The Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey has recorded more than one billion galaxies.

But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

> But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

A bit less officially, need to remove one zero [1]

[1] https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estim...

There are more recent estimates going from 6-20 trillion now: https://bigthink.com/starts-with-a-bang/galaxies-in-universe...

That article is going beyond the observable universe, other comments were talking about within it.

What makes you think that? I quote:

> "Instead, based on what we see around nearby Milky Way analogues, there ought to be at least 6 trillion galaxies contained within the observable Universe, and it’s plausible that a number that’s more like ~20 trillion"

Yeah, the scale of it is absolutely mind-blowing

And to think I assumed Astronomy was a stagnant field some decades ago. I have no idea why I thought that. Maybe that optical resolution from ground-based telescopes was not going to advance orders of magnitudes? Maybe I didn't think the sciences would continue to get money for space telescopes?

Astronomy has been in a golden age for the last 35 years, based on:

1. Digital cameras, and the computers to analyze images.

2. Space telescopes (Hubble Space Telescope, the first large space telescope, only launched in 1990).

3. The building of massive ground-based telescopes. Before 1990, the largest telescope had a mirror diameter of 6 meters. Now, multiple 30-meter telescopes are under construction. Collecting power goes with the square of the diameter, so this is an increase of 25 times in collecting power!

4. Very recently, the development of gravitational-wave interferometers, which allow astronomers to observe a totally new type of radiation.

To add to the list (the order is arbitrary):

5. Advances in the multi-messenger observations, where apart of photons and gravitational waves, astronomers can detects also neutrinos with specialized neutrino detectors, e.g.: IceCube [a], though there are many more of those [b].

6. Advances in very-long-baseline interferometry [c] using a globe-sized array of radio-telescopes, like Event Horizon Telescope [d]

[a] https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory

[b] https://en.wikipedia.org/wiki/Neutrino_detector or here https://en.wikipedia.org/wiki/List_of_neutrino_experiments

[c] https://en.wikipedia.org/wiki/Very-long-baseline_interferome...

[d] https://en.wikipedia.org/wiki/Event_Horizon_Telescope

And one more:

7. The LISA mission is underway to build a space-based detector for gravitational waves at the 0.1hz region, whereas LIGO is sensitive around the 500hz region. 500hz corresponds to inspiraling stellar mass black holes. 0.1hz corresponds to inspiraling supermassive black holes. Think about the most powerful subwoofer the laws of physics allow, given the maximum amount of mass density in a volume and the speed of light.

https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Ant...

It's pretty wild how much astronomy has progressed, especially with advancements in adaptive optics, interferometry, and space telescopes. Even ground-based observatories have improved way beyond what most people would've expected a few decades ago

I feel infinitesimally small.

Yeah, same here. It's a humbling feeling... realizing how tiny we are in the grand scheme of things. But also kind of amazing that, despite our smallness, we've figured out how to explore and understand the universe at this scale

me too, but big things have small beginnings!