Saturday: Jupiter is less than a fist held out at arm’s length to the right of the nearly full moon in the eastern sky at 7:00 p.m. They will stay in this same orientation throughout the evening and into the late-night sky.
Sunday: Are you disappointed because you are not going
anywhere for the holidays? Why not take a (virtual) trip to outer space using
Google’s new visualization tool called 100,000 Stars. It shows the stars in our
neighborhood in an accurate 3-D simulation. The Sun is initially at the center.
If you zoom in, you can click on neighboring stars and learn more about them.
Go to http://stars.chromeexperiments.com/
for the simulation. It works best on a Chrome browser.
Monday: One of those stars in our neighborhood, the bright
star Sirius, is one and a half fists above due southeast at 10:00 p.m.
Tuesday: Today is the start of the Saturnalia celebration,
an ancient Roman festival in honor of their god Saturn, the god of agriculture
and time. The holiday featured a break from work and school, a public banquet,
and private gift giving. Some of these customs influenced the secular aspects
of Christmas celebrations. For example, after Sheldon hugged Penny on The Big
Bang Theory, Leonard proclaimed, “It’s a Saturnalia miracle” https://youtu.be/yarNJnZw2yk. It would
not be a miracle if you saw the planet Saturn today. It is three fists above
the south-southwestern horizon at 6:30 p.m. The very bright planet Venus is one
fist above due southwest at this time.
Wednesday: Mars is right below the moon, three fists above
due east at 10:00 p.m. As the hours go by, the moon will move slightly eastward
compared to Mars, making it look like Mars is moving past it in the race from
east to west. This is a great night to see how the moon appears to move
slightly differently across the sky compared to planets.
Thursday: With the Sun as low as it gets in the
Northern Hemisphere winter sky this weekend, you may wish it was a little more
prominent. Every orbit, NASA’s Parker Solar Probe has a close encounter with
the Sun. Its last close encounter was in early October. Its next close
encounter will be the closest one yet, passing just 3.8 million miles from the
solar surface on Christmas Eve. It will pass through the boundary between outer
space and the region where the Sun’s magnetic field has a tight hold on the plasma
that makes up the outer layer of the Sun. Since the Sun does not have a solid
surface, this is as close to touching the Sun as an object can get. It is
analogous to “touching” a cloud. The cloud does not have a definite surface but
there is a boundary between “cloud” and “not cloud”. For more about the mission
plus short videos, go to http://parkersolarprobe.jhuapl.edu/.
Friday: Wow. The moon gets around. Now it is by the bright
star Regulus at 10:00 p.m. Regulus is just to the right of the moon, one fist
above the east-northeastern horizon. Like Mars and the moon on Wednesday,
tonight you can see how the moon appears to move compared to planets. Spoiler
alert: stars and planets appear to move very similar to each other compared to
the moon’s apparent motion. This is because the moon is so much closer to the
Earth than stars and even than relative neighbor planets such as Mars.
The positional information in this column about stars and
planets is typically accurate for the entire week. For up-to-date information
about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.
All times are Pacific Time unless noted.
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