Astronomy Knowledge Hub

The Night Sky, Explained — by Dmitry Shteynbuk.

A visual knowledge hub for stargazing, the solar system, stellar physics, telescopes, and the history of how we mapped the universe.

HORIZONCELESTIAL EQUATORECLIPTIC · 23.5°RA / DEC GRIDEARTHPOLARIS · NCP
Fig. The celestial sphere · the coordinate system of the sky.
Nightly logbook

Tonight from Dmitry Shteynbuk

All posts →
  1. 01Dmitry Shteynbuk — How Henrietta Leavitt Measured the Universe
  2. 02Dmitry Shteynbuk — Averted Vision: The Observing Trick Built into Your Retina
  3. 03Dmitry Shteynbuk — What Is a Light-Year, Really? (Answered)
The Knowledge Hub

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howto

Learning the Sky: Five Constellations That Anchor Everything

A stepwise plan for actually learning the night sky. Start with five anchor constellations and use them to find everything else — season by season.

Dmitry Shteynbuk··6 min
/articles/learning-the-sky
concept

Magnitude: How Astronomers Measure Brightness

The logarithmic magnitude scale — why lower numbers mean brighter, what the actual math is, and how to use it under real sky conditions.

Dmitry Shteynbuk··7 min
/articles/magnitude-brightness
concept

The Celestial Sphere: How the Sky Is Organized

The imaginary sphere astronomers use to describe positions in the sky — poles, equator, ecliptic, and coordinates — explained in plain language.

Dmitry Shteynbuk··6 min
/articles/celestial-sphere
guide

Comets, Asteroids, and Meteors: What's the Difference?

Three small-body categories that get confused constantly, with clear definitions and the real numbers on size, orbit, and composition.

Dmitry Shteynbuk··6 min
/articles/comets-asteroids-meteors
concept

The Moon's Phases, Finally Explained Properly

The phases of the Moon are pure geometry: the Sun lights one hemisphere, and we see how much of that hemisphere from a different angle each night.

Dmitry Shteynbuk··6 min
/articles/moon-phases
concept

Why Orbits Work: Kepler's Three Laws in Plain Language

The three laws that describe every orbit in the solar system — stated in words, backed with real numbers for the planets, and grounded in Newton's gravity.

Dmitry Shteynbuk··6 min
/articles/keplers-laws
Glossary

A working vocabulary of the sky

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25° North · Miami, Florida

Dark skies at the edge of the tropics.

The Everglades and Big Cypress preserves hide some of the darkest skies in the eastern United States, and the Florida Keys open a clean horizon straight south over the Atlantic. From the Miami coast you can watch Cape Canaveral launches arc up out of the northern sky, and at 25° north the far southern constellations — Centaurus, Crux at its lowest — briefly clear the horizon in a way they never do from the rest of the mainland.

Miami, Florida
About the author

Dmitry Shteynbuk — Miami, Florida

I'm an astronomy educator based in Miami. I write and illustrate plain-language guides to the night sky — the kind of explanations I wish I'd had when I first tried to figure out what I was looking at.

The site is organized as a knowledge hub rather than a news feed: eight subject areas from naked-eye stargazing through the history of astronomy, each built from short guides, diagrams, and a nightly logbook of what's currently up.

My angle is South Florida — 25° north, warm humid nights, mangrove-dark preserves an hour from the city, and a working coastline that lets us watch rockets launch from Cape Canaveral. Most of what's here works anywhere, but Miami is where I actually observe from.