We are knocking on warm weather’s door, although all Ohioans know that it always snows at least once in April. This week the daytime temperatures will be in the 50s and 60s while the nighttime temperatures will dip into the 30s and 40s. Sunset is right around 7:40 PM (mostly thanks to daylight saving time effectively making the sunset an hour later). All of the astronomical objects should be visible no more than an hour later. The forecast indicates some clear nights as well as partially clear and rainy nights – the full spectrum of cloud coverage. During those clear nights be on the lookout for the full moon, an early-morning planetary triangle, some pre-spring galaxies, and during the day watch the sun during the spring equinox.

Friday, March 18, marks the full moon for the month of March. Both Thursday and Friday the moon will appear “full”. Thursday night the moon will be 99.8% illuminated and Friday night the moon will be 99.1% illuminated. So anything in the eastern sky after sunset will be washed out from the moon’s glow. Catching the full or nearly-full moon just after sunset is a great time to try out some landscape/astrophotography. Imaging the moon next to common objects (like houses) will make the moon seem gigantic! You can even experiment with using a telephoto lens to produce the optical illusion of having an even larger moon.

If you are an early riser and find yourself up before sunrise peer low in the eastern skies between 6:20 AM and 7:20 AM. You will spot a planetary trio. Venus and Mars will be next to each other, separated by only 5° . Then, closer to the horizon will be Saturn. Despite appearing to be neighbors in the sky, there is a physical separation between these planets of tens, or (in the case of Saturn) hundreds, of millions of miles. All three of these objects are incredible targets through binoculars or a telescope. The grand ring system of Saturn, the phase of Venus, and the red color of Mars can all be easily spotted.

Mars, Venus and Saturn still form a trio in the morning sky.

Spring is typically referred to as “galaxy season” by many amateur astronomers and astrophotographers. This is because at this time of year we are looking up and out of the galactic plane. If we were looking through the galactic plane (like in the summer), our line of sight would be clouded with nebulae and dusty regions of our Milky Way galaxy (which still make for incredible observing targets). By looking out of our galaxy, we can see thousands of distant galaxies spanning from a few million light-years away to over 50 million light-years away. The image shown is just an example of all the galaxies in the eastern sky that can be seen with a decently powerful telescope – it is way too crowded to read in some spots! Using a camera attached to your telescope to take long exposures will certainly help you spot fainter and more distant galaxies.

Some of the very many galaxies visible in the spring sky as plotted in the astronomical software, Stellarium. There are many, many more.

Sunday, March 20, marks the spring equinox. Not only does this officially start astronomical spring, but it has some interesting implications about the path the sun takes through the sky. If you follow the sun through the day on Sunday, it will trace out the celestial equator. The celestial equator is just a projection of the earth’s equator onto the sky. So the sun will be directly over the earth’s equator and will give an equally long day and night.

The equinox marks the point in time that the center of the sun crosses the celestial equator.

Despite the warm daytime temperatures, the nighttime temperatures are still on the cold side. Be prepared to do some astronomical observing this week during the completely or partially cloudy nights. Get outside and explore the cosmos with a telescope or binoculars and discover the thousands of stars, nebulae, and galaxies that are “frozen” in time in our night sky. Be on the lookout specifically this week for the full moon, a planetary meetup, thousands of galaxies, and trace earth’s equator by following the sun on the day of the equinox.

Clear Skies!

Jared May: What's Up, March 14 - 21