Star Noon 3 of 3: See Sidereal Time in the Sky
Snapshot the midnight sky every night for a year, then play it back as a time lapse movie. What would you see? Here's how to see sidereal time for yourself.
Star In A Star
Learning Astronomy, Teaching Astronomy
Latest posts
Star Noon 2 of 3: Follow Sirius Through the Year
The Sun and the dog star Sirius line up on the meridian together in July. But each day the stars travel a little faster than the Sun. Follow Sirius as it drifts from noon to midnight.
Star Noon 1 of 3: Star Noon and Sun Noon
There are two skies: the sun sky and the starry sky. A clock is a machine tuned to the Sun — but a sidereal clock gets its time from the stars.
16 Laps Around the Galaxy, 20 Laps to Go
Our solar system orbits the center of the Milky Way once every 230 million years. The Earth has completed about 16 laps so far. It has roughly 20 more to go.
Vega–Capella anchor the equinoxes
Use Vega and Capella as anchor stars to aim at the equinox points in the sky. Add Caph for spring, or Phecda and Zavijava for fall.
Fifth Friday and the Full Moon
Let's meet on the fifth Friday of the month, let's make it the next one with a full moon. When exactly is that? How old will I be?
Moon Phases Names - an easy way to remember
The Moon phases names are pretty weird. Here are the "official" 8 Moon Phases in order. Bonus! FREE graphic memory device to help you remember the phases.
Analemma answers the question: "What time is it at noon?"
They say even a broken clock is right twice a day. In the same way, the Sun is “right” four times a year; the analemma shows how. What time is it at noon? What…
Tristram Shandy's sky
The 18th-century English novel "The Life and Opinions of Tristram Shandy, Gentleman" (better known by its nickname _Tristram Shandy_ - first published in 1759)…
Get closer to the Moon without leaving the Earth
How close am I to the Moon right now? As a human on the Earth's surface, learn how you can get closer to the Moon. It's surprising!
GPS uses Quasars
The GPS for GPS. How does GPS know where a GPS satellite is? GPS uses quasars. The base GPS system can't just ask GPS, because GPS is supposed to provide the authoritative positioning data. It would be a catch-22. The answer is that the GPS system is anchored by quasars.
Remember the planets
Remember the order of 8 planets of the Solar System with a mnemonic: My Very Educated Mother Just Served Us Nachos. Mercury, Venus, Earth, etc
Countries in the Sky
A spot on Earth is a spot in the sky. Every "spot" on Earth has a corresponding "spot" in the sky. For instance, on the spot where you are now, directly…
Do Stars Move?
Dalle-2 Generated this image of a figure standing, wondering at the cosmos. Prompt: “gentle, happy 8 year old child, standing in a sunset forest, looking…
there are stars in the daytime sky
to the west of the noonday sun are the stars that were up when the day had just begun. to the east of the sun are the stars that will come out when this very…
How Fast is the Earth Moving? - A Quiz
A family views the visible orbit path of the earth. "How fast?" means "What is our velocity?" Velocity is a speed combined with a direction. We can figure out…
Super Simple Earth Model
Super Simple Earth Model Physical Astronomy by Daniel Cummings Stand outside on a sunny day or in a room with only one light. If you are inside the light…
Galileo's Middle Finger
Galileo's Middle Finger In 1737, Galileo's body was moved from one burial place to another. During the move several of his fingers and a tooth were removed…
Constellations of the Zodiac in Order
Learning the Zodiac constellations in order is a great way to get familiar with the ecliptic and the celestial sphere. The Zodiac is not just for astrology -…
Seeing The Zodiac - A Stellarium Script Tutorial
Read a tutorial for a custom Stellarium script that shows Zodiac constellation art, boundaries, and the ecliptic. Online astronomy presentation with zoom!
Galaxy Horizon - 4/20 at Midnight
On April 20th (4/20) at midnight Earth's horizon (in northern latitudes) lines up perfectly with the plane of the entire Milky Way galaxy. The galaxy "wraps…
Earth Map in the Sky
Earth Map in the Sky - Landforms as Constellations Learn how to _see the map of Earth in the starry sky._ Stars help us find our way. Stars are like a giant…
Sporades - Stars Not Part of Any Constellation
Milky Way behind trees. Photo by Ryan Hutton on Unsplash Sporades definition Webster's 1913 Edition has this funny little entry that defines sporades: >…
Zodiac Wavy Charts User Guide
Guy Ottewell's Zodiac Wavy Chart poster reveals secrets of the motions in the sky. Read this article to find out how to make the most of this unique object!
Your Eyeball Sun - Scale Model of the Solar System
What would happen if you shrank the Sun to the size of a human eyeball? Click and see.
The Moon Hat Customer Images
Moon Hat photos from customers and events. See the Moon Hat out in the wild — at trail runs, at home, and everywhere the Moon shines.
10 ways to wear a Moon Hat
Moon Finder, Phase Reminder, and Peeker. Wear the Moon Hat in 10 different styles with 1 bonus style. The Moon Hat gives you many ways to know the Moon
Feel the Earth spin
Why don't we feel the rotation of the Earth? The Earth is huge, humans are small. We get carried along for the ride! Read more, learn to feel the rotation.
How can I see Venus?
See the immense and majestic plane of the Solar System by learning to find Venus. Reveal the secrets of the sky and know how far you can see into space.
How many stars are in the sky? A Quiz
Have you ever wondered how many stars are in the sky? It's a simple question with a surprising answer! But first, let's try a quiz! How many stars exist?
Track the Sun
Track the Sun in the sky. Learn to do astronomy during the day! Step by step instructions for the Sun Tracker. What you need to begin tracking the Sun.
8 Ways to Find the North Star
Learn 8 ways to find the North Star in the sky - day or night. The North Star (Polaris) is a unique star in the northern skies. You can find it!
Where is the Sun?
Where is the Sun right now? It's where it always is - in space! The Sun doesn't move, we move. Here are 10 surprising things that block the Sun (cloud=#6).
Lights All Askew in the Heavens ... But Nobody Need Worry
Lights all askew... This hilariously-headlined New York Times article describes results of the experiment performed during the 1919 eclipse. The expedition proved Einstein's prediction. But the writer claims that only 12 men on Earth can really understand the result: that light's path is curved by space time.
Animal constellations in the night sky. How many are there?
Almost half of the official 88 constellations are animals! There are 42 animal constellations in the night sky. Here are the other types of constellations you will find in the celestial sphere. 42 animals, 28 objects, 14 humans, 2 chimeras (a mix of human and animal), and 2 natural features (a river and a mesa).
Japanese robot will land on the asteroid Ryugu
The Hayabusa2 spacecraft visits the Ryugu asteroid Update! June 24, 2018 - Haybusa2 has reached Ryuga. See this EarthSky.org article for more information. I…
Blue Moon, Dark Moon, Nose Moon, Tail Moon
The blue moon refers to the full moon phase. The fact that the entire moon phase cycle fits into a 30 or 31 day calendar month is unique. And, it's not just the full moon that can appear twice in one month. Any of the other major phases can appear twice in one calendar month. Read on to find out more!
Astronomy Koan
An astronomy koan is a short, easy-to-memorize phrase that distills a key teaching about astronomy. The words are simple enough for a child to learn, but they carry complex insights about scientific observations. Example: "Night is where you are."
Merry-Go-Round Earth shows Seasonal Constellations
To help us understand, we will build a physical model of the Sun as a campfire and a physical model of the Earth as a merry-go-round circling that campfire. In our Physical Astronomy model the campfire is the Sun and our bodies are the merry-go-round Earth. We will spin day after day on the daily merry-go-round.
Stellarium - Find the Humanity Star
A new satellite called the Humanity Star looks like a disco ball Update Apr. 1, 2018. _The Humanity Star is no longer an active satellite – it has fallen out…
Quiz - Can we see the Sun at midnight? Where is the Sun?
Can we see the Sun at midnight? Yes. We can see the Sun at midnight. But, only if we are at one of the polar regions during the Summer season. A quiz - seeing…
"Star In a Star" Translated into 90 languages
All of the articles about Physical Astronomy here at Star In A Star can be automatically translated. This amazing Google Translate widget lets you choose any language. Try it out!
Physical Astronomy - Definition of a New Way of Teaching
Physical Astronomy is a new way of teaching astronomy that emphasizes the human body and its relationship to other moving objects in space. The goal is to bring geometric and scientific awareness to a child's everyday sky observations. Kids learn easily visible sky motions at a "kid's eye level."
Moon Phase Emojis - A Review
Click to see moon emoji, moon phase emojis, space emojis, and astronomy emojis all collected together to copy paste. A review of all space emoji, pick your favorite.
See Mercury and Venus orbits during the day
If you could see the orbit of Venus would it fill the whole sky? The answer is no, it would fill only part of the sky. We learned a physical astronomy teachnique for how to see the orbits of the two inner planets Mercury and Venus.
Shapes with Shadows - astrosketching Moon features with Alex Massey
Our closest neighbour, the Moon, holds many secrets that lie in the shadows. As the Sun rises over the lunar horizon, it casts shadows that tell stories that are billions of years old. The lunar surface is a layered pattern - a palimpsest - that we can learn to interpret.
Galaxy Rise
Physical Astronomy by Daniel Cummings The Sun rises. The Moon rises. Stars rise. The Galaxy rises - twice. Each day the Earth rotates and sky objects (seem…
Super Moons
Super Moon The closest approach that the moon will make on its monthly orbit around the Earth coupled with a Full Moon. The December 3rd , 2017 Super Moon is…
Stellarium - See the Analemma
See the Analemma Stellarium can help you see sky patterns and practice Physical Astronomy. Video of the Analemma in Stellarium: By following this article you…
Walk to Mintaka
Physical Astronomy by Daniel Cummings As you walk toward the equator, Mintaka appears to rise higher in the sky. In this post we will learn how to use one…