Stellar Realm
@watchstellarrealm.bsky.social
How the universe works. Told properly.
Documentaries on stars, supernovae and black holes, built on real NASA, ESA and ESO imagery, with every fact checked against published science.
Narration and music are AI-generated; the science is not.
Documentaries on stars, supernovae and black holes, built on real NASA, ESA and ESO imagery, with every fact checked against published science.
Narration and music are AI-generated; the science is not.
If the Sun vanished right now, you'd have 8 more minutes of sunshine. And Earth would keep orbiting nothing for those same 8 minutes: gravity travels at the speed of light too.
Image credits in the YouTube description.
AI narration and music.
Image credits in the YouTube description.
AI narration and music.
October 14, 2026 at 7:01 PM
If the Sun vanished right now, you'd have 8 more minutes of sunshine. And Earth would keep orbiting nothing for those same 8 minutes: gravity travels at the speed of light too.
Image credits in the YouTube description.
AI narration and music.
Image credits in the YouTube description.
AI narration and music.
The Sun is 150 million km away.
The sunlight reaching you now left it 8 minutes and 20 seconds ago.
The sunlight reaching you now left it 8 minutes and 20 seconds ago.
October 14, 2026 at 12:00 PM
The Sun is 150 million km away.
The sunlight reaching you now left it 8 minutes and 20 seconds ago.
The sunlight reaching you now left it 8 minutes and 20 seconds ago.
On 18 November 2026, Voyager 1 becomes the first human-made object one light-day from Earth. 49 years of flying. A radio message will take a full day to reach it.
Image credits in the YouTube description.
AI narration and music.
Image credits in the YouTube description.
AI narration and music.
October 13, 2026 at 7:01 PM
On 18 November 2026, Voyager 1 becomes the first human-made object one light-day from Earth. 49 years of flying. A radio message will take a full day to reach it.
Image credits in the YouTube description.
AI narration and music.
Image credits in the YouTube description.
AI narration and music.
Light travels almost 300,000 km every second.
That's fast enough to go around the Earth seven and a half times in one second, and it's the ruler we use to measure the universe.
That's fast enough to go around the Earth seven and a half times in one second, and it's the ruler we use to measure the universe.
October 13, 2026 at 12:00 PM
Light travels almost 300,000 km every second.
That's fast enough to go around the Earth seven and a half times in one second, and it's the ruler we use to measure the universe.
That's fast enough to go around the Earth seven and a half times in one second, and it's the ruler we use to measure the universe.
New film: How Big Is the Universe, Really?
13.8 billion years old, yet we can see more than 90 billion light-years across it. Here's how.
13.8 billion years old, yet we can see more than 90 billion light-years across it. Here's how.
October 12, 2026 at 4:05 PM
New film: How Big Is the Universe, Really?
13.8 billion years old, yet we can see more than 90 billion light-years across it. Here's how.
13.8 billion years old, yet we can see more than 90 billion light-years across it. Here's how.
13.8 billion years old.
More than 90 billion light-years across.
Both true. Tonight at 18:00 UK, a new Stellar Realm film shows how.
More than 90 billion light-years across.
Both true. Tonight at 18:00 UK, a new Stellar Realm film shows how.
October 12, 2026 at 11:00 AM
13.8 billion years old.
More than 90 billion light-years across.
Both true. Tonight at 18:00 UK, a new Stellar Realm film shows how.
More than 90 billion light-years across.
Both true. Tonight at 18:00 UK, a new Stellar Realm film shows how.
You are made of star-stuff. The iron in your blood was made by stars. Not a metaphor.
Images: ESA/Hubble, NASA, ESO, ALMA (CC BY 4.0), Pexels.
AI narration and music.
Images: ESA/Hubble, NASA, ESO, ALMA (CC BY 4.0), Pexels.
AI narration and music.
October 10, 2026 at 12:01 PM
You are made of star-stuff. The iron in your blood was made by stars. Not a metaphor.
Images: ESA/Hubble, NASA, ESO, ALMA (CC BY 4.0), Pexels.
AI narration and music.
Images: ESA/Hubble, NASA, ESO, ALMA (CC BY 4.0), Pexels.
AI narration and music.
New film: The Day the Engine Dies.
Every massive star is an engine balanced on a knife-edge, and its last fuel lasts about a single day. The full story:
Narration and music are AI-generated; the science is sourced.
Every massive star is an engine balanced on a knife-edge, and its last fuel lasts about a single day. The full story:
Narration and music are AI-generated; the science is sourced.
October 8, 2026 at 5:05 PM
New film: The Day the Engine Dies.
Every massive star is an engine balanced on a knife-edge, and its last fuel lasts about a single day. The full story:
Narration and music are AI-generated; the science is sourced.
Every massive star is an engine balanced on a knife-edge, and its last fuel lasts about a single day. The full story:
Narration and music are AI-generated; the science is sourced.
Inside a neutron star's crust, nuclei squash into shapes physicists named after pasta: gnocchi, spaghetti, lasagna.
Simulations suggest this 'nuclear pasta' may be the strongest material in the universe, about ten billion times stronger than steel.
Simulations suggest this 'nuclear pasta' may be the strongest material in the universe, about ten billion times stronger than steel.
October 8, 2026 at 3:30 PM
Inside a neutron star's crust, nuclei squash into shapes physicists named after pasta: gnocchi, spaghetti, lasagna.
Simulations suggest this 'nuclear pasta' may be the strongest material in the universe, about ten billion times stronger than steel.
Simulations suggest this 'nuclear pasta' may be the strongest material in the universe, about ten billion times stronger than steel.
Three stars you can see with your own eyes will one day explode: Betelgeuse (Orion's red shoulder), Rigel (his blue-white foot) and Antares (the heart of the Scorpion).
Betelgeuse could go tomorrow, or in 100,000 years. Nobody knows.
Image: Y. Beletsky (LCO)/ESO, CC BY 4.0
Betelgeuse could go tomorrow, or in 100,000 years. Nobody knows.
Image: Y. Beletsky (LCO)/ESO, CC BY 4.0
October 8, 2026 at 2:00 PM
Three stars you can see with your own eyes will one day explode: Betelgeuse (Orion's red shoulder), Rigel (his blue-white foot) and Antares (the heart of the Scorpion).
Betelgeuse could go tomorrow, or in 100,000 years. Nobody knows.
Image: Y. Beletsky (LCO)/ESO, CC BY 4.0
Betelgeuse could go tomorrow, or in 100,000 years. Nobody knows.
Image: Y. Beletsky (LCO)/ESO, CC BY 4.0
Squeeze a giant star's life into 80 years.
Hydrogen: about 70 years. Helium: 9. Carbon: a couple of days. Neon and oxygen: minutes.
And silicon, its last fuel: about one second.
Hydrogen: about 70 years. Helium: 9. Carbon: a couple of days. Neon and oxygen: minutes.
And silicon, its last fuel: about one second.
October 8, 2026 at 12:30 PM
Squeeze a giant star's life into 80 years.
Hydrogen: about 70 years. Helium: 9. Carbon: a couple of days. Neon and oxygen: minutes.
And silicon, its last fuel: about one second.
Hydrogen: about 70 years. Helium: 9. Carbon: a couple of days. Neon and oxygen: minutes.
And silicon, its last fuel: about one second.
One gram of matter, the mass of a paperclip, holds about 25 million kilowatt-hours if every bit of it could be turned into energy. Enough to power about 9,000 homes for a year.
That is E = mc², and it is why stars can shine for billions of years.
That is E = mc², and it is why stars can shine for billions of years.
October 8, 2026 at 11:00 AM
One gram of matter, the mass of a paperclip, holds about 25 million kilowatt-hours if every bit of it could be turned into energy. Enough to power about 9,000 homes for a year.
That is E = mc², and it is why stars can shine for billions of years.
That is E = mc², and it is why stars can shine for billions of years.