Online at the Live From Mars site under Featured Events, you can find a brief description of how Pathfinder collected weather data on Mars. That description also provides links to more extensive information on NASA/JPL's own Pathfinder project pages and the University of Washington's LIVE FROM EARTH AND MARS project. (Not affiliated with WEATHER WORLDS, but a great source of current Mars weather data!)

The challenge for students was to figure out what key weather measurements they thought were most important to gather here on Earth, and then how to obtain them, by designing, building and/or acquiring instruments to collect these data.

As part of this process, students also had to figure out protocols or procedures about how and when to gather data. For example, is it enough to gather temperatures just at noon? Do you also need night-time lows? If you want maximum and minimum temperatures, how should you go about securing these? As another example: Pathfinder's temperature sensors were set at three different heights above the Martian surface because researchers knew there were great differences caused by just a few centimeters (yes, centimeters!) change in elevation. Would such measurements be relevant on Earth?

But students were not limited just to instruments paralleling those actually on Pathfinder. There's no rain gauge on the spacecraft, but rainfall is an important part of Earth's weather. Students were encouraged to start from scratch and come up with their best ideas. Temperature, wind, pressure, humidity, hours of daylight, cloud cover-- these were all areas that students considered.

There was a cost limit to keep everyone's ambitions in check: all the instruments together must not cost more than $100. Students were not expected to buy the instruments, but instead, borrow or make them. In addition, there was no size limitation: kids could suggest and build large anemometers and wind vanes. The challenge was more to figure out how to monitor weather on Earth, rather than deal with size constraints appropriate for launching an instrument pack to another planet.

After initial debate in class, students were invited to go online with their suggestions, comments and brainstorms. Veteran PTK teachers consider the online debate a key aspect of these collaborations. To focus the task, teachers submitted only one plan per class. The process of formulating that plan -- by in-class debate, posting online and responding to other postings and by more internal discussion -- was made into a rewarding activity for the students no matter whether the teacher posted the final results to the list, or also left that to students.

Each class that submitted a plan received focused feedback from three other classes in more or less the same grade level, as well as more general comment from the entire list.

There were elementary (3-5), middle (6-8) and high school (9+) categories. This provided transcontinental feedback to focus attention and lend significance to their activities. Based on the feedback and monitoring, the wider debate students came up with a final plan.

In this second phase of the activity, classes built their own WEATHER WORLDS, using either the consensus plan developed during Phase 1, or whatever other data sets they could access (local weathercasts or news reports), but they were responsible for doing so on a daily basis and assuring the data's accuracy. Their internal verification plans were part of the information they provided when signing up.

Classes filed their daily reports in a standardized format. The specific types of data that a class chose to collect was discussed online during Phase 1, and classes were able to access this archive to aide in making their decision.

For example, a younger class might have chosen to do temperature readings at three heights every day. An older class could have chosen to collect a comprehensive set of temperature, wind speed, air pressure and cloud-cover measurements.

The raw data were mounted on the WEATHER WORLDS site in a way that made it easy to capture or download for Phase 2. It was also displayed in a graphic format, just like the student-generated cloud patterns seen on the Live From the Hubble Space Telescope site.

While the data were being collected, WEATHER WORLDS hosted an online discussion of possible ways to analyze the accumulating data. Once more, NASA experts made some suggestions, referring to Pathfinder and Earth-orbiting weather satellites, but students themselves had the final say.

During the Live From Mars broadcast, "Today on Mars," some of the classes that had collected data and already begun work on their analysis were be featured.

Final WEATHER WORLDS reports were posted on the web site. Classes that submitted daily data received online recognition. All classes that submitted a full analysis of their weather data received a certificate of participation from NASA.

The idea behind WEATHER WORLDS was to give students the feel of real world science. Not only did they gather data in ways parallel to what Pathfinder did on Mars, they also used the Internet to debate plans with their peers, something that NASA scientists also have to do.