Martian memories and Pathfinder powerfinds

What we learned from the 'Little rover that could'

(CNN) -- Earthlings around the globe "oohed" and "aahed" as they witnessed the first up-close images from the Martian surface being beamed across their television sets and computer screens.

That Martian memory, from July 1997, may be forever imprinted in the minds of all who viewed the spectacular sights, and of all who followed the travels of Sojourner, which came to be known as "the little rover that could."

Pathfinder's main objective was to test technological advances, and to prove NASA could cost-effectively explore the universe in an era where costs are often considered paramount to science.

For NASA, Pathfinder proved to be a Martian gold find -- technologically and scientifically speaking.

Here's a look at some of Pathfinder's powerfinds:

As far back as the mid-1970s, when NASA's Viking missions went to Mars, scientists had believed a great flood once covered the planet's surface.

From its landing area, believed to be a former water channel, Pathfinder and its rover Sojourner beamed back sampling data and pictures of worn rocks and dune-shaped deposits that indicate the presence of sand. That, NASA said, is evidence that weather processes and flowing water helped create the surface of Mars.

The evidence, NASA said, points to a planet once Earth-like in its infancy.

It's difficult to see much when the Martian day begins, or so the Viking missions discovered.

But it would be two more decades before scientists would learn whether clouds or fog was obscuring that morning Martian view.

Pathfinder settled that debate: Clouds.

The mission also confirmed that dust is the primary absorber of solar radiation in the Martian atmosphere. That means the dust can interfere with the transport of solar energy.

How many times have you heard Mars referred to as "the red planet?"

Well, it's not.

The Viking missions first found evidence that our mysterious red planet wasn't so red after all. Pathfinder confirmed it.

So, if Mars isn't really red, what color IS it?

Try "butterscotch."

Pathfinder found wild temperature fluctuations on the Martian surface. It also gave NASA a different temperature profile of the planet than the one compiled from observations made by the Hubble Space Telescope.

So what would it feel like to stand on Mars at the start of a typical Martian day?

"In the morning your toes are comfy and your head would need a hat," said Pathfinder project scientist Matt Golombek.

Sojourner's journey onto the Martian surface capped the Pathfinder mission's ultimate goal.

Ninety percent of the mission focus was to prove a spacecraft could directly enter the Martian atmosphere, land on the planet's surface using airbags, bounce across that surface, and then deploy a rover.

Sojourner was the first semi-autonomous roving vehicle capable of conducting science experiments and taking pictures to be safely delivered onto the surface of another planet.

Remember that "monster pan" of the Pathfinder landing site? To date, that panoramic view, which took several days to assemble frame-by-frame, is the clearest picture of another planet that has ever been transmitted to Earth.

If you've ever driven a toy car by remote control, you know that first ride is bound to be a little bumpy, but it gets smoother as you get used to steering from afar.

NASA engineers had a similar experience with their minirover.

You may recall Sojourner had a little trouble getting off its rampway from the spacecraft (the airbags got in the way), and it got stuck on a rock or two while attempting to navigate the surface of Mars.

But the Pathfinder mission was a learning experience, and NASA says Sojourner's woes have already yielded dos-and-don'ts for engineers charged with designing similar rovers for future missions.

One future rover-must: Brushes to get dust off rocks.

Here's an odd find: Rock chemistry at the Pathfinder landing site may be different from the chemistry of Martian meteorites found on Earth.

Prior to Pathfinder, our knowledge of Martian rocks was limited to discoveries made from the Martian meteorites.

Using two-way ranging and Doppler tracking, NASA monitored Mars' rotation from Pathfinder's stationary position. The scientists wanted to get better measurements of the rate of change in Mars' spin axis.

Through these newer measurements, NASA will learn more about Mars' interior, and what lies at its heart: a solid or a liquid core.

Pathfinder's mission yielded 2.3 billion bits of Mars data; 8.5 million measurements of the planet's temperature and pressure; 16 chemical analyses of rocks and soil and surface materials; and 16,500 images.