mars yuk yung 3-14-05. earth: 13,000 km diameter 150 million km from sun 365 days in year 24 hours...
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MarsYuk Yung3-14-05
Earth: • 13,000 km diameter• 150 million km from sun• 365 days in year• 24 hours in day• -88 deg C to +58 deg C temp range• 1000 mb surface pressure• 78% nitrogen, 21% oxygen
Mars: • 7,000 km diameter• 1.5 AU from sun• 687 Earth-day year• 24 hour, 37 minute sol (Mars day)• -127 deg C to 17 deg C temp range• 7 mb surface pressure• 95% carbon dioxide atmosphere
Number Density (cm-3)
Alt
itud
e (K
m)
Candor Chasma,Valles Marineris MGS PhotographQaidam Basin, China SRTM Shaded Relief
Mars MGS photograph; 43.2°N Lat, 90.6°W Long, in Tempe Terra
Afar Triangle, Ethiopia SRTM Shaded Relief
Martian Crater on Elysium Planitia MGS Photograph
Bosumtwi Crater, Ghana, Africa SRTM shaded relief
Gusev Crater, MarsCerro Armazones, Chile
Meridiani PlanumSan Gabriel Mountains
MSG MOC Image of “delta”system within Holden Crater on Mars (Malin et al, Science 2003)
Lena Delta in Siberia (NASA Scientific Data Purchase/Landsat 7)
A Brief History of ALH84001• 4.5 Gy ago: Igneous rock (orthopyroxenite)
which accumulated in a magma chamber on Mars. Oldest known rock from ANY planet!
• From 4.5 – 4.0 Gy: Suffered several shocks, probably from asteroid or comet impacts, formed mm-thick, cataclastic “granular bands” at high temperature.
• ~4.0 Gy ago: Major shock event brecciated it, rotated fragments, but did not heat it.
A Brief History of ALH84001, cont’d
• ~4.0 Gy ago: Carbonate blebs formed in cracks by low-T precipitation events. (Aqueous, followed by at least 1 shock.)
• 15 Myr ago: Blasted off of Mars into space by another impact
• ~11,000 years ago: After wandering through space, landed on Antarctic Ice sheet.
• ~500 years ago, exposed at surface in Allan Hills.
Was this Martian ever alive??!!
So what do the magnetite crystals in ALH84001 actually look like?
(Thomas-Keprta K.L., Bazylinski D.A., Kirschvink J.L., Clemett S.J., McKay D.S., Wentworth S.J., Vali H., Gibson E.K., Jr., and Romanek, C.S. Elongated Prismatic Magnetite Crystals in ALH84001
Carbonate Globules: Potential Martian Magnetofossils. Geochimica Cosmochimica Acta 64 (23), 4049-4081, 2000)
€
N2++e→ N+N
O2++e→ O+O
E(0) = 2.5 ev or 7km/s
Acknowledgements
• NASA
• NSF
• JPL
• Diane Michelangeli
• Chris Parkinson
• Yung’s Caltech Research group