the Super Telescopes see in UV or Infrared, while others can see in visible light. Some see in several spectrums. The most futuristic of them all, the Large Ultra-Violet, Optical, and Infrared Surveyor (LUVOIR), will be a massive space telescope situated a million-and-a-half kilometers away, with a 16 meter segmented mirror that dwarfs that of the Hubble, at a mere 2.4 meters.
Some of the Super Telescopes will discern the finest distant details, while another, the Large Synoptic Survey Telescope, will complete a ten-year survey of the entire available sky, repeatedly imaging the same area of sky over and over. The result will be a living, dynamic map of the sky showing change over time. That living map will be available to anyone with a computer and an internet connection.
We’re in for exciting times when it comes to our understanding of the cosmos. We’ll be able to watch planets forming around young stars, glimpse the earliest ages of the Universe, and peer into the atmospheres of distant exoplanets looking for signs of life. We may even finally crack the code of Dark Matter and Dark Energy, and understand their role in the Universe.
Along the way there will be surprises, of course. There always are, and it’s the unanticipated discoveries and observations that fuel our sense of intellectual adventure.
The Super Telescopes are technological masterpieces. They couldn’t be built without the level of technology we have now, and in fact, the development of Super Telescopes help drives our technology forward.
But they all have their roots in Galileo and his simple act of observing with a 2-inch telescope. That, and the curiosity about nature that inspired him.