December 4, 2022
Sunday, December 4, 2022
Nick Strobel
Bakersfield College is now in the week of final exams. This Thursday, December 8, will be the last show of the fall season at the William M Thomas Planetarium: the popular holiday show “Season of Light”.
The Artemis-1 mission has worked very well after a successful launch late at night on November 15. On November 28, the Orion spacecraft reached its farthest distance from Earth of 268,563 miles, making it the farthest distance that any spacecraft capable of carrying humans has gone. Orion has been sending back beautiful images of Earth, reminiscent of the last time we got images from a human-rated spacecraft 50 years ago with the Apollo 17 mission. Fifty years! At its farthest distance, Orion was about 40,000 miles from the moon, so the images we saw showed a small moon just slightly bigger than a small Earth. Because Earth reflects so much sunlight, the camera's exposure settings have to be greatly reduced, so the much dimmer stars are invisible. Our small blue marble home world was seen against an immense inky-black space.
The Orion capsule will return to Earth on December 11, splashing down in the Pacific Ocean off the San Diego coast. The Orion spacecraft has performed so flawlessly that the mission team added additional tests to the schedule and much of the team was able to enjoy a few days off for Thanksgiving.
The Artemis 2 mission will have a four-person crew on board, who will run the Orion spacecraft through its paces for 10.5 days sometime in spring 2024. They'll get tantalizingly close to the moon but they'll leave the landing to the Artemis 3 crew in 2025. More definitive timeframes and the actual crews for Artemis 2 and 3 will be determined only after Orion splashes down next week.
The outer planets, Mars, Jupiter, and Saturn are already up above the horizon at sunset. Orange-red Mars is now brighter than any true star in the night sky. It is next to one of Taurus' horns. About midway between Mars and the waxing gibbous moon is the Pleiades star cluster at the shoulder of Taurus. Tonight, the moon will be just above the head of Cetus. On December 7, the full moon will occult Mars (pass in front of Mars, so it covers up Mars) from 6:32 PM to 7:32 PM The night of December 7 is also when Mars will be at opposition, directly opposite the sun. Because of Mars' elliptical orbit, Mars was actually closer to us on the night of November 31 at just 50.6 million miles. As we pass close to Mars, it appears to move backwards among the stars over the past several and future several weeks. It'll start moving forward again in the middle of January.
Jupiter blazes away among the dim stars of Pisces below the Great Square of Pegasus. The Juno spacecraft orbiting Jupiter continues to send us back spectacular pictures and wonderful data about the interior structure of Jupiter. Earlier this fall Juno had a close approach of Jupiter's moon, Europa. Europa is slightly smaller than our moon and is the target of NASA's next mission to the outer solar system because it has a deep ocean of liquid saltwater underneath a thin icy surface. That ocean is possibly a great environment for life, so Europa is probably the best place to look for current life beyond Earth (Mars might have had life long ago). The Europa Clipper mission will launch in October 2024 and begin orbiting Jupiter in April 2030 in paths that will take it by Europa 45 to 50 times during its prime mission of four years. Hopefully, the Europa Clipper will be as hardy as Juno and other planetary missions, so it will get several mission extensions.
The star chart above is the view at 8 PM showing where Mars and Jupiter will be. Out of the frame further right in the southwest will be Saturn at the tail end of Capricornus. The constellation Orion is now easily seen rising in the east by 8 PM Its entourage of Canis Major with very bright Sirius and Canis Minor with bright Procyon will be visible by about 9:30 PM
The night of December 13/14 is the peak of the Geminid meteor shower that always puts on a good show with more meteors per hour than the other major meteor showers of the year. On an ideal night with a very dark sky, the Geminids produce up to 100 meteors per hour! This year won't be ideal but still quite fine. The waning gibbous moon will rise at around 10 PM, so the evening hours before then is the best time to observe the meteors. The next night, the moon rises later and the meteor shower will still be going strong.
I hope to see some of you on December 8 for the Season of Light show!
—
Nick Strobel
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com
