Saturday: The Geminid meteor shower peaks tonight and tomorrow morning. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Gemini the twins. This point is about four fists held upright and at arm’s length above due east at midnight tonight. You can follow this point throughout the night, as it will remain near Gemini and the planet Jupiter. By 4:00 a.m., it is four fists above the southwestern horizon. This shower is typically one of the best ones of the year, producing bright, medium speed meteors with up to 80 meteors per hour under ideal conditions near the peak. This year, the moon will be in the waning crescent, leaving the sky dark enough to see the dimmer meteors.
Most meteor showers occur when the Earth passes through the
orbital trail of a comet. The broken off comet fragments collide with the Earth
and burn up in the atmosphere. Astronomers had searched for a comet source for
this shower since 1862 when the shower was first observed. Finally, in 1983,
astronomers discovered the object that created the fragments that cause this
meteor shower each year. To their surprise, it was a dark rock that looked like
an asteroid, not a shiny icy comet. Astronomers named this object Asteroid 3200
Phaethon. For more information about the Geminid shower, go to https://goo.gl/f4qMqg.
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 visualization tool called 100,000 Stars. It shows the stars in our
neighborhood in a very good 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: Mercury is a half a fist above the southeastern
horizon at 6:45 a.m.
Wednesday: 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 four fists above due
south at 6:00 p.m.
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 mid-September, the closest one yet,
passing just 3.8 million miles from the solar surface. It passed 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: The southernmost bright star visible in the northern
USA is one fist over the south-southwestern horizon at 7:00 p.m.
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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