The winter season begins on Wednesday with the December solstice, which is when the sun reaches its southernmost position among the stars.
On that day the sun will rise as far south in the southeast as it will all year, travel across the sky on its lowest path for us in the northern hemisphere (those in the hemisphere will see the sun take its highest path) and then set as far south in the southwest as it will all year.
Because the sun’s rays strike our part of the Earth (in the northern hemisphere) at the weakest angle, it is the weakest sunlight flux of the entire year. The sun is also above the horizon for the shortest duration of the December solstice, so this day marks the lowest cooking power and cooking time for us. There is still some residual heat from the warmer summer, so our coldest days will likely be a bit later in the winter.
Tips for buying a telescope
This is probably the busiest shopping time of the year and that includes buying telescopes. One of the chapters in my online Astronomy Notes textbook is about telescopes – types of telescopes, powers and limitations of telescopes, and the effects of the atmosphere on light from distant objects.
I end the chapter with some advice on buying a telescope for yourself or a loved one, then I give pointers to review sites that will go into the finer details of a particular telescope that caught your eye. Warning.
There are three things you need to consider when buying a telescope. The first is the quality of the optics, specifically the “objective”, which is the large mirror at the back of the telescope for a reflector telescope or the large glass lens at the front of the telescope for a refractor telescope. .
The lens is what determines the two most important powers of a telescope: light-gathering power and resolving power. Magnification is the least important power of a telescope and this power can be changed with a different eyepiece.
Second, the stability and sturdiness of the frame. You don’t want the telescope to wobble when you touch it, and the wobble is more noticeable under higher magnification.
Last but not least, it’s easy to transport the telescope and set it up when you’re in the field. A hard-to-install telescope quickly loses its charm and tends to stay tucked away in the closet or garage. Visit astronomynotes.com/telescop to learn more about telescopes.
In fact, another telescope tip is to get to know the helpful folks at the Kern Astronomical Society, our local astronomy club. Choose their brains at a public party or bring your telescope to one of the club parties. They enjoy sharing the night sky with others. Visit kernastro.org for more details on KAS.
In the night sky
On the night of the solstice (December 21), Mercury will be at its greatest separation from the sun in our evening sky. After that, it will start moving closer to the sun and it will be between us and the sun on January 7th. Venus rises slowly away from the sun.
On Christmas Eve, Venus, Mercury and a very thin crescent moon will form a beautiful low triangle in the southwest. The whole triangle is a little too big to fit in the binoculars’ field of view, but you’ll be able to get two items at once.
A much larger crescent moon will be near Jupiter on December 28. Also, on this night, Mercury and Venus will pass each other, coming within a thumbs width of each other.
A week later, on January 3, the waxing gibbous moon will be next to Mars in Taurus. Slightly darker than in mid-December, Mars is still one of the brightest points in the sky.
Good start to the program
The Orion capsule of the Artemis-1 crashed on December 11 on schedule. This was a very good start for the Artemis program which will culminate in people landing in the south pole region of the moon where there is evidence of water ice deposits in the perpetual shadow of the crater walls. This should happen in 2025.
This mission was an unmanned test of all equipment, so he took a more leisurely pace to the moon and back. Cameras on the solar panels and inside the capsule gave us a view of what astronauts will see on future missions.
The Artemis-2 mission with four astronauts on board will take just four days to travel from low Earth orbit to the moon in the spring of 2024. Artemis-2 will be a test of anything but an actual moon landing. The landing will take place with Artemis-3.
Look forward
Bakersfield College is closed for the next two weeks. The William M. Thomas Planetarium capped off a successful fall show schedule with a sold-out screening of “Season of Light,” which has become a holiday tradition for at least several families. The spring schedule will be posted in mid-January on the planetarium website bakersfieldcollege.edu/planetarium.
I wish you a happy new year 2023!
