Moon Phases and Eclipses . In Texas, teachers are expected to teach the phases of the Moon, both as an example of an observable pattern of change in the sky (2nd through 4th grades), and as a part of understanding the nature and orbit of the Earth-Moon system (5th grade and up).
Solar wind speed: 470.2 km/sec density: 5.4 protons/cm3 more data: ACE, DSCOVR Updated: Today at 2127 UT. A minor stream of solar wind flowing from this small coronal hole could reach Earth on Dec. UPDATE: How do you make noctilucent clouds appear?