Pictures From Mars

The Phoenix Mars Lander, which thrilled NASA scientists when it landed safely over the weekend, has sent back amazing images of never-before-seen terrain taken during its first full day of exploration. During its three-month mission on Mars, the lander will search for signs that liquid water existed on the planet's northern plains and look for traces of organic compounds in the soil, trying to determine whether it could have supported primitive life. —Heather Wax