1. Exploring Meteorite Mysteries Crater Hunters
Extracted from NASA Document NASA EG HQ
Public Domain
For use with More Lessons from the Sky “Impact Craters”
[This slide set was adapted from the slide set for NASA’s Exploring Meteorite Mysteries. This version was designed especially for use with “Impact Craters-Part 4” published in More Lessons from the Sky, a monthly lesson plan offering in the Satellite Educators Association on-line Newsletter and archived in the SEA Lesson Plan Library available at ]
[Photo credits are listed in the notes for each slide.]
Impact Craters – Part 4 (Lesson 7: “Crater Hunters” – Where do they come from?)
One of the key things we’ve learned from space exploration is that craters are among the most important geologic features in our solar system. Almost everywhere spacecraft have traveled they have sent back pictures of craters.
Focusing on cratering, discuss how the imaes of Mercury, Venus, Moon and Mars are similar and how they are different.
Satellite Educators Association More Lessons from the Sky

2. 26. The Moon
The Moon is covered with craters in a wide range of sizes. You can see a few of the largest with your naked eyes, and many more with binoculars.
(NASA JSC photo AS )

3. 27. Mercury
The planet Mercury, as seen by the Mariner 10 spacecraft, is also covered with craters. Mercury has essentially no atmosphere, and its cratered surface looks much like that of the Moon.
(Photomosaic, NASA Jet Propulsion Laboratory)

4. 28. Venus
The surface of Venus has craters too. Venus has a thick atmosphere which destroys many impacting bodies before they reach the surface. Some do make it through, though, to form craters. The largest crater in this picture is 60 km across. We cannot see the surface of Venus directly, since the atmosphere is filled with thick clouds. This picture was made from radar data, taken by the Magellan spacecraft. Radar images have no color. The colors in this picture were made by a computer, to make it easier to pick out the craters and other features.
(Photomosaic, NASA Jet Propulsion Laboratory)

5. 29. Mars
Impact craters are also visible on the planet Mars. The thin Martian atmosphere does not do much to slow an impacting body from space.
(Photomosaic, U. S. Geological Survey)

6. 30. Mars crater
This photo, taken by the Viking spacecraft, shows a relatively fresh crater on the Martian northern plains. If craters are so common in the solar system, why are they so rare on Earth?
(NASA Jet Propulsion Laboratory)

7. Pause here. Pause here. Students should pause here to discuss:
The similarities and differences of the surfaces of each planet pictured above. Focus on cratering.
Then proceed to the next slide of the Barringer Crater (“Meteor Crater”) near Winslow, Arizona.

8. 6. Meteor Crater, Arizona
The freshest impact scar on Earth, Meteor Crater in Arizona, is only 50,000 years old. Earlier in its history our planet suffered many large impacts.
(NASA JSC photo S )
Ask, “Where are the craters on Earth?” Discuss.

9. Stop here.
Stop here.
Learners complete the production of their world maps of some impact crater sites on Earth.

10. This is a screenshot of a completed map from ArcGIS Explorer Online
This is a screenshot of a completed map from ArcGIS Explorer Online. Notice the impact sites are marked with spherical symbols that are graduated and colored according to diameter.
Sources: Esri, DeLorme, NAVTEQ, TomTom, Intermap, Increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), and the GIS User Community
If learners are not using computers, you may choose to use an overhead projection transparency of a blackline world map. The blackline master can be found in the Teaching Notes for this lesson.
Review and discuss the world map while learner groups continue to view their own maps in order to insure each group’s map is on target.
If needed, review answers to Questions 1-4 on Where Are the Craters on Earth answer sheet.
Discuss the general terrain as seen in the maps. Include in the discussion reference to any information about impact craters encountered in this lesson so far, including the modeling experiments from Part 3.
After inspecting the world maps, learners write descriptions of three specific impact craters (Spider Crater, Manicouagan, and Clearwater Lakes) by completing the middle two columns on Impact Crater Descriptions worksheet.
ONLY AFTER the completion of the middle two columns of the worksheet, continue with the rest of these slides. Viewing the images of these impact crater on Earth here and completion of the Further Analysis of the map using ArcGIS Explorer Online should provide learners with enough new information to allow them to write revised descriptions into the third column of the worksheet in the same way scientists revise their own theories based on new information.

11. Stop here.

12. 32. Clearwater Lakes, Canada
The craters of some impacts can still be seen, often as round lakes like the twin Clearwater Lakes in Canada. These two craters, 32 and 22 km across, are both 290 million years old.
(NASA JSC photo 61A-35-86)

13. 33. Manicouagan, Canada
Manicouagan crater in Canada is a ring-shaped lake nearly 70 km across. In the 212 million years since it was formed, the crater has been deeply eroded.
(NASA JSC photo S )

14. 34. Spider Crater, Australia
Some craters have been almost completely eroded away. Spider Crater in Australia, 13 km across, is over 600 million years old. It is barely recognizable as an impact structure.
(NASA JSC photo S )

15. Stop here.
Stop here.
If using computers, learners are to complete the Further Analysis section of Using ArcGIS Explorer Online tutorial at this time.
Discuss

16. Earth (replacement for Slide 31)
The Earth has suffered many impacts over its history, just like the other planets. However, Earth’s surface is constantly being changed by erosion. Water, ice, wind, and plate tectonics have destroyed most of the craters that Earth once had. Only relatively young or quite large craters exist on Earth today.
[Credit: NASA Goddard Space Flight Center Image by Reto Stöckli (land surface, shallow water, clouds). Enhancements by Robert Simmon (ocean color, compositing, 3D globes, animation). Data and technical support: MODIS Land Group; MODIS Science Data Support Team; MODIS Atmosphere Group; MODIS Ocean Group Additional data: USGS EROS Data Center (topography); USGS Terrestrial Remote Sensing Flagstaff Field Center (Antarctica); Defense Meteorological Satellite Program (city lights). Retrieved from on January 21, 2013.]
This slide brings closure to Part 4 Activity A provides and introduction point for Activity B.