As members of a NASA scientific team investigating life on the planet Mars you have anxiously been awaiting data to be sent back from our latest probe to the Red Planet. The plan this time is to send an orbiting satellite that will take pictures of the Martian landscape and attempt to detect life forms through special sensing equipment on the solar panels and integrated with the orbitor's MOC camera.

This mission is similar to the earlier Viking missions that were launched on August 20th and September 9th of 1975. Crossing 400 million miles of space, a thousand times greater distance than from the earth to the moon, the trip took almost a year arriving in the summer of 1976. The mission was tied to the celebration of our 200 hundred year old democracy and represented probably the single greatest engineering project ever attempted by man.

Each Viking consisted of an orbiting satellite to photograph the Martian surface and a sophisticated lander that would sample the Martian soil. The Russians had tried 3 previous landers, but all of them had crashed on the surface. This mission owed a large part of its success to the fact that we photographed the surface from the orbiter and analyzed the photographs to determine the best landing sites before putting the lander down.

Viking I landed on July 20, 1976 in an area called Chryse Planita (Plain of Gold) at 11:53 AM Greenwich Mean Time. This landing was equivalent to firing a rifle in New York, and having the bullet strike a one foot target in Los Angeles.

We already knew many things about the planet because of astronomical observations done from telescopes here on earth. For instance, the Martian day is 24 hours and 37 minutes long. The seasons are similar to ours, but twice as long, and the Martian year is 687 days.

The lander took 3 dimensional pictures from its stereoscopic robot cameras. Temperature probes constantly monitored the planet's weather. The highest temperature measured was 70 degrees F. at the Martian equator. The average surface temperature on Mars is -15 degrees F. (Earth average is 75 degrees F.). The lowest Martian temperature at night near the South Pole was -275 deqrees F. (Earth -116 degrees F. recorded in the Antarctic).

The Martian atmosphere is only 1% as dense as the earth's. The atmospheric pressure is so low that liquid water cannot be sustained on the Martian Surface. There are polar ice caps that wax, and wane with the seasonal changes, but the water is sublimated from ice to vapor without passing through the liquid phase. This water vapor produces some wispy clouds in the sky and morning mists that arise as the temperatures increase during the day and melt the ice and frost.

There can be 200 mph winds that create massive sand storms that can blanket the planet and prevent astronomical observations from earth for months.

The Viking II lander came down near the North Pole of the Plain of Utopia on September 3rd, 1976. This was a site on the opposite side of the globe from Viking I. The Viking I's position would equate with the tropics on earth (Havana, Cuba.). The Viking II's position would equate with Newfoundland .

There was more water around the Viking II lander. Both sites recorded summer temperatures of about 30 degrees F., but winter temperatures varied with Viking I recording -10 degrees F. and Viking II -150 degrees F.. The terrain was similar around both sites.

Finally, Mars has a diameter that is half that of the earth's, but the land area is eqivalent to the earth's because of no oceans on Mars.