Glenn

sci-fi...art, astronomy, nature, robots,

[Don Pettit @astro_Pettit]

Miami, Florida as seen from the ISS in 2025. This city has changed tremendously since my previous mission, replacing its yellow-orange sodium vapor lights with multi-colored LEDs. The city grid really pops! This LED takeover of city lighting is world wide.

[Don Pettit @astro_Pettit]

I have spent 23 years documenting the global LED transition of city lighting from space.

Across my 4 missions to the ISS, I have photographed every major city on Earth, building a data set of the gradual replacement of sodium vapor lighting with LEDs.

The warmer, yellow-orange of gas discharge lamps has been phased out worldwide to multi-colored LEDs, citing energy savings and environmental reasons.

Widespread adoption has markedly changed the way our cities look from orbit, and as many have pointed out, how they feel to those on the ground!

Here is a collection of the most striking before-and-after photos I have observed:

[NASA Solar System @NASASolarSystem]

A partial lunar eclipse darkens the full Moon on Aug. 27. About 96% of the Moon slips into Earth's shadow, turning most of it red as our atmosphere filters sunlight. Begins 10:34pm ET Aug. 27, peaks 12:12am ET Aug. 28. What to look for: https://t.co/dlWHsPw8Zx 🌙

🎬: NASA's Scientific Visualization Studio/Ernie Wright

[Glenn @Toonforward]

#Procreate #Gemini #ProcreateDreams

[Glenn @Toonforward]

#Procreate #Gemini

[Math Files @Math_files]

In 1772, the great Swiss mathematician Leonhard Euler found something beautiful and surprising.

He discovered that the simple formula

f(x) = x² + x + 41

produces prime numbers again and again.

If you put in whole numbers starting from x = 0 up to 39, every answer is a prime number.

Imagine Euler’s excitement — a neat little formula that keeps giving primes like magic.

But then came the disappointment.

When x = 40, the spell breaks. The result is no longer prime — it’s a composite number. The magic doesn’t last forever.

Still, the formula is remarkable. Even for values from x = 40 to 79, it produces 33 prime numbers.

That’s an impressively high success rate for such a simple expression.

Mathematicians later searched for even better formulas. One powerful example is:

2x² − 199

For the first 1,000 values of x, this formula produces 598 prime numbers — more than any other quadratic formula discovered so far.

These formulas don’t create an endless stream of primes. But they reveal something fascinating: hidden patterns inside numbers.

And sometimes, with nothing more than a pencil and a clever idea, mathematics feels almost magical.

[Glenn @Toonforward]

@TheRealBuzz @usairforce Very Cool 😎

[Glenn @Toonforward]

https://t.co/eS4pGbZyXZ

Abundant

Fuel Efficiency

waste is less problematic than that from uranium reactor

[Glenn @Toonforward]

https://t.co/MfJVB2KBEb

[Hubble @NASAHubble]

Ready for Hubble's largest ever mosaic?

Over the course of a decade, scientists compiled 600+ images of our nearest major galactic neighbor, Andromeda.

This 2.5-billion-pixel image allows astronomers to study Andromeda in meticulous detail: https://t.co/qBH7LcfYR7

#AAS245

[Andrew McCarthy @AJamesMcCarthy]

This is a real photo captured from Earth. This is Mars the moment it emerged after being occulted by the moon, captured with my 14” telescope and formatted as a mobile wallpaper if you want it.

I’m posting my work as mobile wallpapers daily, I’ll do another tomorrow. Stay tuned!

[Glenn @Toonforward]

https://t.co/uG4RP4j22t

[Dr. Buzz Aldrin @TheRealBuzz]

I can’t believe that the @usairforce F-16 Fighting Falcon has been flying for 50 years. I had a chance to fly in one a few years ago with the excellent @AFThunderbirds. It is an amazing and agile plane – sleek and sharp and has definitely aged well. Time certainly flies – as fast as jet aircraft!! Happy #Viper50

[The SETI Institute @SETIInstitute]

#PPOD: When does #Mars act like a liquid? Although liquids freeze and evaporate quickly into the thin atmosphere of Mars, persistent winds may make large sand dunes appear to flow and even drip like a liquid. Credit: @HiRISE MRO @UArizonaLPL @NASA (via @apod)

[Massimo @Rainmaker1973]

The James Webb Space Telescope observed 19 nearby face-on spiral galaxies in near- and mid-infrared light.

These are the new stunning photos.

[read more: https://t.co/Aw7od187Ay]

[Andrew McCarthy @AJamesMcCarthy]

Hubble just dropped some amazing new photos. This one of Ganymede transiting Jupiter reminded me of one I shot in September, so I thought I’d compare. Still can’t compete with a space telescope, but getting closer!

[Glenn @Toonforward]

Nicely written article. #SolarPowered #firstinspires https://t.co/ZOmRisuTLG

[Glenn @Toonforward]

https://t.co/OUXTh2hcue