Saturday: The CWU Physics
Department and the College of the Sciences is hosting its monthly First
Saturday planetarium show today from noon to 1 p.m. CWU physics graduate and
future science teacher Jessica Kisner will give a show about the winter sky.
The nights are long and the sky is (sometimes) crisp and clear. So you ought to
know what you are looking at. The show is free and open to all ages. There will
be a show at noon on the first Saturday of every month of the school year
hosted by different CWU astronomers and astronomy educators. The CWU Lydig
Planetarium is room 101 in Science Phase II, just off the corner of 11th and
Wildcat Way, H-11 on the campus map found at https://www.cwu.edu/facility/campus-map.
Sunday: If the Sun looks
big today, your eyes are not playing tricks on you. The Earth was at perihelion
a little before midnight last night, Pacific Standard Time. If you dig out your
Greek language textbook, you’ll see that peri- means “in close proximity” and
helios means “Sun”. So, perihelion is when an object is closest to the Sun in
its orbit, about 1.5 million miles closer than its average distance of 93
million miles. Since it is winter in the Northern Hemisphere now, the seasonal
temperature changes must not be caused by the Earth getting farther from and
closer to the Sun. Otherwise, we’d have summer when the Earth is closest to the
Sun. The seasons are caused by the angle of the sunlight hitting the Earth. In
the winter, sunlight hits the Earth at a very low angle, an angle far from
perpendicular or straight up and down. This means that a given “bundle” of
sunlight is spread out over a large area and does not warm the surface as much
as the same bundle in the summer. For the Northern Hemisphere, that very low
angle occurs in December, January and February.
Monday: The Moon makes a
triangle with the open star clusters called the Pleiades and the Hyades
throughout the night. At 6:00 p.m., the Moon is above the east-southeastern
horizon. The Hyades cluster is about a fist to the lower left of the Moon and
the Pleiades is about a fist to the upper left of the Moon. By 4:00 a.m., they
are nearly in line with each other just above the west-northwestern horizon.
Tuesday: Do you look into a
nursery and say, “it’s a boy” or “it’s a girl”? Not me. I say, “It’s a star”.
Of course, I like looking into a stellar nursery – a star-forming region such
as the Orion Nebula in the middle of Orion’s sword holder. The Orion Nebula
looks like a fuzzy patch to the naked eye. Binoculars reveal a nebula, or
region of gas and dust, that is 30 light years across. The center of the nebula
contains four hot “baby” stars called the Trapezium. These hot stars emit the
ultraviolet radiation that causes the Nebula’s gas to glow. The Orion Nebula is
nearly four fists above due south at 10:30 p.m.
Wednesday: Venus is one and
a half fists above due southwest at 5:30 p.m.
Thursday: Just over a year
ago, the NASA probe called New Horizons sent back the first detailed images of
Arrokoth, also called 2014 MU69, a Kuiper Belt object that formed in its
current state about 4.5 billion years ago. Arrokoth looks like a 30-kilometer
long reddish snowman spinning through space. Check out the newest images and
the latest information at http://pluto.jhuapl.edu/. Arokoth means “sky” in the Powhatan/Algonquian
language. Astronomers first nicknamed the object “Ultima Thule”, meaning a
place beyond the known world. But Nazis and Neo-Nazis had co-opted that term
long ago, leading to the official, much more meaningful name. Arrokoth is red,
just like Mars. You can’t see Arrokoth in the sky. But you can see Mars at 6:30
a.m., one and a half fists above the southeastern horizon.
Friday: Tonight’s Full Moon
is called the Full Wolf Moon since wolves tend to howl more often in the cold
winter nights.
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.
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