Mostly Saturn With A Chance Of Auroras

About 8° separate Saturn and the waning gibbous moon tomorrow morning (April 17). This map shows the view about an hour before sunrise, but the two will be visible from 2 a.m. onward. Antares in Scorpius the Scorpion also joins the scene two fists to the right of Saturn. Created with Stellarium

Do we have any bread bakers out there? Runners? Tomorrow morning, assuming clear weather, they (and anyone else inclined) will see the waning gibbous moon and Saturn stand together in the southern sky an hour or two before sunrise. Both are in the Teapot constellation, Sagittarius the Archer. Sagittarius and neighboring Scorpius are summertime groups doing a pre-show for early risers. To see them at nightfall, we’ll have to wait till June and July.

This simulation shows the moon’s appearance tomorrow morning. I’ve also marked the terminator and a few prominent craters. The bottom or southern half of the moon will display hundreds of craters of all sizes. Credit: Virtual Moon Atlas with additions by the author

A small telescope will show Saturn’s rings and its brightest moon, Titan, which tomorrow morning will shine a little more than four ring-widths to the right or west of the planet. That same telescope will show many spectacular craters along the curve of the moon’s terminator. During its waning phases, the terminator is the advancing line of lunar sunset. An astronaut standing on the terminator would see the sun hovering at the western horizon, its low, grazing light illuminating every hillock, crater rim, bump and peak in stark relief against their long shadows.

The sun photographed earlier today by NASA’s Solar Dynamics Observatory. Not a sunspot in sight! Credit: NASA

There’s also a chance for northern and southern lights late this evening into tomorrow with a minor G1 storm predicted from about 1-4 a.m. CDT  Monday morning. If you’re up late, give a look north for signs of a greenish arc or maybe even a few faint pillars of light. After some recent sunspot activity, the sun’s gone quiet again. Today it’s completely blank.