﻿You’ve probably seen images from the James Webb Space Telescope –
those intricate portraits of deep space that spark our imagination.
But here on Earth, a new ground-based observatory
has started capturing images that are every bit as extraordinary.
If you watched my video in 2020 about the most exciting telescope that nobody was talking about,
then you may remember just how thrilled I am about the Vera C. Rubin Observatory.
Perched atop the Cerro Pachón mountain in Chile,
this observatory just captured its first ever images with help
from the largest digital camera ever built.
This camera, roughly the size of a small car and weighing around 2,800 kilograms,
boasts an astonishing 3.2 billion pixels per image.
To put that in perspective, it would take you about 385 4K televisions
to display just one of the photos from this telescope…
that is a staggering amount of data.
In fact, the survey can collect around 20 terabytes of data in a single night.
Since the observatory is located in Chile and the data centre is in the United States,
a dedicated 100 Gbit internet connection was built to connect the facility to Miami, Florida,
where it taps into the existing infrastructure.
The first official images were released in June 2025,
and in my opinion, they’re among the most breathtaking astronomical images I’ve ever seen.
And this is just the beginning.
So what do these first images show us? How were they taken?
And what will astronomers be hoping to learn from this ambitious project in the years ahead?
I’m Alex McColgan, and you are watching Astrum.
Join me today as we unveil these stunning images
and explore how this groundbreaking observatory could transform our view of the universe.
Although some operations have begun,
final testing is expected to wrap up by late 2025.
And just as this facility is destined to become a legend in modern astronomy,
it carries the name of a woman who was a legend in her own right. In the 1960s – when women were
rarely seen in astronomy – Dr. Rubin was credited with discovering the first compelling evidence for
the existence of dark matter. And she did so while balancing both her career and motherhood. It’s
fitting that such a pioneering observatory bears the name of an equally pioneering astronomer.
And like its namesake, the Rubin Observatory will not disappoint.
Part of what makes images so crisp from space telescopes like Hubble and Webb is their vantage
point from outside of Earth’s atmosphere. From space, they are able to avoid the distortion
of weather and light pollution, issues that typically plague ground-based telescopes.
That’s exactly why the Rubin Observatory was built on a mountain in the Atacama Desert of Chile,
giving it one of the best observing locations anywhere on Earth. Its extremely dry air and
dark skies make for the perfect conditions for ground-based astronomy. And the new observatory
isn’t alone: the area is also home to several other observatories, including the Southern
Astrophysical Research Telescope, the Gemini South Observatory, the Giant Magellan Telescope,
and the European Extremely Large Telescope. This location has proven itself time and
again as an exceptional observing spot. Interestingly, the Rubin Observatory isn’t
run by a major space agency like NASA or ESO. Instead, it’s funded by the United States’
National Science Foundation and Department of Energy, and is managed by the Association
of Universities for Research in Astronomy. Inside the Rubin Observatory is the Simonyi
Survey Telescope, which became the seventh largest telescope in the world when it was completed. Its
primary mirror spans 8.4 metres, with a 3.5-metre secondary mirror, but size isn’t everything.
What makes it truly unique is its third, 5 metre mirror. Most telescopes use a two-mirror system to
focus light and correct optical distortions that can come from the curve of the mirror,
but the Simonyi Survey Telescope uses three, giving it an extraordinarily sharp view.
Attached to the end of this powerful telescope, is an equally impressive
camera to record what the telescope sees. It’s the largest camera ever constructed,
measuring about 3 metres long and 1.6 metres wide. Designed to capture ultraviolet, visible,
and near-infrared light, it uses a robotic arm to place filters in front of its sensors.
Named after the Legacy Survey of Space and Time, or the LSST, the camera will
support this decade-long sky survey. The LSST camera is made up of 189
individual sensors and outfitted with three large fused-silica lenses. Each exposure covers
10 square degrees of the sky, giving it superb optical performance. That is quite a wide angle
of visibility: one single image can capture an area of the sky equal to about 45 full moons.
If you compare these stats to previous surveys like the Sloan Digital Sky Survey,
the LSST is essentially doing every 3 days what SDSS took 20 years to do. SDSS steadily built up
a map covering 35% of the sky over its 20 year run, but the LSST can map the entire visible sky
in the Southern Hemisphere, or 50%, with every 3-day scan. The 10-year duration of the LSST is
not strictly to cover a wider area of sky, but to map our cosmos in a temporal dimension, building
a searchable timelapse movie of the sky and tracking its changes over time like never before.
Like any sky survey, the LSST is meant to look for anything and everything in the night sky. However,
it does have four main scientific goals: to investigate dark matter and dark energy,
to catalogue solar system objects like asteroids and comets, to monitor transient events like
supernovae, variable stars, and gamma-ray bursts, and to map the stars of the Milky Way.
Surveys like Gaia, Pan-STARRS, DESI, and Sloan paved the way, but Rubin will take
things further. For example, it’s expected that data from Rubin will allow us to
identify millions of new asteroids – vastly expanding our catalogue and creating a dataset
unlike anything we’ve ever had before. Luckily for us, we won’t have to wait
10 years to see what this new observatory has in store! The LSST team will release
images throughout the project, letting the world follow along as discoveries unfold.
As mentioned earlier, the first of these images were released just in June 2025,
and I think you’re going to love them. After just over 10 hours of test observations,
the Rubin Observatory had already captured cosmic phenomena on an unprecedented scale.
Millions of stars and galaxies, thousands of asteroids… and these images represent
just a small preview of what’s to come. What you are now seeing is one of the first
images ever released by the Rubin Observatory, dubbed the “Cosmic Treasure Chest.” Made up of
1,185 exposures taken over seven nights, it shows a region in the southern Virgo Cluster,
about 55 million light-years away. It’s the closest large cluster of galaxies to our own.
This 25-square-degree mosaic reveals an astonishing variety of stars and
galaxies. It combines multiple exposures of the same area, each taken at different
times and with different filters to reveal faint details that may otherwise go unseen.
Let’s zoom in to a few highlights. In the upper left, two prominent spiral galaxies dominate the
view, with a trio of merging galaxies just above them. Threads of material stretch between them,
and both nearby and distant galaxy groups populate the scene, along with a few
foreground stars from our own Milky Way. On the opposite side of the image is an
extraordinarily dynamic area nicknamed “Cosmic Drama.” Here, bright stars from our galaxy
shine in the foreground, with dozens of nearby galaxies clearly visible, and a distant sea of
reddish galaxies forming a speckled backdrop. This image contains some 10 million galaxies.
And that represents just 0.05% of the 20 billion galaxies that the Rubin Observatory
is set to observe over the next decade. Another early image is this striking mosaic of
two nebulae taken over just seven hours and made up of 678 individual images. In a single exposure,
the dust and clouds that make up these nebulae may be faint or invisible, but by combining hundreds
of exposures, these details become clearer. At the center of the mosaic is the Lagoon Nebula,
or Messier 8, situated about 5,200 light-years from Earth. This kidney-bean-shaped pink area is
one of only a few star-forming nebulae that are visible with the naked eye,
although faintly, in mid-northern latitudes. If you were to look at this nebula through
a telescope or binoculars, you would see what looks like a spot of grayscale clouds.
This is because the human eye can only detect certain wavelengths of light – but the Rubin
Observatory is able to capture a broader range. These additional wavelengths can be added into
the picture as different colours. For example, in this image, the infrared
light typically associated with cooler objects is assigned the colour red, while the warmer
ultraviolet wavelengths are assigned to blue. For comparison, here is an optical image of the
same Lagoon Nebula taken by NASA’s Hubble Space Telescope in 2018. As you can see,
the Hubble image is rich in detail, and similarly, uses various added colours to
represent information that the human eye can’t see on its own. In this case, the colours represent
different particles detected across the image. You might also notice that this Hubble image is
very close-up - it’s only about 4 light years across. However, the Rubin Observatory gives a
much wider view of the Lagoon Nebula. In fact, the difference is shocking.
The Lagoon Nebula is a staggering 55 light-years across and 20 light-years tall - yet takes up only
a fraction of the Rubin image. Why is there such a difference? Well, Hubble is designed to focus
on individual objects. With its 2.4-metre primary mirror, it can capture 16.8 megapixel images of
individual objects. But the Rubin Observatory’s 8.4-metre primary mirror and 3.2 billion megapixel
camera were built to photograph gigantic sections of the sky, in exceptional detail.
Hubble’s field of view is able to see the equivalent of about one percent of our Moon’s
surface area in a single image. But Rubin has a field of view wide enough to see 40
times the moon’s surface area in one exposure. That means the Rubin Observatory can photograph
four thousand times the area of sky that Hubble can in a single
image. That’s part of what makes it so special. Let’s take another look at the Rubin mosaic image.
Not only does this wide field of view show the entire Lagoon Nebula,
but we can also identify several other objects. At the top, you can spot a swarm of blue lights,
this is an open star cluster known as Messier 21. Just below that,
the pink-and-blue glow of the Trifid Nebula, also known as Messier 20, sits about 9,000 light-years
away in the constellation Sagittarius, and can sometimes be spotted with small telescopes.
Directly below that is another open star cluster known as Bochum 14, and towards the
bottom center of the mosaic image is a tightly packed globular cluster known as NGC 6544,
which is home to tens of thousands of stars. The sheer number of stars and galaxies visible
in these images is staggering. And to think that on the larger mosaic image,
this globular cluster is just a tiny speck. And it’s not just pretty images – the
Rubin Observatory is already producing real scientific results.
In just about 10 hours, the observatory was able to identify 2,104 asteroids in our
solar System that had never been seen before, including seven near-Earth asteroids, which,
you’ll be happy to hear, pose no threat to us. For comparison, about 20,000 new asteroids are
identified every year through the combined effort of all other ground- and space-based
observatories. Rubin alone is expected to discover millions of new asteroids within
its first two years of operation. It may also be our best tool yet for spotting
interstellar visitors passing through the Solar System, like ʻOumuamua or 2I/Borisov.
Astronomers estimate that interstellar visitors like these pass through our inner solar system
about once a year, but we’ve only recently gotten survey telescopes capable of spotting them, like
the Pan-STARRS1, and now, the Rubin Observatory. And that’s not all. The observatory also spotted
46 subtly pulsating stars, known as RR Lyrae stars, a type of ancient, pulsating star that are
often used to measure distance. Over the course of the survey, Rubin is expected to find up to
100,000 more of these stars, with some potentially stretching more than a million light-years from
Earth. By finding these stars, Rubin can help astronomers to map the outer reaches
of our Milky Way and explore its structure. In its first year alone, Rubin will collect
more optical data than all previous observatories combined. By the end of
the survey, it’s expected to generate around 500 petabytes, or 500,000 terabytes, of data,
containing billions of objects and trillions of measurements - a true goldmine for researchers.
Once final testing is complete, the Rubin Observatory will repeatedly
scan the southern sky, capturing fleeting cosmic events in real time, while building
a decade-long time-lapse of the universe. I don’t know about you, but I am already
blown away by these early images, and the real survey hasn’t even started
yet. I can’t wait to see what comes next! If you liked this video, there is another
exciting telescope that has just begun work - Euclid. Check out its first light images here!
And if you’d like, you can explore Rubin’s images for yourself by visiting skyviewer.app.
It’s a lot of fun to zoom in on some of these images. I’d highly recommend it.
Combing through 500 petabytes of data hunting for rare cosmic events is not for the faint of heart.
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