Planet X-treme Weather
Few places on Earth have perfect weather. We complain about the heat, the cold, the hurricanes and tornadoes, the rain and snow, or the drought. But compared to other places in our solar system, even Earth's worst weather is wimpy! Visit the Space Place at http://spaceplace.nasa.gov for a whirlwind tour of weather throughout the solar system. Find out about the hottest, coldest, windiest, and just plain weirdest planets and moons in our neighborhood. Click on "Amazing Facts" and "Planet X-treme Weather" to begin your tour.

Chomping Rocks on Mars
By Diane K. Fisher

Someday astronauts may go to Mars. One of their science chores may be to continue the work being done now by rover robots studying Mars rocks. Scientists want to know whatís in those rocks. They hold clues to the planetís mysterious past. To learn about the rocks, Mars astronauts will have to smash them and put the rock powder into an analyzer. The analyzer will detect what minerals are present.

But chopping those rocks into powder first will be a tough job. Whew!

But first, though, NASA is planning to send more robotic explorers to Mars. But how can robotic Mars landers or rovers break up rocks for an analyzer?

This is where NASAís special Planetary Instrument Definition and Development Program comes in. This program helped some NASA engineers to invent the needed Mars Rock Crusher. Only six inches tall, it can chew the hardest rocks into a powder.

The Mars Rock Crusher has two metal plates that work sort of like our jaws. One plate stays still, while the other plate moves. Rocks are dropped into the jaw between the two plates. As the movable plate moves in and out, rocks are crushed between the plates. The jaw opening is larger toward the top and smaller towards the bottom. So when larger rocks are crushed near the top, the pieces fall down into the narrower part of the jaw, where they are crushed again. This process repeats until the rock particles are small enough to fall through a slit where the two plates are closest.

Looking down on the jaws of the Mars Rock Crusher, we see a magnetite rock get crushed
into smaller and smaller particles.

Engineers have tested the Mars Rock Crusher with Earth rocks similar to those expected to be found on Mars. One kind of rock is hematite. The rusted iron in hematite and other rocks help give Mars its nickname ìThe Red Planet.î Another kind of rock is magnetite, so-called because it is magnetic! Rocks made by volcanoes are called basalts. Some of the volcanoes on Mars may have produced basalts with a lot of a mineral called olivine. We call those olivine basalts, and the Rock Crusher chews them up nicely too.

For a fun and interesting classroom activity and more about technologies to investigate other planets, visit The Space Place web site at http://spaceplace.nasa.gov/en/educators/QC_laser_spectrometer.pdf.