NASA/JPL
Solar System Ambassador
–-----
Contact
me at the email address at the bottom of this page to discuss
star parties and presentations for schools, scout groups, and
non-profit organizations.
–-----
That
being said, opinions expressed on this website are my own and not
that of NASA or JPL
Ephemeris
Radio
Schedule Monday - Friday
Ephemeris
air times (ET)
6:19
&
8:19* a.m.
- News
stations
*
New
time
7
a.m.-
Classical
stations
The
Stations of Interlochen Public Radio
Classical:
WIAA
88.7 FM Interlochen
94.7
FM Traverse City
WIAB
88.5 FM Mackinaw City
News:
WICA
91.5, FM Traverse City
WLNM
89.7 FM Manistee
WHBP
90.1 FM Harbor Springs, Petoskey
Observing
Weather in Northwestern Lower Michigan
- Clear
Sky Chart
from
Attilla Danko
-
NWS
Traverse
City Forecast.
-
Gaylord,
MI Weather Radar.
-
Satellite
Infrared Loop.
-
Canadian
based Infrared Satellite
(Michigan
shows best in the Eastern Canada view)
-
GOES-East
- Sector Views: Great Lakes - GeoColor
On this site
– articles of interest for this month
Ladies
of the Night
Ladies
of the Night II
The
Celestial River
O'Ryan
the Irish Constellation
The
Dog Nights of Winter
Auriga
the Charioteer
Taurus:
Bullish on Winter
Winter
Circle
Gemini:
The Twins?
VIN:
Very Important Nebulae
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February 2019
Interested
in learning more? If you live in northwestern lower Michigan
check out the Grand
Traverse Astronomical Society.
More
information on visible planetary and other events are available
on
Bob
Moler's Ephemeris Blog
the
day of the event. The blog contains Monday-Friday
program transcripts, most with illustrations and
additional information.
New
Links: I dug through the IPR web archives and found these:
I’m
interviewed about all things astronomical prior to the August 21,
2017 eclipse. Photo, text, and audio.
Extra!
My report on the Great American Eclipse.
New:
Added
animated
GIF of the sky at the totally eclipsed Sun, watching the shadow
pass over.
Highlights
for February
2019 (ET)
Date Local Event
Time
Feb 1 Fr Venus: 45.1° W
1 Fr 7:48 pm Moon South Dec.: 21.5° S
2 Sa 2:18 am Moon-Saturn: 0.7° S
3 Su 1:35 am Moon Descending Node
4 Mo 4:04 pm New Moon
5 Tu 4:26 am Moon Apogee: 406600 km
12 Tu 5:26 pm First Quarter
13 We 10:29 pm Moon-Aldebaran: 1.7° S
16 Sa 4:56 am Moon North Dec.: 21.6° N
17 Su 4:42 am Moon Ascending Node
17 Su 10:05 pm Moon-Beehive: 0.6° N
18 Mo 9:16 am Venus-Saturn: 1.1° N
19 Tu 4:06 am Moon Perigee: 356800 km
19 Tu 8:08 am Moon-Regulus: 2.4° S
19 Tu 10:53 am Full Moon
26 Tu 6:28 am Last Quarter
26 Tu 7:59 pm Mercury Greatest Eastern Elongation: 18.1°
27 We 9:17 am Moon-Jupiter: 2.5° S
Mar 1 Fr Venus: 40.8° W
NASA - SKYCAL - Sky
Events Calendar by Fred Espenak and Sumit Dutta (NASA's GSFC)
(with
occasional annotations and
additions)
The
Days of Our Seasons
The
Days of our Seasons
By
Bob Moler
Groundhog
day coming this month got me to thinking about the seasons and
those special seasonal days, like solstices, equinoxes and
cross-quarter days. February 2nd is a cross-quarter
day, supposedly when winter is half over. Below is a table I
created of the seasons for one year starting with last
December’s winter solstice.
I took the date
and times from
Astronomical
Tables of the Sun, Moon and Planets,
Third edition by Jean Meeus. TD
is Dynamical Time, used to calculate the positions of bodies in
the solar system, is currently about 68 seconds fast compared to
Universal Time (UT), which is tied to the Earth’s
rotation. The difference is slowly changing at less than a
second a year and doesn’t enter into the calculations.
The Julian Date is a consecutive date starting on January 1,
4713 BC at noon UT. It’s used by astronomers to calculate
date differences. like the length column in the table above
without worrying how many days months have or how many leap
years are in the interval. If you want to convert a calendar
date to a julian date or a julian date to calendar date go to
the Naval Observatory web page here:
https://aa.usno.navy.mil/data/docs/JulianDate.php.
Note
that the seasons are of different lengths. This is because the
Earth’s orbit is slightly elliptical. It reached
perihelion, its closest to the Sun, this year on January 3rd,
and it will reach aphelion, its farthest, on July 4th.
The Earth or any planet moves fastest when near perihelion.
And with perihelion 14 days into winter, makes winter the
shortest season. Autumn is the second shortest season 90 days
compared to winter’s 89 days. Summer at nearly 94 day’s
length is 4.7 days longer than winter. However we’re too
far north to really notice it. Spring is second with nearly a
93 day length.
The
rest of this article is based quite
a bit on the web
page: Common
Holidays in Relation to Equinoxes, Solstices & Cross-Quarter
Days – https://www.naic.edu/~gibson/cal/.
It’s
a cool list. Naic.edu
is the website of the Arecibo Observatory in Puerto Rico.
Apparently
it was someone’s (Gibson’s) personal post.
The
equinoxes and solstices are quarter days, for the four seasonal
quarters of the year. The table above has Mid-Season and Date
for the half way point in the season. The Cross-Quarter Days
column are the dates which are more or less celebrated down
throughout history.
The
first celebrated
cross-quarter day is
February 2nd,
Groundhog Day Which the famous weather prognosticating rodent in
Punxsutawney, PA forecasts the length of winter based on if he
sees his shadow. Supposedly,
if he sees his shadow winter will last for six more weeks, if he
doesn’t then spring is just around the corner. Actually
from February second to the vernal equinox is six and a half
weeks. If we had a winter like last year with a snowy April,
winter lasted until the second cross-quarter day. The
actual first cross-quarter day this year is February 4th.
February 2nd,
40 days after Christmas, is also celebrated as Candlemas Day,
when candles are blessed for the year, and the Feasts of the
Purification of the Virgin Mary and The Presentation of the
Child Jesus by the Catholic and
some other Christian churches.
The
first quarter day is the vernal equinox, which occurs in our
time zone on March 20th.
The Ides of March, the
15th
is pretty close to the vernal equinox and was the start of the
year for a time with the Romans. It was the date in 44 BC that
Julius Caesar was assassinated. March, named after the god Mars
was also for a long time the first month of the year. They, for
a time had 10 months, and consigned the winter months to ?.
Later they added two months in front of March, which is why our
9th
through 12th
months are named September (7), October (8), November (9) and
December (10).
The
second cross-quarter day to be celebrated is May 1st,
May Day. The actual 2nd
cross-quarter day this year is May 6th.
The
second quarter day, the summer solstice is on June 21st.
It’s near midsummer day, the 24th,
the feast of St. John the Baptist. It’s
a big deal in Europe. If you had a midsummer’s night
dream it would be on the night of June 23-24. Of course if that
date was really midsummer, summer would have to start in early
May.
The
third cross-quarter day is August 1st,
Lughnasadh. This is
Celtic. It was the wedding day of Lugh, their sun god with the
goddess of the Earth. This causes the crops to ripen in time to
harvest in the fall. The actual date this year is August 7th.
The
third quarter day is the autumnal equinox. This year it’s
on September 23rd.
The
fourth cross-quarter day is celebrated
on October 31st,
Halloween. It is the
day before All Saints Day, and Day of the Dead in Mexico. The
actual cross-quarter day this year is November 7th.
The
fourth quarter day is the winter solstice, December 21st.
This is in the midst of
festivals ancient and modern around the time the Sun starts
heading north again. Festivals of light, like Saturnalia, Yule,
Christmas, Hanukkah
There
you have the days of our seasons.
There
you have the days of our seasons.
|
Active Planetary Space Missions
We
have a new location for information on planetary space missions.
It's here at the Planetary
Society. The chart is created by Olaf Frohn, and is updated
every month.
Free
Software
Stellarium
is a fabulous
planetarium program with a very realistic sky and simple
controls.
They've
added some features in the latest version (0.18.2)
and
and a new rendering engine that may not be compatible with
computers more than a year or two old without
using command line options. See the Stellarium User Guide (pdf)
under Command Line Options for options to try. My older laptop
requires -a.
https://stellarium.org.
There’s
also a web based version of Stellarium. It’s pretty much
bare bones, but works much like the computer version. It’s
located here: https://stellarium-web.org.
Cartes
du Ciel
(Sky
Charts) is a great telescope companion. It
can be
downloaded
from http://astrosurf.com/astropc/.
Virtual
Moon Atlas
is
a great tool for reference at the telescope or desk.
http://www.astrosurf.com/avl/UK_index.html.
Celestia
is
a great 3D simulator of solar system objects and beyond.
http://www.shatters.net/celestia/
Hallo
Northern Sky
is
an interesting planetarium program. It seems
not
as polished as Stellarium, but has some cool features. I
use it when planning star parties
as a quick way to see what would be visible because
it loads quickly
http://hnsky.org/
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