Ancient Mars’ weather report: Continued cold and dry
Landscape features rule out warm or wet scenarios
HOT AND COLD Mars had a chilly youth, new research suggests, with much of the planet’s water locked away in high-altitude glaciers, as pictured in this artist’s illustration (right), though the ice was less extensive than shown here. Geologic evidence on the planet doesn’t match up with previous proposals of a warm, wet world (left).
R. Wordsworth