About James

James is the Planetarium Astronomer at the Houston Museum of Natural Science. He teaches students every school morning in the planetarium, and also answers astronomy questions from the public.

Seeing Stars with James Wooten: Comet ISON, Winter Solstice & the Geminid meteor shower

ev.owaThis is it. The final stargazing report of 2013. So let’s get to it, shall we?

Venus remains in the west at dusk for one more month. It outshines everything but the Sun and Moon, so you can begin observing it during deep twilight. Shortly after the new year begins, Venus shifts from the evening to the morning sky.

Jupiter will be up literally all night long early next month. In December 2013, then, it is not up at dusk but rises during the evening. Now you can see it rise in the northeast at about 8 p.m., just as Venus sets. By New Year’s Eve, Jupiter rises by 5:50 p.m., during twilight.

Mars remains in the morning sky. It continues to brighten a bit in the south at dawn.

Saturn has reappeared in the pre-dawn sky. Face southeast right before sunup to see it.

In December, the Big Dipper is below the horizon at dusk. As the Big Dipper sets, though, Cassiopeia rises. This is a pattern of five stars in a distinct W shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

The Summer Triangle sets in the west. Watch for the Great Square of Pegasus almost overhead at dusk now and in the west by Christmas. Taurus, the bull, rises in the east. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the hunter, rises shortly after dusk (by month’s end, it is already up at dusk). As Orion enters the evening sky, we transition from the relatively dim evening skies of autumn to the brilliant stars of winter.

Unfortunately, it appears that Comet ISON did not survive its close passage to the Sun this past Thanksgiving. At 12:48 p.m. CST on Thurs., Nov. 28, ISON passed just 1.7 solar radii above the Sun’s surface. This proved to be too close, as the Sun’s gravity tore ISON apart, causing it to shed much of its gas and dust. This left only a small remaining fragment to continue on ISON’s orbital path, a fragment too small to put on a naked-eye show on December mornings. Binocular observers, though, can still give it a try.

You can still find information showing ISON’s position, or you can view the full path.

If ISON survives perihelion this Thanksgiving (it has about a 50/50 chance), we could see it quite well between Thanksgiving and Christmas. More on this in the December update.

Moon Phases in December 2013:

New: December 2, 6:21 pm
1st Quarter: December 9, 9:12 am
Full: December 17, 3:28 am
Last Quarter: December 25, 7:49 am

At 11:11 a.m. on Sat., Dec. 21, the Sun is directly overhead at the Tropic of Capricorn, the farthest point south where this is possible. This puts the Sun as low as possible in our sky, and marks the winter solstice. In the Southern Hemisphere, the Sun is as high as possible in the sky — this is the summer solstice for them.

Although the winter solstice is the shortest day, the earliest sunset occurred on about Dec. 2, and the latest sunrise will occur Jan. 10. That’s because the Earth speeds up on its orbit as it approaches perihelion (closest approach to the Sun) next month. This acceleration shifts sunrise, local noon, and sunset slightly later each day this month and next. The effect is smaller than that of the Sun taking a lower path across the sky, which normally dominates in causing earlier sunsets and later sunrises. But the Sun’s apparent path varies very little near the solstice itself, allowing the secondary effect of the Earth approaching the Sun to predominate. For most people, then, (those who witness sunset but sleep through sunrise), days will seem to lengthen throughout December, although they don’t really begin lengthening until Dec. 21.

The Geminid meteor shower peaks this month, as it does every December. Along with the Perseids in August, the Geminids are one of the two most reliable meteor showers, producing on average about 100 meteors per hour. The Geminids are unique among meteor showers because they are associated not with a comet but with an asteroid, 3200 Phaethon. This means that with Geminids, we see significant activity much earlier in the night than with other showers.

Most meteor showers peak in the hours immediately before dawn. This is because what plows through the debris field is the leading edge of the Earth, and that’s the side going from night into day. Since Phaethon is an asteroid, however, debris along its orbital path forms a shallower angle to Earth’s orbital path, meaning that we begin to face into the debris field as early as 9 or 10 p.m. Meteors will seem to “radiate” from the constellation Gemini, hence the name of the shower. However, they may appear anywhere in the sky.

As always, you see more meteors the farther you are from big city lights, which hide dimmer ones. Our George Observatory will be open at 5 p.m. on Friday night, Dec. 13, to 1 a.m. on Saturday morning, Dec. 14, for observing this meteor shower.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

Seeing Stars with James Wooten: the Comet ISON & the end of Daylight Saving Time

Only one more month left in the year!

In November, Venus remains in the west at dusk. It outshines everything but the Sun and Moon, so you can begin observing it during deep twilight.

Jupiter is high in the morning sky this month. Look for it high in the west at dawn.

You can also look for Jupiter in the late evening sky in the east. It rises by 11:10 p.m. on November 1, and by 8:10 p.m. on November 30.

Mars, much dimmer than Jupiter, now pulls away from it in the morning sky. It now brightens a bit in the east at dawn.

Saturn is behind the Sun (at conjunction) on November 6, and thus out of sight most of the month. By Thanksgiving, you can try finding it low in the southeast at dawn.

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This star map shows the Houston sky at 10 p.m. CDT on November 1, 8 p.m. CST on November 15, and 7 p.m. on November 30. To use the map, put the direction you are facing at the bottom. The Summer Triangle is high in the west. This consists of the brightest stars in Cygnus, Lyra, and Aquila. The ‘teapot’ of Sagittarius sets in the southwest, with Venus to its right. Pegasus, the Flying Horse, is high in the east. To the south and east, we see a vast dim area of stars known as the “Celestial Sea,” where only Fomalhaut stands out.

This month, the Big Dipper is to the lower left of the North Star at dusk, and soon sets. As a result, it may be hard to see if you have trees or buildings north of you. As the Big Dipper sets, though, Cassiopeia rises. This is a pattern of five stars in a distinct W shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

Perhaps the most significant sight in our skies this month will be Comet ISON. That’s perhaps because ISON has never been in the inner solar system before and will never come back, so astronomers are unsure how it will behave.

There is some optimism, however, that ISON will brighten enough to be visible to the naked eye as it approaches the Sun this Thanksgiving Day. On Thanksgiving, when ISON is at its brightest, it will be too close to the Sun to observe. But you might notice it low in the southeast at dawn in the weeks leading up to Thanksgiving Day. You’ll be looking for a dim, diffuse object, so you’ll want to pick a site far from city lights and a morning with little or no moonlight. ISON passes close to the Star Spica on November 17.

With the help of the Internet, you can track ISON’s position, or view ISON’s full path.

If ISON survives perihelion this Thanksgiving (it has about a 50/50 chance), we could see it quite well between Thanksgiving and Christmas. I’ll have more on this in the December update.

Moon Phases in November 2013:
New:  November 3, 6:48 am
1st Quarter:  November 9, 11:58 pm
Full:  November 17, 9:15 pm
Last Quarter:  November 25, 1:29 pm

Sunday, November 3, is the first Sunday of the month. Accordingly, Daylight Saving Time ends at 2 a.m. that morning. (At 2 a.m., the time reverts to 1 a.m., such that the 1 a.m. hour happens twice). Remember to set all clocks back one hour on Saturday night, November 2, and enjoy your extra hour of sleep!

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

Seeing Stars with James Wooten: October’s “intermission” in the sky & Astronomy Day

The night sky in October is full of comings … and goings.

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Venus remains in the west at dusk. It outshines everything but the Sun and Moon, so you can begin observing it during deep twilight.

Saturn leaves the evening sky this month. For the first few days of October, you can look for it in evening twilight to the lower right of Venus. After mid-month, though, it’s hard to see. Saturn is behind the Sun (at conjunction) on Nov. 6.

Jupiter is higher in the morning sky this month. Look for it high in the south at dawn.

Mars, much dimmer than Jupiter, now pulls away from it in the morning sky. It remains in the east at dawn. On the morning of Oct. 15, look for it near Regulus in Leo.

In October, the Big Dipper is to the lower left of the North Star at dusk, and soon sets. As a result, it may be hard to see if you have trees or buildings north of you.  As the Big Dipper sets, though, Cassiopeia rises. This is a pattern of five stars in a distinct W shape, which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

Autumn represents sort of an “intermission” in the sky, with bright summer stars setting at dusk, while bright winter stars have not yet risen. The “teapot” of Sagittarius sets in the southwest at dusk. The Summer Triangle is high in the west.  Meanwhile, the Great Square of Pegasus is in the east, indicating the start of autumn. The stars rising in the east are much dimmer than those overhead and in the southwest, because when you face east at dusk in October, you face out of the Milky Way plane.

The center of our galaxy lies between Scorpius and Sagittarius, while the Summer Triangle is also in the galactic plane. Pegasus, on the other hand, is outside the plane of our galaxy and is a good place to look for other galaxies.

october13Moon Phases in October 2013:

New                         October 4, 7:33 p.m.

1st Quarter              October 11, 6:03 p.m.

Full                           October 18, 6:36 p.m.

Last Quarter            October 26, 6:41 p.m.

The full moon of Oct. 18 enters the penumbra, a region in which Earth partially blocks the Sun. Unlike the full shadow (umbra), however, the penumbra only imperceptibly darkens the Moon.

Sat., Oct. 12, is our annual Astronomy Day at the George Observatory, which lasts from 3 to 10 p.m. at our observatory in Brazos Bend State Park. See here for a full list of activities.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer.  If you’re there, listen for my announcement.

Seeing Stars with James Wooten: September 2013

Venus remains in the west at dusk. It outshines everything but the Sun and Moon, so you can begin observing it during deep twilight. On September 18, Venus passes Saturn (they are just over three degrees apart).

Saturn is now shining in the south/southwest at dusk. Although not as bright as Venus, it does outshine the stars around it, so you can’t miss it. Jupiter is higher in the morning sky this month. Look for it in the east at dawn. Mars, much dimmer than Jupiter, now pulls away from it in the morning sky. Look for it to Jupiter’s lower left in the morning sky at dawn.

Sky Map: September 2013In September the Big Dipper begins to appear to the lower left of the North Star. As a result, it may be hard to see if you have trees or buildings north of you. The Big Dipper gets lower and lower to the horizon each evening throughout autumn, and is actually gone by November.  As the Big Dipper sets, though, Cassiopeia rises. This is a pattern of five stars in a distinct W shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

Antares, brightest star of Scorpius, the Scorpion, is in the southwest, with the ‘teapot’ of Sagittarius to its left. The Summer Triangle is high overhead.  Meanwhile, the Great Square of Pegasus is in the east, indicating the start of autumn. The stars rising in the east are much dimmer than those overhead and in the southwest because when you face east at dusk in September, you face out of the Milky Way plane. The center of our Galaxy lies between Scorpius and Sagittarius, while the Summer Triangle is also in the galactic plane. Pegasus, on the other hand, is outside the plane of our galaxy and is a good place to look for other galaxies.

Moon Phases in September 2013:

New                                September 5, 6:35 am
1st Quarter                    September 12, 12:09 pm
Full                                 September 19, 6:12 am
Last Quarter                 September 27, 10:55 pm

At 3:44 p.m. on Sunday, September 22, the Sun is directly overhead as seen from the equator. Thus, this marks the autumn equinox, the official start of fall. On this date, the Sun sets at the North Pole and rises at the South Pole. Everyone in the world has the same amount of daylight.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.