Each month, the Department of Physics and Astronomy at Michigan
State University also makes Skywatcher's Diary available over the
Internet. It can be accessed via a World-Wide Web browser such as
Netscape or Mosiac, directly at URL:
The Skywatcher's Diary is also available via anonymous ftp at:
www.pa.msu.edu in the directory /pub/swd
Don't miss the lunar eclipse on Wednesday, April 3 (unless you're too
far west to see it). Details below.
At dusk in April, brilliant Venus is well up in W to NW at dusk, and
sets four hours after sundown early in month. This early spring
appearance of Venus, placing the planet very high in the sky at sunset
and making it visible for long afterward, won't be matched again until
the year 2004. Venus passes within a degree north of the Pleiades on
April 2 and 3 and within 10 degrees north of Aldebaran ten days later.
Mercury can be seen for most of April, in its best evening appearance of
the year, very low in WNW at dusk to the lower right of Venus. Comet
Hyakutake may put on a good show in the NW at nightfall, until it sinks
into bright twilight in the last few days of the month.
Dawn skywatchers can't help but notice bright Jupiter in SSE to S while
birds sing an hour before sunup. The Last Quarter (half) Moon is
nearby on April 10.
An hour after sunset on Astronomy Day, Saturday, April 20, the Moon
is beautifully framed by Aldebaran and the Hyades cluster, with Venus,
Mercury, and a possibly rebrightened Comet Hyakutake adding their
lustre to the scene. A diagram is available here.
The Lunar Eclipse of Wednesday, April 3:
- What you can see depends on your location: The farther east you are in
the U.S., the better; if you're too far west, you won't see it at all!
The Moon on Wednesday, April 3 will rise in total eclipse from the
Great Lakes, Southeast, Mississippi River, and Gulf Coast. But in these
regions it would be well not to have high expectations of what might
actually be seen: The disk of the Moon in total eclipse is too dim to be
seen in bright twilight, and within the U.S. it's likely to be seen only
from eastern states, after the sky has darkened. A total eclipse on
September 26 will occur later in the evening and be more widely visible.
What you'll see of the eclipse on April 3 depends on your location.
From New England, New Jersey, and eastern New York state, Moon
rises already in partial eclipse, and all later stages, including totality,
happen with Moon above horizon. For rest of eastern and central U.S.
westward to Minnesota and eastern third of Texas, the Moon rises
invisibly in total eclipse. In mid-Michigan, for example, where the
Moon rises in the middle of totality, the Moon isn't likely to be seen
until it begins to emerge from Earth's shadow, at 7:53 p.m. EST. Still
farther west, from the Dakotas and rest of Texas west to central
Montana and western Arizona, Moon rises during the terminal partial
stages of the eclipse. Still farther west, Moon rises after the umbral
eclipse is all over.
During the lunar eclipse on Wednesday, Apr. 3, the farther east you are,
the more of the eclipse you'll see; the best places in U.S. to view totality
are New England, New Jersey, eastern New York, and the Atlantic
Coast down to North Carolina, after the sky has darkened enough to
allow observation of the dimly lit eclipsed Moon. Depending on the
darkness of Earth's shadow on the Moon, mid-totality at 7:10 p.m. EST
may be visible only from eastern New England. If the Moon at mid-
eclipse is uncharacteristically bright, it might be seen over more of
northeastern U.S.
Totality ends at 7:53 p.m. EST. By then evening twilight is over (the
sky is dark) in eastern New England and the eastern tip of Long Island,
and twilight is nearly over in North Carolina's Outer Banks and in
southeast Florida. Along a line from eastern Ohio to the middle of the
Florida panhandle, totality ends in the deep blue skies of nautical
twilight, with the Sun 12 degrees down and the Moon 11 degrees up.
Somewhere near that line and from all locations farther east, for a few
minutes after 7:53 p.m., the Moon will display a narrow bright sliver at
its lower edge, while the rest of the disk still in shadow appears a dim
rusty-grey color, giving the Moon the appearance of a beautiful diamond
ring, a term usually applied to a solar eclipse.
The farther west you are as totality ends, the brighter the sky will be,
and harder it will be to see the still-dimmed Moon. From mid-lower
Michigan to the Mississippi-Alabama coast, totality ends in mid-
twilight, with the Sun 9 degrees down and the Moon 8 degrees up;
unless the eclipse is unusually bright, totality will be noted only by the
Moon's absence. There and farther west to Minnesota and east Texas,
the Moon probably won't be seen until it begins to emerge from the
umbra at 7:53 p.m. EST (6:53 p.m. CST). Still farther west, from the
Dakotas and rest of Texas west to central Montana and western Arizona,
the Moon rises during the terminal partial stages of the eclipse. The
Moon is completely out of the umbra by 8:59 p.m. EST (7:59 p.m.
CST, 6:59 p.m. MST). If you're west of a line from central Montana to
western Arizona, you're out of luck -- the umbral eclipse is completely
over before moonrise! You'll have to wait for this year's second lunar
eclipse, on Sept. 26. It will occur later in the evening, so will be in
better view, higher in the sky for all skywatchers across the continental
U.S.
Enhancing the beauty of September's Harvest Moon total eclipse will be
the presence of Saturn just two degrees away during totality.
-
- At nightfall, find spectacular Venus in the west. About a degree from
this "evening star", to its upper right tonight, and to its lower right on
Wednesday, find the compact Pleiades, or Seven Sisters, star cluster.
Binoculars give the best view of this cluster of faint stars so close to the
brilliant planet.
Seen through a telescope these evenings, Venus is now about one-half
illuminated. Note the bright star Capella very high in WNW 29 degrees
upper right of Venus.
At nightfall on April 2, Comet Hyakutake will be about 2 degrees lower
right of the 2nd-magnitude star Mirfak, or Alpha in Perseus. Locate
Mirfak in NW, 27 degrees upper right of Venus, and 19 degrees lower
right of Capella. Starting Friday, April 5, moonlight won't interfere
with comet viewing if you look when the comet is highest in a dark sky,
right at nightfall.
On Wednesday, the Moon has a rendezvous with Earth's shadow. If
you're not too far west in the U.S., remember to observe the lunar
eclipse. For details, see above.
-
- Here are our local plans to observe the lunar eclipse at Abrams
Planetarium at Michigan State University. Viewing circumstances will
be very similar from mid-lower Michigan along a line southward to the
Mississippi-Alabama coast, except the times would be one hour earlier if
you're on Central time. See above for more information about the
visibility of the eclipse if you're viewing it from any other part of the
country.
At Abrams Planetarium, if skies are clear this evening, we are holding a
public viewing session for tonight's total lunar eclipse. In Michigan, the
Moon will rise in total eclipse right around sunset, but will probably
remain invisible in twilight until it begins to emerge from Earth's
shadow at 7:53 p.m. EST.
Our session will begin at 7:30 p.m., at the east end of the top level of
the parking ramp behind Abrams Planetarium (that's the end farther
from the Planetarium and closer to the Moon). While we're waiting for
the Moon to appear low in ESE, we'll watch early spring stars come
out, enjoy telescopic views of Venus in its "half moon" phase, binocular
views of Venus near the Pleiades star cluster, and of Comet Hyakutake
in NW below the Alpha Persei cluster. The session will end with
Moon's complete emergence from Earth's shadow at 8:59 p.m. EST.
-
- The Moon, now just past Full, rises 10 to 15 degrees south of due east
about an hour after sunset. Look for Spica about 6 degrees to Moon's
upper right. At dawn on Friday, the Moon will be in SW to WSW, with
Spica about 10 degrees to Moon's lower right.
-
- Dark skies return tonight for comet viewers. At nightfall, the Moon
won't be up yet, and Comet Hyakutake is in northwest, 23 degrees right
of Venus and 23 degrees lower right of Capella.Note the 2nd-magnitude
star Algol within 4 degrees to the comet's lower left. Early next week,
the comet will pass closely lower right of that star. The Moon rises just
over 2 hours after sunset from northern U.S. tonight, 20 degrees lower
left of Spica.
-
- At sunset, Venus is over 40 degrees up in the west. Within half an
hour, Mercury appears 35 degrees to Venus' lower right. Mercury is
easy to see in a few evenings and remains in view for rest of April. At
nightfall the Pleiades star cluster appears 3 or 4 degrees to Venus' lower
right. Comet Hyakutake remains 22 degrees from Venus tonight
through all next week, shifting from right to lower right of the planet.
An hour before sunrise on Easter Sunday, Moon is in SSW with
Antares, heart of Scorpion, 11 degrees to its lower left.
-
- Mercury becomes an easy evening"star" this week, closing from 34 to
29 degrees to the lower right of brilliant Venus. Look about 45 minutes
after sunset.
An hour before sunrise on Monday, face S to SSW to see the waning
gibbous Moon and the star Antares within 10 degrees to its lower right.
-
- As darkness falls, face west and note the star Aldebaran, eye of Taurus,
11 degrees left of brilliant Venus. A line from Aldebaran to Venus,
extended to the right twice as far past Venus, ends at the 2nd-magnitude
star Algol in NW. Tonight Comet Hyakutake is about one degree lower
right of Algol. As it approaches the Sun, the comet may brighten during
the next two weeks and develop a fine dust tail. Binoculars give the best
view.
An hour before sunup on Tuesday, the Moon is approaching due south.
Note Antares in SSW and bright Jupiter in SSE. Follow Moon's
progress Tuesday and next two mornings.
-
- With your arm fully extended, your fist covers about 10 degrees of sky.
With that in mind, use your fist to measure angular distances between
stars. About 45 minutes after sunset, find brilliant Venus in western
sky, then look very low in WNW for Mercury 32 degrees (about three
fists) to its lower right. Look very high 24 degrees upper right of Venus
for Capella, brightest star in NW quarter of the sky, but not as bright as
Venus. As sky darkens, Comet Hyakutake becomes visible within 22
degees right of Venus and 25 degrees lower right of Capella, the three
bodies forming a nearly equilateral triangle. Note the comet has a fuzzy
appearance, especially when viewed with binoculars. The 2nd-
magnitude star just over a degree above the comet is Algol.
An hour before sunup on Wednesday, the Moon is in SSE with bright
Jupiter 5 degrees to its lower left. The Moon is approaching Last
Quarter phase, half full, and 90 degrees or a quarter-circle west of the
rising Sun. This lunar phase is ideal for study with binoculars and small
telescopes; striking detail can be seen near the terminator (day-night
boundary).
-
- In W to WNW at nightfall, Venus, Capella, and Comet Hyakutake form
a large, nearly equilateral triangle 22 to 25 degrees on a side. Brilliant
Venus marks the lower left corner of the triangle, Capella marks the top,
and the comet the lower right corner. Tonight the star Algol may appear
within the comet's tail or near its edge -- a beautiful sight for binoculars!
In the predawn darkness of Thursday, about 1-3/4 hours before sunrise,
the Moon is in SE, just under half full. Bright Jupiter is 11 degrees to
Moon's right. Next year's bright Comet, Hale-Bopp, is now a distant
telescopic object of magnitude 8, some 3 or 4 degrees lower right of the
Moon, 8 degrees left of Jupiter, and one degree below the 5th-
magnitude star 56 Sagittarii. The view improves in coming days as the
Moon moves on.
-
- Today, Comet Hyakutake passed 21.5 million miles from Venus, at a
relative speed of nearly 172,000 miles per hour. Tonight as darkness
falls, look for the comet in NW, 22 degrees lower right of the brilliant
evening "star" Venus, and 2.5 degrees lower left of the 2nd-magnitude
star Algol.
-
- Tonight and Saturday, Venus passes Aldebaran, eye of Taurus the Bull.
This reddish first-magnitude star is within 10 degrees lower left of
Venus at nightfall, while the Pleiades cluster is nearly as far to Venus'
lower right. Aldebaran marks the top of the left arm of the V-shaped
Hyades cluster. Both Hyades and Pleiades are beautiful fields for
binoculars. Look for the Comet 22 degrees lower right of Venus and 3
degrees lower left of Algol.
-
- Tonight, Comet Hyakutake is nearly 61 million miles from Earth and 55
million miles from the Sun. Although it is speeding away from Earth,
the comet is rapidly closing in on the Sun. Watch for it to brighten
noticeably in the next week. At nightfall look low in NW, 22 degrees
lower right of Venus and 4 degrees lower left of the 2nd-magnitude star
Algol.
-
- Mercury is in excellent view this week; an hour after sunset, look in
WNW, 28 degrees lower right of brilliant Venus. As the sky darkens
further, look for Comet Hyakutake 23 degrees lower right of Venus and
20 degrees upper right of Mercury. With each passing day this week,
the comet is over 2.3 million miles closer to the Sun. The comet should
brighten and its tail develop nicely, in time for Astronomy Day,
Saturday, April 20.
-
Last easy chance to see the old Moon: 45 minutes before sunrise on
Monday, look for the thin old crescent very low, nearly due east.
Binoculars may show Saturn rising 7 degrees to Moon's lower left.
Saturn is higher and easier from southern states.
-
- Let Venus, the brilliant evening "star", guide you to some beautiful
fields for binoculars: Aldebaran and the Hyades star cluster 7 to 11
degrees to Venus' lower left; the Pleiades or Seven Sisters cluster 11
degrees to Venus' lower right; and Comet Hyakutake 16 degrees right
of the Pleiades and 24 degrees lower right of Venus.
-
- An hour after sunset, Mercury is low in WNW, 26 degrees lower right
of Venus. As the sky darkens, look for the Pleiades cluster between
them and 12 degrees lower right of Venus. Look also for Comet
Hyakutake 16 degrees right of the Pleiades, 24 degrees lower right of
Venus, and 17 degrees upper right of Mercury. In next 10 days, the
comet and the Pleiades sink lower each evening, remaining 16 degrees
apart through April 26. Day by day the comet sinks faster than the
cluster, and will disappear to the cluster's lower right.
For the latest predictions and reports on Comet Hyakutake, check the
following Websites:
http://www.skypub.com/comets/hyaku3.html#top
http://www.jpl.nasa.gov/comet/hyakutake/
-
- The Moon is New today at 6:49 p.m. EDT (3:49 p.m. PDT) and is not
visible. If you can spot the Moon shortly after sunset on Thursday, note
the time, and calculate the Moon's age (time elapsed since New).
Tonight Comet Hyakutake appears 25 degrees to Venus' lower right at
nightfall.
-
- Within half an hour after sunset, try for the young Moon very low, 10
to 15 degrees N of due west. Before spotting Moon, you'll probably see
Venus, about 40 degrees up in W at sunset. Mercury appears 25 degrees
to Venus's lower right, and the thin sliver of a crescent Moon is 8
degrees to Mercury's lower left. The Moon's age is 25 hours from
eastern New England, 26 hours from lower Michigan, and over 28
hours from the West coast.
This Saturday is National Astronomy Day, and this weekend many
planetariums and astronomy clubs are holding special events to celebrate
the occasion. Contact your local group and join in! At Abrams
Planetarium, we'll offer "Spring and Summer Skies", this weekend
only, on Friday and Saturday at 8 p.m., and Sunday at 4 p.m. After the
evening shows if skies are clear, the Michigan State University
Observatory will be open for viewing of the beautiful gathering of the
Moon, Mercury, Venus, and Comet Hyakutake before the comet departs
from our evening skies.
-
- A very pretty sight for naked eye and binoculars awaits us tonight and
Saturday, about an hour after sunset: The crescent Moon is low in W to
WNW, with earthshine filling out the disk where no direct sunlight
reaches. Tonight Venus shines 21 degrees above the Moon, and
Mercury twinkles 8 degrees to Moon's lower right. Aldebaran and the
Hyades cluster glow to Moon's upper left and Venus' lower right. The
compact dipper-shaped Pleiades glitter about 10 degrees above Mercury
and the Moon. As the sky darkens further, Comet Hyakutake is 27
degrees lower right of Venus and 14 degrees uppper right of Mercury.
-
- Skywatchers gathering tonight for Astronomy Day will have some
especially wonderful sights for binoculars. Begin about an hour after
sunset with the two brightest objects in the night sky, low in W to
WNW: Venus 12 degrees to upper right of the crescent Moon. Next find
Mercury 24 degrees to Venus' lower right, and the star Aldebaran some
2 or 3 degrees to Moon's upper left. Direct your binoculars at the Moon,
and you'll see it is beautifully framed by the "V" of Aldebaran and the
Hyades cluster of stars. Next, find the Pleaides compact cluster of stars
about 3/5 of the way from Venus toward Mercury. Finally, as the sky
darkens, look for Comet Hyakutake: A line from the Moon to the
Pleiades, 11 degrees long, extended 16 degrees past the Pleiades, ends
near the Comet, low in NW.
Three bodies give clues to the Sun's location below the horizon this
evening. The Moon's bright crescent is illuminated by the Sun. If you
examine Venus through a telescope, you'll see it also displays a
crescent, about 3/8 full, with its bright side also toward the Sun. What
is the third clue? It's the comet, with its tail pointing away from the Sun!
For a rendering of this gathering, click here.
-
- An hour after sunset, Venus is 10 degrees to Moon's upper right,
Aldebaran 10 degrees to Moon's lower right. Mercury is 24 degrees
lower right of Venus. The Pleiades cluster is 8 degrees from Mercury
and 1/3 of the way toward Venus. As the sky gets darker, look for
Comet Hyakutake 13 degrees upper right of Mercury and 29 degrees
lower right of Venus. The comet passes 19.5 million miles from
Mercury today, and will pass 21.4 million miles from the Sun on May
1.
-
- From Earth's vantage point tonight, Mercury appears farthest from the
Sun in its current evening appearance, 20 degrees. An hour after sunset,
locate Mercury 24 degrees to the lower right of brilliant Venus. To help
you estimate that distance, tonight Venus appears 18 degrees to the
Moon's lower right, and Betelgeuse, shoulder of Orion, appears 11
degrees to Moon's lower left. Aldebaran, eye of Taurus, appears 12
degrees lower left of Venus. As twilight deepens, look for the Pleiades
upper left of Mercury. A line from Aldebaran to the Pleiades, 14 degrees
long, extended 16 degrees, ends near Comet Hyakutake, in NW.
-
- An hour after sunset, Procyon, Little Dog Star, is 15 degrees left of the
Moon. The twins, Pollux and Castor, are a similar distance above the
Moon. As twilight deepens, but before sky darkens completely, a line
from the Moon to Venus, nearly 30 degrees long, extended about as far
past Venus to NW horizon, locates the soon-to-depart Comet
Hyakutake.
-
- An hour after sunset Procyon is 10 degrees to Moon's lower left. Pollux
and Castor are to Moon's upper right. From northern U.S. tonight,
Comet Hyakutake still sets in a dark sky, barely after the end of
twilight. The best time to look may be about 1-1/4 hours after sunset,
depending on the comet's brightness. Look very low in NW, 32
degrees lower right of Venus and 13 degrees right of Mercury. If the
comet brightens sharply on its approach to the Sun, it may be visible for
a few more evenings, in bright twilight.
-
- The Moon, near First Quarter phase, is about 90 degrees east of the Sun
in the afternoon and evening sky. Note the Moon's shape is half full,
ideal for using binoculars to see surface features near the terminator
(day-night boundary).
Tonight, Comet Hyakutake is only 16 degrees from the Sun, and so can
be seen only in twilight, and only if it's bright enough. From a site with
an unobstructed view toward NW, look 1 to 1-1/4 hours after sunset,
33 degrees lower right of Venus and 14 degrees lower right of Mercury.
It's possible the comet's tail could extend above the horizon after dark.
-
- One hour after sunset, the Moon is high in SSW. Regulus, heart of Leo,
is 11 degrees to its upper left. From lower Michigan, Comet Hyakutake
sets in NW only 1 hour 20 minutes after sunset. Try about an hour after
sunset, 14 degrees lower right of Mercury.
-
- The Moon is high in S at dusk, with Regulus 5 degrees to upper right.
Mercury is of first magnitude, but fading fast. Aiming binoculars low in
WNW within an hour after sunset, can you still see Mercury with the
Pleiades 3 degrees above? Try also for the comet 15 degrees to
Mercury's lower right.
-
- Have you seen Saturn yet since it was beyond the Sun in mid-March?
An hour before sunrise on Monday, look barely above eastern horizon.
With Saturn so low, viewing conditions are poor for telescopic viewing
of the rings, now tipped 4 degrees from edgewise with their illuminated
south face visible. The view will improve in coming months as Saturn
rises earlier.
-
- Brilliant Venus is still well up in W to WNW at dusk, but it will rapidly
get lower next month. Venus will also show striking changes when seen
through a telescope. Next month, Venus will get close enough to Earth
so that its crescent phase will be observable even through 7-power
binoculars. The key is to observe Venus in the daytime, or shortly after
sunset, to avoid its brilliant glare against a darkened sky. On Tuesday
and Wednesday Venus will pass within a degree of the northern horn of
Taurus the Bull. Look nightly.
-
- The Moon is in SE at dusk with the first-magnitude star Spica 13
degrees to its lower left. Spica marks the spike of wheat in the hand of
Virgo. Look again Wednesday evening, and you'll find Spica just 2
degrees to the Moon's south (lower right).
On Wednesday morning, May 1, Comet Hyakutake passes only 21.4
million miles from the Sun, and begins its estimated 9,000-year journey
to the dark, cold outer reaches of the solar system some 35 times as far
out as Pluto's average distance from the Sun. What will Earth be like
when the Comet returns some 18,000 years in the future?
From lower Michigan on Wednesday, Comet Hyakutake will rise 31
degrees north of due east about 35 minutes before sunrise. The comet
will be within 7 degrees upper left of the Sun, but if it's much brighter
than predicted, it could still be visible in bright twilight, shortly before
sunrise. On Thursday, the comet will rise barely 30 minutes before
sunup, less than 6 degrees directly above the Sun. To avoid the hazards
of looking at the Sun through optical equipment, look *before* sunrise.
For the latest predictions and reports on Comet Hyakutake, check the
following Websites:
http://www.skypub.com/comets/hyaku3.html#top
http://www.jpl.nasa.gov/comet/hyakutake/
