Round Top Lake gion15 Lost Keys Lake
Killer Sunset at The Sisters near Carson Pass Lake Tahoe to Mount Whitney: Crown Jewel of the Pacific Crest Trail Need a Map? Lost Al near Lost Keys Lake
Circular and crescent shadows from 2012 annular eclipse of the Sun.
Dicks Lake
Circular and crescent shadows cast during the 2012 Annular Eclipse of the Sun
Lake Aloha
Dicks, and Fontanillis Lakes from Dicks Pass

All Sky Constellation Star Chart

Star Chart
Study and Planning

Test Constellation Chart - Equatorial Region

Aloha Lake under Pyramid Peak from Dicks Pass
Field Use
Star Wheel/Chart
Star Wheel/chart

Backpacking Astronomy

Star Chart below

shows the whole Universe that's rotating through our planet's sky above each and every one of us, marked with the position of the Universe above us when it's Noon at Greenwich, UK, every single day of the year. All the stars and constellations represented on that chart below are rotating all the way around us each and every day of the year. What we actually see at night and what is overhead at Noon changes, a bit, every day of the year.

The Invisible World
Half of our "daily" view of the whole universe spinning around us every day is invisible, being "washed-out" by the daytime passage of the Sun, leaving only our nightly slice, our slice of our outward, "night-side," view of our Universe visible to observe. Our important questions are, "What slice of the night will we see at Night during our backpacking trip? What "slice" of the Universe will be washed out during the day?"

These questions are practically and esthetically important.

This page will answer those questions.

Universe @ Noon

The dates along the curving line undulating across the center of the All-Star Chart below correspond with the point in the sky above Planet Earth at 12 noon at Greenwich, UK, on that particular date. Our positions in the Sierra are roughly 8 hours West of Greenwich. Classic star charts show us exactly what we cannot see in the sky during the day.
What's overhead at midnight of any particular date is not quite exactly six months different than the "Sun" dates on the chart below.

That's why I've included the Digital Star Wheel below.

It's adjustable to your current location, date, and time:


The Star Wheel


This celestial information will be more important the further out into Nature that we hike, as the deepening darkness of wilderness opens up the depths of night skies to our experience. I want to know exactly what I am seeing, and why.

More Information
The Universe, our Galaxy


Our planet-wide destruction of dark night skies (we neglect nothing) diminishes and disappears the deeper we push into wilderness, finally revealing the full depth of Time and Space around us. These observable expanses bring up questions in my mind, such as what time is it, really, in terms of exactly where our planet is pointed in our Galaxy and Universe during Day and Night?

We've already used astronomical intformation to figure out basic local Noon and backpacker timekeeping. Now we want to put our daily Night and Day observations into a bigger "annual time" context, withing the physical reality of our own galaxy and the greater universe beyond.

As I mentioned above, we can find exactly where we are pointed in the Universe THROUGH THE SUN at 12 Noon every Day on the Star Chart featured on this page below, and find the exact position our Earth is pointed at, in the Universe at Midnight, here on our Digital Star Wheel:

The Star Wheel


Set the TIME feature to Noon (and check "show daylight") to determine what part of our Stellar Universe is washed out by the Sun at the midpoint of day during daylight hours.
Setting the TIME to Midnight shows us the what part of the universe is visible directly above us, which centers what's visible between Sunset and rise.

Identify those positions on the whole year star chart below, and you will know what is passing overhead at Noon during the day, and be able to identify the seasonal constellations bracketing Midnight. Let's go to the next step, and figure out the main stars too.

Fire up the digital star wheel. Click the show "Alt/AZ grid" checkbox, then bring your cursor to the center of the circle in the middle of the Sky at Noon and at Midnight. Our goal is to determine Noon and Midnight's respective Right Ascension Times. These coordinates read-out on the upper-right of the page. Note them.


Big Context
Match these "RA Times" with those positions on the Star Chart below to see exactly what's straight overhead at Noon and Midnight, which puts the rest of the night and daytime skies into context, and puts our seasonal slices of Time into the biggest context.

Yup, that's it, and all there is. Our whole Universe spins around us every day.

Midnight and Noon define exactly what perspective we are going to have on the universe spinning around us every day and night of the year. Despite the fact that it takes a whole year's worth of nightly (and daily) observations to view the totallity of our surrounding universe (twice?), which, all together makes one (two?) full circle(s) around us each and every day.


The whole universe spins around us twice a year. Once visibly, at night, the other invisibly, during the day.

Center Point
The center point of our physical celestial map below is anchored in time by the position of the Sun in the Sky at 12 Noon on the Vernal Equinox (March 20) in Greenwich, England, as measured on the sine wave (wiki) of the Earth's elipictic on the map below.

The Elipictic
This elipictical undulating line across the center of the map below marks out the effect of the Earth's off-axis tilt during one orbit around the Sun. It represent where we are. "pointing," so to speak.
Sometimes the Earth is pointed "up,"along this "line," other times "down." Our celestial "start point" of the year is the Vernal Equinox, which is the point in time when the tilting plane of the Earth is flat, halfway between its up and down rise and fall along itst elipictic path.

Can you see what I'm saying?
If not, you can actually look at it:

Watch Elipictic in MOTION
(APOD Video)

This is Representational, rather than Real:

Motion of the Sun Simulator


more simulators
observational information

Empire Time
The Sun position dates across the Elipictic on the chart below reflect Noon at Greenwhich, and must be adjusted for your local Noon. Thus the utility of the "In the Sky" star wheel for ascertaining local times.

History of Time with Standards & References

Keeping Personal Time
In addition to ascertaining stellar and constellation positions at Noon and Midnight, we can measure the daily movement of Sun and the stars at night from our local reference points since we know that the sky rotates 15 degrees for each hour that passes. Again, our whole map rotates once a day.
This predictable stellar motion happens because one 24 hour day equals one 360 degree daily rotation of the Whole Earth. Our 24h x 15d movement for each hour equals a 360 degree circle. That means that we can figure out where the stars will be on any day at any time we choose since they rotate 15 degrees per hour from our local Noon and Midnight reference points. And...

15 degrees is the width of every typical human hand!
How about that?


A "hand" is not just an ancient Egyptian measure of horse heights (hands) , but a span of celestial Time, too.


These relationships between Time, Space, our physical position, and the width of our hand means that we can use the workings of Nature Itself as references in Time and Space along the length of our backpacking trip, making Nature itself our fundamental field clock and compass. We backpackers are the "crazy hands" on Nature's Clock, and the "spinning needle" in Nature's Compass. Using astronomical timings requires we look up and record some fundamental astronomical information to bring on our trip.

Using the Sun and Stars as our Clock and Compass


Natural Timekeeping may sound complex now, but it quickly becomes "first Nature" with a little use and practice. It's the stupid watches and GPS that are unnatural. We were made to be Reflective of Reality.

Backpacking Navigation Context and Goals

All Astro & Terrain Mapping Tools


Noon and Midnight
will be almost exactly 12 hours apart.
Almost 12hr because this perfect daily rotation of Earth is lengthened by its moving one day along its orbital path around the Sun as well as one Earth "rotation" on its axis. Two motions affect the length of Earth's days. The length of the Earth's daily spin is affected, slightly lengthened, by its motion along its annual orbit around the Sun. This motion along our orbital path as we spin creates a difference between Sidereal Time, or our "orbital time" vs. Solar Time, which would be our "rotational," or daily "spinning" time.

Sidereal and Solar Time Simulator


The whole universe spins around us every day, though we only see around half of it, more or less, depending on what time of year it is, and if we are lucky enough to have dark skies and good eyes. Hitting the trail is going to improve our nighttime visibility, which requires some study to make the most of the fundamental beauty and knowledge watching the operation of our Universe brings.

We will study the digital sky wheel linked to above. We will take note of, and become familiar with the key stars and constellations before we depart. We will print out a paper Sky Map for Field Use. We will note Sun rise, noon, and set times & bearings in our "Trail Journal & Land Alamanac" so that we can tell time and find directions using the fundamental workings of Nature.

"Ground" Work

Navigation Tools


Our Science News Section

Looking into the Mirror of Life

All Sky Constellation and Star Chart

All Sky Constellation Chart with RA & DEC to set our Digital Sky Telescopes



Celestial Resources

Sky Mapping


Locate Various Features
Constellation Map Above
in our

Our Galaxy Links

Deep Space Links


Motion in the Sky

Seasons of the Zodiac


Rotating Sky


Sun Motion


Seasons, Ecliptic, and the Sun

Map Name
Test Constellation Chart - Equatorial Region

Compass Offset









Backpacking permitting authority

National Forest

Wilderness Area

Physical location


Full Annular Eclipse
Banner Image

Annular eclipses cast circular shadows.
Annular Eclipse of the Sun

(Camera Reading)
Sun, 20 May 2012
06:47:57 PM

Elevations   More Information


The current "Elevation," or "Size," of the Universe appears to be Aprox. 14 billion Light Years from "Top to Bottom" and "Edge to Edge:"

The Big Unit

Or, What I call,

Tahoe-Whitney Celestial Resources


USNO Celestial Data Resources


Space & Science News

Map Credit

Sky Publishing

Sky & Telescope
The Essential Guide to Astronomy

Buy it Here
Test Constellation Chart - Equatorial Region
By The Editors of Sky & Telescope

Charts from the Classroom Resources of Earth & Sky

This Constellation Chart is
also Found in the Public Domain

WSU.EDU, chart 1

WSU.EDU, chart 2


Alex Wierbinski

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Lake Tahoe to Mount Whitney

Your guide to backpacking the Sierra Crest, including the Tahoe to Yosemite, Pacific Crest, and John Muir Trails

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© Lake Tahoe to Mount Whitney: Crown Jewel of the Pacific Crest Trail