---
type: source
title: "Mars Lava Tube + Ice Co-location Correction: Elysium Mons (24-29°N) and Ice-Rich Amazonis Planitia (39-41°N) Are NOT Proximate"
author: "Luzzi et al. (JGR:Planets 2025), IOPscience 2025 Elysium Mons skylight study, Nature Communications 2025 marsquake brine study"
url: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JE008724
date: 2026-05-03
domain: space-development
secondary_domains: []
format: article
status: unprocessed
priority: high
tags: [mars-settlement, lava-tubes, water-ice, isru, elysium-mons, amazonis-planitia, radiation-shielding, geography, site-selection]
intake_tier: research-task
---

## Content

**CORRECTION OF 2026-05-02 SESSION FINDING:**

The May 2, 2026 research session concluded that Elysium Mons (western flank, ~24°N) was "potentially the best co-location site" for Mars settlement because its western flank "faces Amazonis Planitia" where Luzzi et al. (2025) found near-surface ice at "tens of centimeters depth." This conclusion was geographically incorrect: the two features are NOT proximate.

**Geographic reality:**

1. **Elysium Mons** is located at approximately 24.8°N, 147°E (summit). The western flank skylight (IOPscience 2025, confirmed via HiRISE images ESP_042629_2090_RED and ESP_063477_2090_RED) is at approximately 24-29°N.

2. **Luzzi et al. (2025) Amazonis Planitia ice candidate sites**: AP-1 (39.8°N, 202.1°E), AP-8 (40.75°N, 201.3°E), and AP-9 (40.02°N, 203.35°E). These sites are in NORTHERN Amazonis Planitia, at the boundary with Arcadia Planitia — approximately 39-41°N.

3. **Latitude gap**: The Elysium Mons skylight (~24-29°N) and the shallow ice sites (39-41°N) are separated by approximately 10-15 degrees of latitude, or roughly 600-1000 km. These are NOT co-located.

4. **Near-surface brine zone** (Nature Communications 2025, marsquake seismicity analysis): Confined to >30°N. Elysium Mons at ~24-29°N is SOUTH of this zone entirely.

**What the Amazonis Planitia section near Elysium Mons has**: The southern portion of Amazonis Planitia (near Elysium Mons) does not have the documented shallow ice (tens of cm depth). The near-surface ice documented in Luzzi 2025 is in the NORTHERN portion, near Arcadia Planitia (~40°N). At 24-29°N, ice exists but is buried at greater depths.

**Elysium Mons skylight status**: The skylight is confirmed via optical (HiRISE constant shadow depth, elliptical structure) and thermal imaging (heat retention indicating subsurface connectivity). However, SHARAD radar has NOT confirmed a subsurface void at this specific location — it has confirmed buried lava flows in the broader Elysium region, which is a weaker form of evidence.

**Implication for Mars settlement**: The Elysium Mons skylight (radiation protection) and the Amazonis Planitia shallow ice (ISRU water) require two separate infrastructure sites separated by ~600-1000 km. This reintroduces the "dual-site bootstrapping problem" that the May 2 session thought was resolved.

**Key context from related sources:**
- Luzzi et al. (2025): ~9,000 thermal contraction polygons mapped; ice at tens of cm depth at AP-1/AP-8/AP-9; confirmed as candidate human landing sites by NASA
- IOPscience 2025 (Elysium Mons PCC): First comprehensive analysis of the western flank skylight using CTX + HiRISE + THEMIS thermal data; "constant shadowed region" confirms access to subsurface environment
- Nature Comms 2025 brine study: Seasonal marsquakes confined to >30°N; implies ice-to-brine phase transitions at meter-scale depths in northern hemisphere

## Agent Notes
**Why this matters:** This corrects a May 2 KB error and significantly weakens the "Elysium Mons as best co-location site" claim. The bootstrapping problem for Mars settlement (radiation + water + power + manufacturing) is more complicated than the May 2 session characterized. Settlement infrastructure cannot solve radiation (lava tube at Elysium Mons at 24°N) and water ISRU (shallow ice at 40°N) from a single site.

**What surprised me:** The candidate ice landing sites in northern Amazonis Planitia (AP-1, AP-8, AP-9) are at ~40°N — solidly within the brine-active zone (>30°N). The entire ice-accessible terrain that was being discussed as proximate to Elysium Mons is actually ~15 degrees of latitude away. The May 2 session was misled by the geographic naming ("Amazonis Planitia faces Elysium") without checking the specific latitude.

**What I expected but didn't find:** Confirmation that the Elysium Mons western flank PCC is close to any documented near-surface ice deposit. No such evidence found at ~24-29°N.

**KB connections:**
- Session 2026-05-02 "lava tube co-location" finding — this corrects it
- [[water is the strategic keystone resource of the cislunar economy because it simultaneously serves as propellant life support radiation shielding and thermal management]] — same logic applies to Mars settlement water ISRU
- The self-sustaining space operations threshold (three loops: power, water, manufacturing) — water loop access at Mars now requires either deeper drilling at the Elysium Mons site OR a geographically separate water ISRU site

**Extraction hints:** Two potential claims:
1. "The confirmed lava tube skylight on Elysium Mons' western flank (~24-29°N) and the shallow ice deposits (tens of cm depth) in northern Amazonis Planitia (39-41°N) are separated by ~600-1000 km, making single-site co-location of Mars radiation shielding and shallow water ISRU implausible at the Elysium Mons location — the dual-infrastructure bootstrapping problem persists"
2. "SHARAD radar has not directly confirmed a subsurface lava tube void at the Elysium Mons western flank skylight; the 2025 IOPscience study used thermal and optical methods (heat retention, constant shadow) to infer subsurface connectivity — stronger than morphology alone but weaker than direct radar detection"

**Context:** The broader debate is about where the first permanent Mars settlement should be sited. The Elysium Mons skylight was appealing because it seemed to solve both radiation AND water in one place. This correction suggests it only solves radiation. Alba Mons at 40.47°N may be the genuine co-location candidate (see separate archive).

## Curator Notes (structured handoff for extractor)
PRIMARY CONNECTION: `agents/astra/musings/research-2026-05-02.md` — corrects the "best co-location site" conclusion from that session
WHY ARCHIVED: Corrects a geographic error in May 2 research. The co-location of Elysium Mons skylight and Amazonis Planitia ice was assumed, not verified by latitude data. This matters for all KB claims about Mars settlement site selection.
EXTRACTION HINT: The extractor should focus on the latitude gap (24-29°N vs. 39-41°N) as the specific geographic disconfirmation. Do NOT extract the "Elysium Mons as co-location site" claim without this correction. Consider whether the Alba Mons alternative (separate archive) should be the primary settlement candidate claim.
