Chasing Daylight North: A June Park Road Trip

Four Parks in Ten Days

1In late June, eighth grader Leilani Ferraro and her family drove north through four national parks, from a desert park in west Texas to a glacier park in Montana. The family covered about 2,800 km in ten days, camping most nights. Leilani kept a trip log for her science class. At each stop she used a sky app to record the length of the day and how high the Sun climbed at noon, measured in degrees above the horizon. Near the end of June these values change by only a minute or two from one day to the next, so she could compare the stops fairly.

2Leilani also texted with her pen pal, Tomás, who lives in Santiago, Chile, south of the equator. He sent her the same two numbers for his city. While Leilani was hiking in shorts, Tomás wrote that it was a cold, gray winter week with early sunsets.

3Back home, her teacher, Mr. Rashid Okonjo, set up a model. A lamp stood in the middle of a table to stand for the Sun. A student carried a globe in a circle around the lamp to show one year. The globe's axis was tilted about 23.5° and always pointed toward the same wall of the room, the way Earth's axis always points toward the same place in space, near the North Star. The class stopped the globe at four places around the lamp and taped small paper flags at different latitudes to see how long each place stayed in the light as the globe turned once.

4Every clear night of the trip, Leilani also sketched the Moon. On June 18 she saw a thin crescent low in the west just after sunset. On June 21 the Moon was half lit, on its right side, high in the south at sunset. On June 25 more than half of it was lit. On June 28 a full moon rose in the east just as the Sun set in the west.

5At the last campsite, a park ranger mentioned that a total solar eclipse would happen the next year. She said it would be total only along a path about 150 km wide, while people far from that path would see a partial eclipse or nothing at all.