David Suárez

Biólogo que no ejerce de tal. Trader a tiempo parcial. Siempre intentando aprender. Aficionado a muchas cosas, y entre ellas, volar. Devoto del pulpo a feira.

[David Suárez @dasufab]

“Entre lusco e fusco”, detailed explanation …https://t.co/yTiyl4K2BN

[Erika  @ExploreCosmos_]

Twilight vs. Dusk & Dawn

Have you ever noticed how the sky doesn’t go dark immediately after sunset or instantly brighten before sunrise? That beautiful in-between light is called twilight, a magical period when the Sun is just below the horizon, scattering light through Earth's atmosphere and painting the sky in soft pastels.

What Is Twilight?

Twilight is not a single moment but a transitional phase between day and night. It happens after sunset and before sunrise, when sunlight is still bouncing around the atmosphere, even though the Sun itself isn't visible. It's the reason you can still see without artificial lights just after the Sun disappears.

Twilight is divided into three phases, depending on how far the Sun is below the horizon:

1. Civil Twilight (0° to 6°).

This is the brightest twilight phase. The horizon is still clearly visible, and only the brightest stars and planets can be seen. This is when most people would still feel like it’s “almost day,” though street lights might start to flicker on.

2. Nautical Twilight (6° to 12°).

Now, the horizon starts to blur. It’s dark enough for sailors to spot stars for navigation, but there’s still a soft light in the sky. It’s a favorite time for photographers to capture silhouettes and glowing cityscapes.

3. Astronomical Twilight (12° to 18°).

The sky becomes nearly dark. This is when deep-sky objects like galaxies and the Milky Way become visible to the naked eye or a camera. We prefer this phase for serious stargazing or astrophotography.

What About Dusk and Dawn?

While twilight refers to a gradual transition, dusk and dawn are precise moments in time.

Dawn marks the beginning of twilight before sunrise. It comes in three stages: astronomical dawn, nautical dawn, and civil dawn, depending on how far the Sun is below the horizon.

Dusk marks the end of twilight after sunset. Just like dawn, it has civil dusk, nautical dusk, and astronomical dusk.

So, if twilight is the journey, dusk and dawn are the milestones.

Fun Fact:

The length of twilight depends on where you are on Earth. Near the Equator, twilight zooms by in just 24 minutes. But near the poles, especially around the solstices, twilight can linger for hours, or even weeks

[David Suárez @dasufab]

Supongo que les gustará a @AlbertoPereiro y a @JuanraLucas . Cuando hacían la transición de La Brújula a Deportes a las 20:30h solían poner a Miley cada vez que podían… 😊😊

[Sebastián Puig ⚓ @Lentejitas]

Lo mejor de esta noche es ver a Miley Cyrus interpretando con Metallica su mítico “Nothing Else Matters”. La magnífica voz de Miley y su calidad en esos bajos impresionantes. El respeto que muestra quedándose detrás de Hetfield aunque sea la cantante principal en esta versión ❤️

[El Club del Arte 🎨📷📚🖼🕍🎼 @Arteymas_]

Cuando naces con la música por dentro. 🎶

[Jerry Pike @JerryPikePhoto]

Falcon Heavy transits the 98.2% illuminated moon on its way to space with the X-37B mini-shuttle

[Marcos Antón Renart @marcosantonr]

👏🏼 Otro gran vídeo de @RodenasAlicia, ahora con motivo del Día de la Hispanidad. Enhorabuena Alicia!

📷 vía @gerebit0 #12octubre #DíadelaHispanidad

[David Suárez @dasufab]

Exacto!

[Judge the Zipper @JudgeTheZipper]

Creo que los que aplauden que la universidad sancione a unos alumnos por las cosas que han rebuznado por whatsapp no se dan cuenta que están justificando que se nos revisen a todos nuestros mensajes privados por si encuentran algo. A todos. Peligrosa deriva.

[Mick West @MickWest]

We should take pilot reports of UFOs seriously and try to figure out what they are. There should be less stigma.

But reflexively ignoring an obvious explanation like Starlink Horizon Flares is not helping, especially when that explanation is a perfect match for the available data.

Promoting cases like this will increase stigma.

[Ricky Davila @TheRickyDavila]

Ending today with this. Good night. 💚

[RetroPilot @VictorLAyerbe]

Cuàl es el lugar màs bonito para volar? 😬
#galicia

[David Suárez @dasufab]

First anniversary James Webb Space Telescope. Great job!!!

[NASA @NASA]

Here it is: @NASAWebb’s one-year anniversary image. Called Rho Ophiuchi, this area shows about 50 young stars in a cocoon of gas and dust. At 390 light-years away, it's the closest star-forming region to Earth: https://t.co/A3e2XLx9Ef

Webb continues to #UnfoldTheUniverse.

[David Suárez @dasufab]

These are the secrets!

[Melissa Perri @lissijean]

Serious question for people from Spain…

When do you SLEEP?

Been here for a week. Dinner at 10pm (sometimes ELEVEN) and at work by 9am. Weekends people in their 40s and 50s out until 3am.

Are you vampires? How do you do it? What’s the secret?

[David Suárez @dasufab]

@GinieSigonney Quote tweet with a sky pic you’ve taken

[SpaceX @SpaceX]

Fairing reentry on the ViaSat-3 mission was the hottest and fastest we've ever attempted. The fairings re-entered the atmosphere greater than 15x the speed of sound, creating a large trail of plasma in its wake

[David Suárez @dasufab]

😂😂

[KURYER🤔 @RSS_40]

Many ask me to explain how a nuclear reactor works…Well, begin with a nuclear chain reaction. Visually 🤔⬇️

[NASA Webb Telescope @NASAWebb]

Triples is best.

This Webb image features a special galaxy that appears 3 times. Why? There's a galaxy cluster here whose mass and gravity are so great that time and space around it gets warped. This magnifies, multiplies, and distorts galaxies behind it: https://t.co/ftRTPC4bDr

[Gaston Giribet @GastonGiribet]

Cerca del 70% de todo cuanto existe en el universo es una ubicua energía oscura cuya naturaleza nos intriga y cuya composición desconocemos. Otro 25% es una materia oscura, pesante e indiferente que, al parecer, no interactúa con nosotros. El resto frugal es de lo que estás hecho

[Q*bert @Cotidianeous]

Pero qué maravilla es esta?

[David Suárez @dasufab]

@StoneyRita ¡Eso no se lo quita nadie! 👏🏼👍

[Aemilius Bis. @alternateb747]

Dice el autor que esta es la toma que más le gustó del 2022.
También a un servidor.
🔊🎶
📽 LouB747

[David Suárez @dasufab]

El extremo será sentirte mal por la huella de carbono que emites al respirar. A este paso, alguien lo pondrá sobre la mesa…

[EL PAÍS @el_pais]

Con la crisis climática, es normal sentirse mal por contribuir a las emisiones cuando uno se sube a un avión. El filósofo Michael Marder nos ofrece algunas ideas para lidiar con los remordimientos del pasajero https://t.co/uqxUI3KESq