Natural History Events in the Methow
May-
May 17-
Scientific insight indicates that life on earth is improbable. For example, if our sun and solar system were located just inside one of the spiral arms of the Milky Way galaxy instead of just outside, there would be far more space debris crashing into the earth, making life here difficult to impossible. The sun itself has grown 25% more radiant (hotter) over the 4.5 billion years of the earth's existence, but temperatures on earth have stayed within the range acceptable to life, due to fortuitous changes in the atmosphere, like a large reduction in the amount of carbon dioxide, which traps solar energy. This carbon dioxide has been sequestered as carbonate rock and fossilized organic matter.
Both the 23.5° tilt of the earth's axis and the moon are apparently the result of a massive collision with a Mars-size planet just as the earth was forming. This impact knocked the earth off its original 90° axis orientation to the sun, and ejected enough solid material into space to form the moon. Without the earth's tilt there would be no seasons, and without the moon there would be no tides, both of which have greatly enhanced the diversity of life. The gravitational drag of the moon has also slowed the rotation of the earth, which originally had a 8 hour daily rotation, which would have created winds on the earth's surface to great for larger life forms.
The earth is unusual in having large amounts of both rock and water at its surface, which would not exist in they way that they do except for plate tectonics. A smaller planet would not retain heat in its core the way the earth does; it is this heat that drives plate activity and mountain building. A larger planet with the same mineral context of the earth would form too thick a crust for tectonic activity to occur. Hydrogen and oxygen have also been released from the mantle over time due to the activity of plate tectonics, forming water in the atmosphere, which then falls as rain. Oxygen in the upper atmosphere formed ozone (which is O3), which has just the right structure to block high energy cosmic radiation from reaching the earth, which would have made terrestrial life impossible. Oxygen accumulated in the atmosphere over time, but fortunately it ceased to accumulate when it reached 20% concentration; any higher and fires would burn living plant material as well as dead.
Goldilocks would be quite at home here: everything is just right.
Both the 23.5° tilt of the earth's axis and the moon are apparently the result of a massive collision with a Mars-
Goldilocks would be quite at home here: everything is just right.
Pollen grains from several plant species magnified 1000x. The universe seems to revel in beauty.
The Methow Naturalist is a voice for nature, and a window into the intricate natural world of the Methow Valley in north-central Washington, the Cascade
Mountains, and the into the larger bio-geo-chemical web of the living Earth..
Good Planets are Hard to Find
