Observational Astronomy in Overdrive

 The Trifid and Lagoon nebulae. The first released image from the Vera C. Rubin Observatory. Credit:NSF–DOE Vera C. Rubin Observatory

Amidst the doom and gloom that defines our present age, have you ever stopped to consider that we're living in an era of unprecedented astronomical discovery?

Today, a greater number of professional astronomers are observing the cosmos than ever before, with over 12,000 active researchers globally, as reported by the IAU, which is almost six times the number from fifty years ago. There are more observatories both on Earth and in orbit, more robotic probes exploring the solar system, and more computing power analysing the astounding wealth of data being collected daily from space. And still, all this pales in comparison to what lies ahead, as new instruments worthy of science fiction are making their appearance.

Before we look ahead, it is worth remembering that an important chapter in space observation was in the 1990s-2000s when the third generation of ground-based telescopes had arrived (e.g., Kecks, VLT, Gemini, Subaru, etc.), in addition to new space-based observatories (e.g., Hubble Telescope, COBE, and Chandra). These brought in surprising discoveries (dark energy) and ground-breaking research (exoplanet imaging). We are now entering a new age, where awe-inspiring observatories are seeing light; these are not mere upgrades but, instead, mark a tectonic shift—each bringing observational astronomy into new orders of magnitude.

For a start, Gravitational wave astronomy, which began in earnest in 2015—already a decade ago!—has introduced a novel method of observing space that, remarkably, doesn't rely on measuring electromagnetic energy, such as light. While the initial detections of the LIGO Observatory amazed the world, these were constrained by the limitations of the technology and the sensitivity of the instruments. New, more sensitive gravitational observatories have appeared, such as New LIGO, or are in the works, such as ESA's LISA or Japan's KAGRA. Another mission which ushered us into the new era, the space observatory Gaia, has mapped out a billion astronomical objects with unprecedented precision after ten years of hard work. And then, of course, the James Webb Space Telescope finally saw light in July 2022, and in such a short space of time, the JWST has already peered through the early universe and examined the atmospheres of Earth-like exoplanets.

As if these were not amazing enough already, new Earth-based observatories are arriving. The Vera C. Rubin Observatory, with its 3.2-gigapixel camera, will soon begin the Legacy Survey of Space and Time (LSST) project, which will image the entire southern sky every few nights for a decade. Its first images alone, released a few days ago, revealed over 10 million galaxies, many never seen before, while its first set of images has detected hundreds of new asteroids. Think of the Vera Rubin telescope as a GoPro; capturing nightly time-lapse reels of the universe in motion. The data collected will be immense as the camera is expected to take more than 200,000 pictures (1.28 petabytes uncompressed) per year. I can barely contain my excitement at the thought of millions of asteroids and other small planetary objects being uncovered in our Solar System.

And then, there's the advent of colossal observatories built on a scale never before conceived. Among the most ambitious is the Extremely Large Telescope (ELT), currently taking shape in Chile under ESO (European Southern Observatory). With an awe-inspiring mirror diameter of 39 meters, it will be the largest optical/infrared telescope in the world once operational in just a couple of years (the largest telescope currently in operation is the Gran Telescopio Canarias at 10.4 meters). Joining this generational leap is the Giant Magellan Telescope (GMT), also being assembled in Chile, whose array of seven massive mirrors will combine to create a resolving power equivalent to a 24.5-meter single mirror. Designed for profound sensitivity and detail, GMT is expected to begin capturing light in the late 2020s. Meanwhile, the Thirty Meter Telescope (TMT) stands as another contender, although its destiny remains uncertain due to ongoing site negotiations and proposed budget cuts.

Within a decade, we will be observing the universe in ways that, just twenty years ago, would have belonged to the realm of fantasy.  Seriously—if this doesn’t blow your mind, what will? We live in extraordinary times.

Onwards and upwards.