Courtesy of EarthSky
A Clear Voice for Science
In North America, the slender waning crescent moon and brilliant planet Jupiter shine side by side before sunrise tomorrow. At mid-northern latitudes, the moon and Jupiter rise a bit more than one hour before the sun. From far northern Canada and Alaska, you might not see the moon and Jupiter at all, because these worlds rise at nearly the same time as sunrise that far north.
It’s a different story for the more southerly latitudes, like in South America. In that part of the world, the moon and Jupiter won’t be side by side as they are here in North America. At equatorial South American latitudes, the moon and Jupiter will rise about 1.5 hours before the sun. At far southern South American latitudes, the moon and Jupiter will rise about 2 hours before sunrise. The farther south you live, the earlier these morning worlds rise before the sun.
The waning crescent moon and Jupiter rise sooner before the sun in the southern hemisphere because it’s autumn in that part of the world. On autumn mornings, the ecliptic – the pathway of the moon and planets – is highly tilted to the horizon. Therefore, the waning crescent moon and Jupiter rise a maximum amount of time before the sun because April is an autumn month in the southern hemisphere.
Here in the northern hemisphere, it’s the opposite season: spring. On springtime mornings, the pathway of the moon and planets hits the horizon at a shallow angle. Therefore, the waning crescent moon and Jupiter rise a minimal amount of time before sunrise tomorrow because April is a springtime month for our northern hemisphere.
Written by Bruce McClure