This topography map illustrates where Phoenix is targeted to land, based on tracking as of midday May 24. The touchdown is most likely at the cross-shaped target at the center of the red ellipse and least likely to land at the ellipse's edges. The ellipse is positioned over the northern arctic plains of Mars, and is approximately 44 miles long. Credit: NASA/JPL-Caltech/University of Arizona

This is another map illustrating the landing zone. The area outlined in magenta reflects criteria being used to consider whether Phoenix engineers will perform another trajectory correction maneuver. If measurements taken later May 24 determine that the spacecraft is still on target to land within the magenta area, they will not correct its course. If the spacecraft is outside this region, its course will be corrected. In this map, green denotes safe-landing regions deemed to have few rocks through high-resolution imagery. Red represents unsafe, rocky territory. Credit: NASA/JPL-Caltech/University of Arizona

This map compares the size of the area where Phoenix is expected to land, called the landing ellipse (red), to the size of Long Island, N.Y. Phoenix has a 99.9 percent probability of landing within the area denoted by its landing ellipse, a region in the northern plains of Mars centered at approximately 68 degrees north latitude, 233 degrees east longitude. The ellipse is about 44 miles long. Credit: NASA/JPL-Caltech/University of Arizona

This map compares the size of the area where Phoenix is expected to land, called the landing ellipse (red), to the size of the San Francisco Bay Area. Phoenix has a 99.9 percent probability of landing within the area denoted by its landing ellipse, a region in the northern plains of Mars centered at approximately 68 degrees north latitude, 233 degrees east longitude. The ellipse is about 44 miles long. Credit: NASA/JPL-Caltech/University of Arizona