# At moonrise the eastern slab's shadow marks the moon's minor and major standstills on the large spiral, and…

> Disputed: At moonrise the eastern slab's shadow marks the moon's minor and major standstills on the large spiral, and the site was used to follow the…

Source: https://mysteriesdept.com/mysteries/chaco-canyon/answers/ANS0D9KVMYY1XT5/at-moonrise-the-eastern-slabs-shadow-marks-the-moons-minor  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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[Questions](https://mysteriesdept.com/questions)[Great houses of Chaco Canyon](https://mysteriesdept.com/mysteries/chaco-canyon)[Does the Sun Dagger also mark the 18.6-year lunar standstill cycle?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KV4KG0K3Y/does-the-sun-dagger-also-mark-the-18-6-year-lunar-standstill)Answer

Answer · Great houses of Chaco Canyon

# At moonrise the eastern slab's shadow marks the moon's minor and major standstills on the large spiral, and…

At moonrise the eastern slab's shadow marks the moon's minor and major standstills on the large spiral, and the site was used to follow the 18.6-year cycle.

**Disputed** Answers **1** questionPublished0

## Where it stands

**Disputed** Two pieces of evidence for, two against. It needs two reviews to be accepted.

## What it predicts

- The shadow edge falls on distinctive points of the spiral only at the standstills.
- Chacoan building or ceremony is timed to standstill years.

## What would rule it out

- Shadow-edge positions at the standstills shown to be no more distinctive than those on other dates.

## Evidence 2 for · 2 against

[At sunrise at declination +18.4°, standing in for the moon at its northern minor standstill, the eastern…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVN6R48Z3/at-sunrise-at-declination-18-4-standing-in-for-the-moon-at)

Supported

FOR

[In November 1987, at the major standstill, the project photographed the moonrise shadow of the eastern slab…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVNEJ69MJ/in-november-1987-at-the-major-standstill-the-project)

Supported

FOR

[One spiral designed to mark three or four separate dates is very unlikely; the extra dates are most likely…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVNY65NF6/one-spiral-designed-to-mark-three-or-four-separate-dates-is)

Suggestive

AGAINST

[There is no ethnographic evidence that historic Pueblos attended to the lunar standstill cycle.](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVNPC5WM5/there-is-no-ethnographic-evidence-that-historic-pueblos)

Suggestive

AGAINST

## The questions it answers

[Does the Sun Dagger also mark the 18.6-year lunar standstill cycle?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KV4KG0K3Y/does-the-sun-dagger-also-mark-the-18-6-year-lunar-standstill)

Part of [Was the Fajada Butte spiral made and used as a solar calendar?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KV4BP04RM/was-the-fajada-butte-spiral-made-and-used-as-a-solar)

Most likelyThe lunar shadow positions are by-products of the slabs' shape; the site was not used to follow the…

## Cite it

```
Mysteries Department. (2026). At moonrise the eastern slab's shadow marks the moon's minor and major standstills on the large spiral, and… [Answer ANS0D9KVMYY1XT5]. https://mysteriesdept.com/r/ANS0D9KVMYY1XT5
```

Key

**ANS** 0D9KVMYY1XT5

Kind

Answer · hypothesis

Origin

Published

Version

1

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