Date Entered: 22 November 1989 (by R. Greeley)
Date Last Revised: March 1991
Site area is a rather smooth plain with Amazonian volcanic unit with locally fresh lava flows and a large area of aeolian materials. Northern lowland plains; covers principally the Amazonian-age Arcadia Formation (lava flows, small cinder cones; terrain modified by aeolian periglacial processes). Toward the east merges with volcanics from Alba Patera.
Units: Aa1, Aa5; Arcadia Formation (young volcanic material)
Sequence of lava flows; in places, mantled by aeolian and periglacial material.
Character of surface: Rolling and knobby plain surface, complicated in places by curved, concentric low ridges and small domes; dunelike features occur locally.
Rock abundance: mostly 8 - 14%, in places 1 - 7% and >14% (Christensen model).
According to topographic and engineering constraints, landing sites at north latitudes (higher than 40 deg. N is better) and at elevations less than 0 km are proposed. All sites have been chosen for safety considerations (pressure constraints, low surface roughness).
Obtain composition of grooved, knobby, and mottled members of Vastitas Borealis Formation, and volcanic materials of Arcadia Formation. Landing in this site would provide accessibility to various volcanic units (Amazonian to Hesperian).
For small rover: to determine the elemental composition of the surface and subsurface samples of martian soil; to determine organic compounds, and free and bound volatiles in martian soil; to obtain high-resolution color stereo images of the martian surface; to study the frost zone depth, to study meteorological parameters; to study dust storm dynamics.
For balloon: to determine the mineralogical and elementary composition of martian soil; to study detailed structure of surface; to study structure and dynamics of atmosphere, especially through the boundary layer; to study meteorological parameters and to make navigational measurements; to study subsurface structure; to study structure of the magnetic field.
HNu, Aa2, Aa5: rather poor; Aa3, Aa4, Aps: rather good.
Estimated Traverse Distance
First balloon would be injected October, 1995 at Ls 170 deg. to 175 deg. ; second balloon would be injected 2 to 4 weeks later.