Elsa Petersen's Science Methods II Blog

Lab:  Earth viewer Activity:  Earth and Moon formed ~4500 Mya The oldest minerals show evidence of liquid water on Earth (~4400 Mya) About 2.4 billion years ago, oxygen began to persist in the atmosphere. Before then, life did not necessitate oxygen.  Snowball earth -- earth was covered in ice (2200-2000 Mya)  Cambrian explosion (540 Mya) -- diversification of life First land plants: (470 Mya)  First land vertebrates (375 Mya)  Permian-Triassic Extinction (~251 Mya) referred to as "The Great Dying" or the largest extinction event in history Genus Homo (2 Mya)  Homosapiens appeared much later -- 0.2 Mya With young students, it is helpful to use a timeline to illustrate the concepts of earth's conception and beyond. With the students, it could be easiest to create a timeline that details the last billion years to be more specific with a smaller span of time. Pressbook:  - The first life on Earth was simple, prokaryotic bacteria. - At least three tim...

 Lab:  Today we discussed the planets in our solar system, creating a model of the four planets closest to the sun. Our task was to create a proportional model, discovering how small the planets are compared to the sun and how vast our galaxy is. We decided to make our model 60 meters long, with our sun at 350mm in diameter. At first, we made our sun way too small, meaning our planets were a fraction of a millimeter in diameter, which did not work for this particular model. With that information, we lengthened the distance of our model, and made the diameter of the sun much larger so that we could properly create our model.  Sun: 0m                                                                 Mercury: 14.5m                    ...