To the reader:
The Skywatcher's Diary for January 2000 has been prepared by Robert C.
Victor. Credit to the author and to Abrams Planetarium,
Department of Physics and Astronomy at Michigan
State University, and mention of our Sky
Calendar, would be appreciated.
A sample issue of the Sky Calendar is available over the Internet.
It can be viewed via the World-Wide Web at
http://www.pa.msu.edu/abrams/SkyCalendar/Index.html
If you would like a printed sample of the January issue, please send
a long, self-addressed stamped envelope to:
January Sky Calendar
Abrams Planetarium
Michigan State University
East Lansing, MI 48824
Each month, the Department of Physics and Astronomy at Michigan State
University makes the Skywatcher's Diary available over the Internet. It
can be accessed at http://www.pa.msu.edu/abrams/SkyWatchersDiary/Diary.html
Current and back-issues of the Skywatcher's Diary are available in our
archives at
http://www.pa.msu.edu/abrams/SkyWatchersDiary/Archives.html
ftp://www.pa.msu.edu/pub/swd/
Planet Summary for January: The Moon appears near planets
or first-magnitude stars on mornings of Jan. 2 and 3, 23, 27, 30, and 31,
and on evenings of Jan. 10, 13-15, 17, 20, and 22. There is a total lunar
eclipse on the night of Thursday, Jan. 20; see Diary.
Evening Planets: Jupiter, of mag. -2.5 to -2.3, is the brightest
evening "star," high in SE to SSW at dusk. Saturn, at mag. +0.2
to +0.3, is the bright object high in ESE to S at dusk, 15 degrees to 13
degrees to Jupiter's east. In early January, rings of Saturn are tipped
19 degrees from edge-on, the minimum angle for this year. Mars glows
at mag. +1.0 to +1.2 in SW to WSW at dusk. Look 57 degrees to 36 degrees
west (lower right) of Jupiter. During January, the span of Mars-Jupiter-Saturn
shrinks from 72 degrees to 49 degrees. Keep watching until mid-April, when
the three planets will fit into a field just 5 degrees across! The Abrams
Planetarium Sky Calendar will illustrate them frequently until then.
Mercury: See Diary entry for Jan. 31. Morning
Planet: Venus is brilliant in SE at dawn, and appears lower at month's
end.
Skywatcher's Diary: January 2000
Please note: in Skywatcher's Diary, morning events are described on the
previous date.
Saturday, January 1
Venus shines in the SE an hour before sunrise throughout January. On Sunday
morning, look for the waning crescent Moon, four days before New, about
7 degrees upper right of Venus, and reddish Antares, heart of the Scorpion,
10 degrees below the brilliant planet. Before dawn brightens Sunday and
Monday, look for the 3rd-magnitude star Beta in the Scorpion's head, just
over one degree to Venus' lower right.
Sunday, January 2
Here's a very pretty gathering an hour before sunrise on Monday: A slender
waning crescent Moon with earthshine on its dark side, with Venus about
4 degrees to its upper right, and the reddish star Antares twinkling 9
degrees below Venus and 8 degrees to Moon's lower right. Look again on
Tuesday morning.
Monday, January 3
An hour after sunset, Jupiter, the most brilliant evening "star," is high
in SSE with Saturn just 15 degrees to its east (left). Mars is in SW 55
degrees west (lower right) of Jupiter. The lineup of Mars-Jupiter-Saturn
now spans 70 degrees across the sky. Keep watch until mid-April, when the
three planets will converge into a rare gathering just 5 degrees across,
low in the western sky at dusk.
An hour before sunrise on Tuesday, the most distant Moon of this
year is a thin crescent low in SE, 14 degrees lower left of brilliant Venus.
Antares, heart of Scorpius the Scorpion, twinkles 8 degrees below Venus.
Tuesday, January 4
On Wednesday about 40 minutes before sunrise, the very thin old crescent
Moon is just above the horizon, 30 to 35 degrees south of east and 25 degrees
lower left of Venus. From mid-Michigan, less than 30 hours remain until
New Moon.
Wednesday, January 5
An hour after sunset, the striking constellation Orion the Hunter is very
low in E to ESE in deep blue twilight. His brightest stars are blue-white
Rigel in ESE marking his foot, and reddish Betelgeuse in E marking his
shoulder. Midway between them is his belt, a vertical line of three stars,
almost equally spaced. Rising almost 45 degrees farther north along the
horizon are the Gemini twins, Castor 4-1/2 degrees above Pollux. At this
time of year, as we look toward the constellation Gemini, we are facing
directly away from the Sun.
Thursday, January 6
The Moon is New today at 1:14 p.m. EST today and not visible. The first
chance to see the Moon in the new lunar cycle will come on Friday, very
soon after sunset. More tomorrow.
Friday, January 7
From Stardust to Life: A Cosmic Journey opens at Abrams Planetarium.
Showtimes are Fridays and Saturdays at 8:00 p.m., and Sundays at 4:00 p.m.
For more information, call our recorded showline at (517) 355-4672.
First chance for most North Americans to see the young Moon should
occur by about half an hour after sunset this evening. Look for the slender
crescent very low, some 30 to 35 degrees south of due west. Binoculars
give a better view. For skywatchers in central lower Michigan at that time,
the 28-1/2-hour-old hairline Moon will then be only 4 degrees above the
horizon and will set in about another half hour. For followers of Islam,
the sighting of this Moon begins the month of Shawwal and ends the holy
fasting month of Ramadan.
In the southeast an hour before sunrise on Saturday, brilliant Venus
passes 6 degrees north of reddish Antares, heart of Scorpius. Look for
the star to the lower right of the planet.
Saturday, January 8
An hour after sunset, the crescent Moon with earthshine illuminating its
dark side is a pretty sight low in SW. Note first-magnitude Mars some 22
degrees to Moon's upper left, and bright Jupiter high in SSE with Saturn
15 degrees left. The Moon will pass these three planets on Jan. 10, 14,
and 15. Binoculars may show another planet near the Moon if the sky is
very clear at nightfall: Look for the 4th-mag. star Theta in Capricornus
a degree or two above the Moon. Sixth-mag. Uranus is 1.4 degrees upper
left of Theta.
Sunday, January 9
Our family show, The Little Star That Could, opens today at Abrams
Planetarium. Shows are presented Sundays at 2:30 p.m. Our feature show,
From Stardust to Life: A Cosmic Journey, is presented at 4:00 p.m.
Early this evening, from Great Lakes region to northern New England
and eastern Canada, the waxing crescent Moon occults or covers the 3rd-magnitude
star Delta in Capricornus or Deneb Algedi, tail of the Sea-goat. The disappearance
behind Moon's dark side takes place in bright twilight from Toronto at
5:19 p.m. EST and Pittsburgh at 5:27 p.m.; shortly after midtwilight from
Burlington VT at 5:30 p.m. and Albany NY at 5:37 p.m.; and in deep twilight
from Portland ME at 5:43 p.m. Use a telescope to see the reappearance of
the star at the Moon's bright edge, in bright twilight from Chicago at
5:01 p.m. CST and from East Lansing and Detroit MI at 6:03 p.m. EST; in
mid-twilight from Pittsburgh at 5:57 p.m. and Cleveland at 6:01 p.m.; in
deep twilight from Burlington VT and Toronto at 6:04 p.m., from Montreal
at 6:06 p.m., and from Portland ME at 5:57 p.m. Grazing occultation: The
Moon's southern cusp (point of the crescent) grazes Delta Capricorni --
causing the star to disappear and reappear behind mountains on the Moon's
edge -- as seen along a very narrow track beginning in WV in bright twilight
at 5:43 p.m. EST, through western MD, eastern PA, southeastern NY, northwestern
CT, central MA in deep twilight at 5:50 p.m., southeastern NH, extreme
southeastern ME, then across water to Nova Scotia. From north of that line,
a total occultation occurs; from south of that line, as from New York City
and Boston, the Moon narrowly misses the star. For more information, visit
the website: http://www.lunar-occultations.com/iota
Monday, January 10
In SW this evening, the Moon slides 2 or 3 degrees to the south of Mars.
Look for the first-magnitude reddish planet to the right or upper right
of the 4-day-old crescent. Can you see Fomalhaut, mouth of the Southern
Fish, low in SSW, 18 degrees to Moon's lower left? By the end of this week,
the Moon will pass two additional planets. Look nightly.
Tuesday, January 11
By an hour after sunset this evening, the Moon has travelled just over
a quarter of the distance from Mars in SW to bright Jupiter high in the
southern sky. Mars and Jupiter are now 50 degrees apart; they'll be only
one degree apart on April 5. Keep watching!
Wednesday, January 12
An hour after sunset this evening, the waxing crescent Moon, one-third
full, is near the halfway point from Mars in SW toward bright Jupiter high
in the southern sky. Mars-Jupiter are 49 degrees apart. Saturn is 14 degrees
east (left) of Jupiter.
Thursday, January 13
Evenings during Jan. 10-15, the waxing Moon passes all three bright outer
planets, while moving along a path south of the line joining them. An hour
after sunset tonight, the fat crescent is high in the southern sky, with
bright Jupiter about 11 degrees upper left. Saturn is 14 degrees left of
Jupiter, while Mars is in SW 48 degrees to Jupiter's right. Make your plans
now to observe the total lunar eclipse on the night of Thursday, Jan. 20,
one week from tonight. The umbral eclipse, or Moon's encounter with the
dark central core of Earth's shadow, will last nearly 3-1/2 hours, from
10:01 p.m. to 1:26 a.m. EST (7:01 p.m. to 10:26 p.m. PST). Contact your
local planetarium or astronomy club to find whether they have plans for
a public viewing session. Folks in the East Lansing area can check for
a recorded announcement on the Abrams Planetarium STAR-line at (517) 332-STAR,
anytime after Jan. 10.
Friday, January 14
The Moon passed First Quarter phase this morning, several hours before
its rising just before midday today. By an hour after sunset, the slightly
gibbous (more than half) Moon is high in SSE to S, just over 90 degrees
(a quarter-circle) east of the Sun. Bright Jupiter is 5 or 6 degrees upper
right of Moon, while Saturn is 11 or 12 degrees to Moon's upper left.
Our feature show, From Stardust to Life: A Cosmic Journey,
is presented 8:00 p.m. tonight and Saturday at Abrams Planetarium, and
at 4:00 p.m. on Sunday.
Saturday, January 15
An hour after sunset, the waxing gibbous Moon, now two-thirds full, is
high in SE to SSE. Saturn is 4 or 5 degrees to Moon's upper right, while
bright Jupiter is in south, 14 degrees right of Saturn. Aldebaran, eye
of Taurus, is in ESE, about 26 degrees lower left of Moon. Mercury, at
superior conjunction on the far side of the Sun today, will emerge into
the evening sky by early February, joining the three outer planets already
visible. Venus is the only bright planet in the morning sky.
Sunday, January 16
Our family show, The Little Star That Could, is presented at 2:30
p.m. today at Abrams Planetarium, and our feature, From Stardust to Life:
A Cosmic Journey, at 4:00 p.m.
An hour after sunset, first-magnitude Aldebaran, eye of Taurus,
is in ESE, 12 degrees lower left of the waxing gibbous Moon. Bright Jupiter
is high in S, while Saturn appears nearly halfway from Jupiter toward the
Moon. Mars is in SW. Notice the lineup, in order from west to east, of
Mars-Jupiter-Saturn-Moon-Aldebaran, 90 degrees long. Mars- Jupiter-Saturn
now span 60 degrees of sky. Keep watching until mid- April, when all three
planets will fit into 5 degrees.
Monday, January 17
Face ESE one hour after sunset, and note the waxing gibbous Moon with Aldebaran,
eye of Taurus the Bull, about 3 degrees upper right. For the next eight
hours until Aldebaran sets, the separation of Moon and star will widen
by about half a degree each hour. Look again on Tuesday evening.
Tuesday, January 18
The Moon, with just over two days until Thursday night's total lunar eclipse,
is in the east 1-1/2 hours after sunset. Betelgeuse, Orion's shoulder,
is 12 degrees to Moon's lower right, and Aldebaran about 17 degrees to
Moon's upper right. Pollux, the brighter of the Gemini twins, is in ENE
about 27 degrees to Moon's lower left. These three stars, all with surface
temperatures lower than the Sun's, all show a reddish tint to the unaided
eye. Compare their color to that of Rigel, Orion's foot.
Wednesday, January 19
Within an hour after sunset, Pollux and Castor, heads of the Gemini twins,
are about 14 degrees to the Moon's left, and Betelgeuse, shoulder of Orion,
is 19 degrees to Moon's upper right. Procyon, bright star of Canis Minor,
the Lesser Dog, is low in east about 18 degrees to Moon's lower right.
The name Procyon means "before the Dog," referring to the appearance of
Sirius, the Dog Star, rising not long after Procyon is seen. Follow Orion's
belt down to Sirius rising in ESE. If Sirius isn't already visible, it
soon will be!
Don't miss tomorrow night's total lunar eclipse. Contact your local
planetarium or astronomy club to find whether they have plans for a public
viewing session. Folks in the East Lansing area can check for a recorded
announcement on the Abrams Planetarium STAR-line at (517) 332-STAR, after
Jan. 10.
Thursday, January 20
A few minutes before the Sun sets in WSW, try to spot the Full Moon rising
in the opposite direction, ENE. From East Lansing, MI both Sun and Moon
are one degree above opposite horizons 10 minutes before sunset. The opposition
of Sun and Moon becomes more precise later this evening, during the total
lunar eclipse, which occurs as Moon passes through the umbra, or dark central
core of Earth's shadow. All stages of umbral eclipse are visible from all
of N. America except the western Aleutian Islands. For viewers in eastern
U.S., the event begins late in the evening and continues well past midnight,
as follows: Moon enters umbra 10:01 p.m. EST, total eclipse from 11:04
p.m. until 12:23 a.m. EST, Moon leaves umbra 1:26 a.m. EST. From the West
Coast, the local time of the eclipse is three hours earlier: Moon enters
umbra 7:01 p.m. PST, total eclipse from 8:04 p.m. until 9:23 p.m. PST,
Moon leaves umbra 10:26 p.m. PST. In Hawaii, the Moon, just entering total
eclipse at 6:04 p.m., rises invisibly around sunset and becomes visible
as the sky darkens. Totality ends at 7:23 p.m. Hawaii time as the Moon
begins to emerge from the umbra, and the Moon completely leaves the umbra
at 8:26 p.m. HST.
What colors will you see on the Moon during totality? The Earth's
shadow projected on the Moon during lunar eclipse is usually a deep reddish-orange
color, from sunlight which passes close to Earth and is bent, by our atmosphere,
into the shadow and onto the Moon. The appearance of the Moon varies considerably
from one eclipse to another. At deepest eclipse, at 11:43 p.m. EST (8:43
p.m. PST), Moon's northern limb is deep within umbra and narrowly misses
the center of Earth's shadow. So that part of the Moon's disk is likely
to appear very dark. Stars around the Moon at mid-eclipse: Note the two
bright stars Pollux and Castor, the Gemini twins, 4-1/2 degrees apart,
above the Moon. A line from Castor to Pollux extended about 10 degrees
points to the totally eclipsed Moon. In dark-sky locations, the Beehive
cluster in Cancer appears as a faint smudge of light 6 degrees or 7 degrees
to the Moon's east. Binoculars resolve the smudge into stars and should
give fine views of the colorful eclipsed Moon.
Friday, January 21
Our feature show, From Stardust to Life: A Cosmic Journey, is presented
8:00 p.m. tonight and Saturday at Abrams Planetarium, and at 4:00 p.m.
on Sunday.
Watch the Moon, one day past Full, rise in ENE nearly one hour after
sunset. By two hours later, the star Regulus, heart of Leo the Lion, is
visible about 15 degrees lower left of the Moon. On Saturday an hour before
sunrise, the Moon is in west, with Regulus about 10 degrees upper left.
Check again Saturday evening and on Sunday morning.
Saturday, January 22
At nightfall, Mars is in SW to WSW, with the Great Square of Pegasus to
its upper right. Tonight and Saturday, the west side of the Great Square,
extended 22 degrees south (lower left), points the way to Mars. Three hours
after sunset, the Moon is low, north of east, with the star Regulus less
than 2 degrees to its lower right. From East Lansing, MI, Moon and star
are closest about 4-1/2 hours after sunset; by an hour before sunrise on
Sunday, they're in WSW to W, with Regulus 4 degrees to Moon's lower right.
Sunday, January 23
Our family show, The Little Star That Could, is presented at 2:30
p.m. today at Abrams Planetarium, and our feature, From Stardust to Life:
A Cosmic Journey, at 4:00 p.m.
An hour before sunrise on Monday, Venus is low in SE, with reddish
Antares, heart of Scorpius, twinkling in SSE 21 degrees to Venus' upper
right.
Monday, January 24
The three bright outer planets lie along a line 54 degrees long across
the sky, stretching from high in the south to lower in the SW, an hour
after sunset. Mars-Jupiter are 41 degrees apart, Jupiter-Saturn are 13
degrees apart. Keep watch until April.
Conjunctions, or pairings, of Jupiter and Saturn occur about every
20 years. In the spring of the year 2000, for the first time since 1981,
Jupiter will overtake Saturn, but on the date of their closest pairing,
May 28, they'll be hard to see in bright morning twilight from mid-northern
latitudes. After that event, their next conjunction (a very close one!)
will be visible in the evening sky on December 21, 2020. (Mark your calendar!)
For lifetime naked-eye planet-watchers, Jupiter and Saturn mark the slow
hands of the great celestial clockwork of the solar system.
The daily sky diagrams on the Abrams Planetarium Sky Calendar
makes following the Moon and planets easy and fun. Subscriptions are $9.00
per year, starting anytime, from Abrams Planetarium, Michigan State University,
East Lansing, MI 48824. Sky Calendar is also one of the benefits
of membership in the Friends of Abrams Planetarium (a one-year Individual
Membership, tax-deductible, is $25 per year; other categories are available).
Coming issues of the calendar will illustrate the simultaneous appearance
of four planets at dusk in February, and the compact gathering of Mars,
Jupiter, and Saturn at dusk in April.
Tuesday, January 25
An hour before sunrise on Wednesday, the waning gibbous Moon, two-thirds
full, is in SSW to SW. The first-magnitude star Spica, spike of wheat or
ear of corn in the hand of Virgo, is about 11 degrees to Moon's lower left.
Wednesday, January 26
Face SSW an hour before sunrise on Thursday to spot the Moon, just over
half full, with first-magnitude blue-white Spica about 7 degrees lower
right.
Thursday, January 27
About 1-1/2 hours before sunrise on Friday, the half-illuminated Moon is
nearly south, with the 3rd-magnitude star Alpha in Libra 6 or 7 degrees
to its lower left. Binoculars split this star into an easy double, and
reveal much detail near the Moon's terminator, or day-night boundary, where
the Sun is setting and illuminating the lunar landscape at a grazing angle.
The Last Quarter Moon, 90 degrees or one-quarter circle west of the Sun,
can be followed until it sets in WSW, within an hour before midday on Friday.
Friday, January 28
Our feature show, From Stardust to Life: A Cosmic Journey, is presented
8:00 p.m. tonight and Saturday at Abrams Planetarium, and at 4:00 p.m.
on Sunday. Our family show, The Little Star That Could, will be presented
at 2:30 p.m. on Sunday.
On Saturday 1-1/2 hours before sunrise, the fat waning crescent
Moon is in SSE. Antares, red supergiant star marking the heart of the Scorpion,
is 20 degrees to Moon's lower left. A curved row of three stars of 2nd
and 3rd magnitude between Moon and Antares marks the front of the Scorpion's
head. Brilliant Venus has just risen in ESE to SE. As it rises higher,
look for a 3rd-mag. star 3 degrees to its lower right. It is Lambda in
Sagittarius, top of the Teapot.
Saturday, January 29
An hour before sunup on Sunday, the waning crescent Moon is in SSE, with
reddish Antares, heart of Scorpius, twinking 10 degrees below. Brilliant
Venus is low in SE. Keep watch daily! A beautiful pairing of Moon and Venus
will occur on the morning of February 2, Groundhog Day!
Sunday, January 30
On Monday an hour before sunrise, the waning crescent Moon is in SE to
SSE, with Antares 10 degrees lower right. Venus is low in SE about 22 degrees
to Venus' lower left.
Monday, January 31
Beginning 30 minutes after sunset, using binoculars, look just above the
WSW horizon for Mercury. Observe from a place with an unobstructed view,
and you will be able to follow Mercury for 10-15 minutes if the sky is
very clear. Just before Mercury sets, can you spot Mars 29 degrees to its
upper left? Much easier to see are bright Jupiter high in SSW with Saturn
even higher in S, 13 degrees to Jupiter's upper left. Mercury gets higher
and easier to see this week, and then it will be possible to see all four
of these planets simultaneously with unaided eye through the first three
weeks of February.
An hour before sunrise on Tuesday, the waning crescent Moon is in
SE. Brilliant Venus is within 12 degrees to Moon's lower left. Be sure
to look again on Wednesday!