Exploration of Martian Lava Tubes

Christoph Brendel and Janko Trisic

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Introduction

Study about the Lava Tubes on Mars

Can they provide shelter for humans in the future?

Source: Wikipedia2

Objectives

Define the main criteria for the lava tubes:

● Over 100 m wide

● Close to ancient ocean

● Possibility to contain water: find out if they contain H2

O ice, separate those who have it

from the rest

Find the tubes that meet the requirements

Find out if they can provide shelter for humans

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The Lava Tubes

Skylights and rilles

Way bigger than the ones on Earth Source: Wikipedia

Source: http://blogs.esa.int/caves/2015/05/06/caves-the-hidden-side-of-planets/ Red line represents 50mSource: Google Images.

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Ancient ocean

“Oceanus Borealis”

Still a hypothesis, but with many features that

back it up:

● Shorelines

● Flow lines

● Clay sediments

● Cross bedding

4.1-3.8 Billion years ago

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Location

Many volcanoes on Mars

Areas with the highest rates of lava tubes: Tharsis and Elysium

Tharsis has plenty volcanoes but is far away from theoretical shore

Elysium is in the middle of hypothetical ocean

Source: Google Earth 6

Elysium Mons

Good location

Rootless cones

Lava tubes

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Lava tubes locations

Elysium Mons

Olympus Mons

Arsia Mons

Pavonis Mons

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Rootless cones

http://www.dronestagr.am/pseudocraters-in-myvatn-lake-iceland/9

B. C. Bruno / Spatial Analysis of Rootless Cone Groups on Iceland and Mars 10

Criteria

Skylights:

Optical imaging

● Diameter of 80-200 m● Hole in the surface● Shadows within the circle

Lava tubes:

GPR

● Hyperbolas in cross section and continuous lines on longitudinal section

Gravimetry

● Gravimetric anomalies

Rootless cones:

Optical imaging

● Diameter between 0.5 km and 1.5 km

● No central mountain in the crater

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Optical imaging

Minimum resolution Available resolution

Skylights 30 m/pixel 0.3 m/pixel

Collapsed Tubes

30 m/pixel 0.3 m/pixel

Rootless Cones 15 m/pixel 0.3 m/pixel

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Optical imaging

Lava tube southeast of Elysium Mons, approx 130m in diameter

150 m

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Nasa/JPL/University of Arizona / https://www.uahirise.org/ESP_035098_2065

Elysium Mons

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500 m

d = 1 km

d = 0.7 km

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If we analyzed a scan that was cutting

the tube, we would see the hyperbola

from figure A.

If we were to scan along the tube, we

would see a constant, horizontal line

A: hyperbola marking a cavity

B: Ice layer C: water layer

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Gravity anomaly

C. Rowell / Geophysical analysis of structures and flow geometry of the Blue Dragon lava flow

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MethodsFrom Earth:

● Analysis of previous imaging and GPR data

From orbiter:

- SHARAD - 20 MHz

- MARSIS - between 1,8 and 5 MHz

- HiRISE images - resolution of 0.3 m/pixel

- Spectrometer (CRISM)

From Orbit:

● Radar sounding (GPR)

● Gravity anomaly

On site:

● Lander: GPR and gravimetric tools

● Helicopter 3D modeling 18

Methods

Currently available methodsMethods that could be provided

in the next few yearsMethods that need more

research and better technology

High resolution imaging from Mars orbit 3D modeling with a helicopter Robotic exploration the cavesShallow and ground penetrating radar on orbiter Human exploration of caves

Spectrometer on orbiter

Tracing of gases

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25 MHz 5 MHz 0.5 MHz

Material v in m/ns λ depending on frequencyvacuum 0.3 12 60 600fresh water 0.034 1.36 6.8 68basalt 0.11 4.4 22 220clay 0.15 6 30 300granite 0.13 5.2 26 260ice 0.16 6.4 32 320limestone 0.13 5.2 26 260permafrost 0.15 6 30 300sand 0.15 6 30 300volcanic ash 0.09 3.6 18 180

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3D modeling of lava tubes

● JPL Mars Helicopter Scout will be on board of the Mars 2020 mission

● If the helicopter is a success, 3D modeling of the entrances will be available

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Exploration with robots

● Getting the robot into the cave is very challenging

● Data transfer from within the cave is limited

○ Ceiling very thick

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Exploration with robots

R. Whittaker / Technologies for Exploring Skylights, Lava Tubes and Caves - NASA 23

Conclusion

Detection of lava tubes is already possible

Modeling of the entrances is possible in the near future

Entering the caves is still a huge obstacle

High importance for humanity if we intend to colonize Mars

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