Saturday: Since
Halloween is later this month; the stores are filled with bags of candy
clusters. Instead, take time to look at a star cluster. The Hyades cluster is
an open star cluster that represents the V-shaped face of Taurus the bull. It
is one of the biggest and nearest star clusters with about 200 stars 150 light
years away. The Hyades cluster was the first cluster to be the subject of
detailed motion studies. These studies allowed astronomers to pinpoint the distance
to the Hyades and provide important information about the scale of the
universe. Aldebaran, nearly two fists held upright and at arm’s length above
the east horizon at 11 p.m., is a foreground star and not a part of the Hyades
cluster.
Sunday: At
7 p.m., Saturn is one fist above the southwest horizon and Mars is one and a
half fists above the south-southwest horizon.
Monday: Along
with the not-so-subtle drug reference in their name, The Doobie Brothers made
an astronomy reference in their song lyrics: “Old black water, keep on rollin’,
Mississippi moon won’t you keep on shining on me.” Astronomers now think that
some of the water on Earth may be older than the Solar System. The chemical
signature of the water indicates it came from a very cold source, just a few
degrees above absolute zero. The early Solar System was much warmer than this
meaning the water came from a source outside the Solar System. For more
information about the old Earth water, go to http://goo.gl/QsEu5P.
Tuesday: The
Draconid meteor shower peaks for the next three nights. The meteors appear to
come from a point in the head of Draco, the dragon constellation. This point is
about five fists held upright and at arm’s above the northwest horizon at 10
p.m. tonight. This point remains near the trapezoid-shaped head of Draco
throughout the night. Typically, this is a minor shower. However, Draconid
meteors are slow moving which means you will have a easy time differentiating
true Draconid meteors, from Comet 21P/Giacobini-Zinner, from stray grains of
dust that happen to enter the Earth’s atmosphere near where we see the
constellation Draco. The moon will be out nearly the entire night so all but
the brightest meteors will be obscured. Luckily, tomorrow night brings its own
show. For everything you need to know about the Draconid meteor shower, go to http://goo.gl/HGkw0w.
Wednesday:
“Red Moon, you saw me sleeping alone. Before the Sun rises up. Before I turn on
my phone.” Early risers and late nighters will see a total lunar eclipse this
morning. During a total lunar eclipse, the Moon enters the earth’s shadow. Total
lunar eclipses are not as obvious as total solar eclipses because light still
reaches the Moon even when it is directly behind the Earth. That is because the
Earth’s atmosphere acts like a lens and bends rays of light that would normally
miss the Moon such that they hit the Moon. That doesn’t mean the Moon looks the
same during a total lunar eclipse as it does during a normal full Moon. Sunlight
is white. White light is the sum of all of the colors in the visible spectrum
(red, orange, yellow, green, blue, indigo and violet). Our atmosphere scatters
the blue component of the Sun’s white light. That is why our sky is blue. When
the Sun or Moon is near the horizon, the light passes through a lot of the
atmosphere meaning a lot of the blue light is scattered and the Sun or Moon
looks redder than when it is high in the sky. During a total lunar eclipse,
sunlight passes through a large slice of the Earth’s atmosphere. The remaining
light that reaches the Moon is reddish. Thus, the Moon looks red during a total
lunar eclipse. From our perspective in Washington, the Moon will start to enter
the Earth’s shadow at 2:15 a.m. Totality starts at 3:30 a.m. By 4:25 a.m., the
total eclipse will be over with the partial eclipse ending about an hour later.
For more information about this eclipse, and lunar eclipses in general, go to
the Science@NASA video at http://goo.gl/iCnkAu.
Thursday: Jupiter
is about four and a half fists above the east-southeast horizon at 6:30 a.m.
Friday: While
you are resting after looking for Draconid meteors for two nights, start
thinking about the Orionid meteor shower. This shower, which consists of the
earth colliding with pieces of the remains of Halley's Comet's tail, peaks on
the morning of October 21 but produces meteors from now until early November.
These meteors appear to come from a point in Orion, the hunter. This point is
about three fists above the southeast horizon at 1 a.m. tonight. You can follow
this point throughout the night as it will remain one fist above the prominent
reddish star Betelgeuse (pronounced Bet'-el-jews). The Orionid meteors are fast
- up to 40 miles per second.
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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