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: A solstice and a shower for December

This star map shows the Houston sky at 9 pm CST on December 1, 8 pm CST on December 15, and dusk on December 31.  To use the map, put the direction you are facing at the bottom. The Summer Triangle sets in the west.  This consists of the brightest stars in Cygnus, Lyra, and Aquila.  Mars outshines all the dim stars in the southwest.   Pegasus, the Flying Horse, is high in the south.  To the east, we see Orion, the Hunter, and Taurus, the Bull, finally entering the sky.  The brilliant stars of winter began their grand entry.

This star map shows the Houston sky at 9 pm CST on December 1, 8 pm CST on December 15, and dusk on December 31. To use the map, put the direction you are facing at the bottom.
The Summer Triangle sets in the west. This consists of the brightest stars in Cygnus, Lyra, and Aquila. Mars outshines all the dim stars in the southwest. Pegasus, the Flying Horse, is high in the south. To the east, we see Orion, the Hunter, and Taurus, the Bull, finally entering the sky. The brilliant stars of winter began their grand entry.

This month, Mars remains in the southwest at dusk this month as it moves through Capricornus. Mars continues to fade a little each night as Earth continues to leave it farther behind. 

Jupiter is now high in the south at dawn; it is the brightest thing there. 

Venus begins to emerge from the Sun’s glare late this month. Can you spot it low in the southwest at dusk by New Year’s Eve?

Saturn begins to emerge into the morning sky by mid-month. Look low in the southeast at dawn.

In December, the Big Dipper is below the horizon at dusk. As the Big Dipper sets, though, Cassiopeia is high above the North Star. This is a pattern of five stars in a distinct M or W shape. 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. We are beginning to face away from the center of the galaxy, looking at stars behind us in our own part (the Orion Spur) of our galaxy.

Moon Phases in December 2014:

Full: December 6, 11:26 am
Last Quarter: December 14, 11:53 am
New: December 22, 12:35 am
1st Quarter: December 28, 5:32 pm

At 10:03 pm on Sunday, December 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 December 2, and the latest sunrise will occur January 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 December 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 pm. 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 from 5pm to midnight Saturday night, December 13 for observing this meteor shower. Midnight is about when the Moon, approaching last quarter phase, will rise.

Click here for the Burke baker Planetarium Schedule.

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. 

Clear Skies!

 

Seeing Stars with James Wooten: Come out to the George for Astronomy Day November 8!

This star map shows the Houston sky at 8 pm CDT on November 1, 7 pm CST on November 15, and dusk 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 Mars to its left.   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 star map shows the Houston sky at 8 pm CDT on November 1, 7 pm CST on November 15, and dusk 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 Mars to its left. 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, Mars remains in the southwest at dusk this month as it pulls away from the teapot of Sagittarius. Mars continues to fade a little each night as Earth continues to leave it farther behind

Jupiter is now higher in the east at dawn; it is the brightest thing there. 

Venus is passing behind the Sun and thus out of sight this month. Superior conjunction (Venus in line with the Sun, on the far side of the Sun) was on October 25.

Saturn is also out of sight behind the Sun this month. Conjunction with the Sun is on November 18.

The Summer Triangle now shifts towards the west as the Great Square of Pegasus appears higher, approaching the zenith. As the autumn ‘intermission’ in between the bright stars of summer and winter continues, Houstonians with a clear southern horizon can try to find a star that few Americans get to see. Due south and very low to the horizon at about 10:00 pm in mid-November is Achernar, 9th brightest star in the sky. It marks the end of the river Eridanus, one of the dim watery patterns that fill the southern autumn sky. If you can find it, Achernar will seem of average brightness because it is shining through so much air. Still, it is a good way to remind yourself that the stars we see depend on our latitude, and that the sky on the Gulf Coast is similar to, but not the same as, what most Americans see. 

Moon Phases in November 2014:
Full: November 6, 4:22 pm
Last Quarter: November 14, 9:17 am
New: November 22, 6:31 am
1st Quarter: November 29, 4:06 am

Our annual Astronomy Day at the George Observatory is this Saturday, November 8!  On Astronomy Day we have activities from 3-10 pm, and all of the telescopes, even the ones that normally cost $5 to look through, are free.  What’s more, the weather looks just great so far!  Surf to www.astronomyday.net for more information.

Click here for the Burke Baker Planetarium Schedule.

On 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. 

There’s a Partial Solar Eclipse Happening October 23: Here’s what you need to know to see it!

 

There’s a partial solar eclipse happening Thursday, October 23 and you can see it all from Houston*!

 The New Moon of Thursday, October 23, 2014, aligns with the Sun and the Earth well enough to cast its shadow towards Earth. However, no one will see a total eclipse for two reasons. First of all, the Moon was at apogee (greatest distance from Earth) on October 18, and is therefore smaller than usual in our sky. As a result, it is not quite big enough to cover the Sun, and the only eclipse possible would be an annular eclipse. Also, the Moon shadow is aligned to a point in space just over the Earth’s upper limb, so nobody will even get to see an annular eclipse. The near miss, however, allows the penumbra, where the Moon partially blocks the Sun, to land on the Earth. With North America near the upper limb of the Earth at the time, Houston will be within the penumbra. Therefore we will see a partial solar eclipse, in which the Moon will cover almost a quarter of the Sun’s disk at most.

partialeclipse

At 4:59pm CDT, look for the Moon to take a ‘bite’ out of the Sun’s disk. The Moon covers the northern limb of the Sun, which is the right side of the Sun as it sets in the west. Maximum eclipse, with the Moon covering almost 1/4 of the Sun’s disk, is at 5:58.  At 6:43, the Sun sets while still in partial eclipse. After this, the next partial solar eclipse visible from Houston occurs August 21, 2017. 

ECLIPSE TIMES

Eclipse begins: 4:59 PM, CDT
Mid-eclipse: 5:58 PM
Sunset: 6:43 PM

The Museum’s own George Observatory in Brazos Bend State Park will be open to the public from 1:00 -6:00 p.m. on October 23 for observing the Sun and, starting at 5:00, the eclipse.  

*CAUTION: Never look directly at the Sun with the naked eye or through an unfiltered telescope. Permanent eye-damage will result. 

Blood Moon Strikes Back! Total Lunar Eclipse Wednesday, October 8!

A total eclipse of the Moon will occur early Wednesday morning, October 8. Houstonians will be able to see virtually the whole event, which happens right before dawn.

Lunar eclipses occur when the full Moon moves into the Earth’s shadow. The first part of the Earth’s shadow that the Moon will encounter is the penumbra. The penumbral shadow’s faintness means that sharp-eyed observers will notice only a slight dimming of the Moon between 3:14 AM and 4:15 AM. The Moon moves into the darkest part of the earth’s shadow, the umbra, at 4:15 AM, and will be totally eclipsed by 5:24 AM. Totality lasts until 6:25, at which time the Moon has crossed the shadow and begun emerging from the other side. The Moon is still emerging from the shadow (and thus still partially eclipsed) as it sets at 7:26.  Note that this eclipse happens close to dawn, which is when a Full Moon is about to set. Therefore, you’ll need an observing site clear of obstacles to the west so you can watch the setting Moon in eclipse.  (That’s why we’re not observing from George Observatory, as we have in the past. Our tree line would interfere with the view).

Eclipse Diagram - James Wooten

The Moon’s brightness during a total eclipse depends on the amount of dust particles in the atmosphere. A large amount of dust from a volcanic eruption, for example, can make the totally eclipsed Moon almost invisible. With little dust in our atmosphere, the Moon glows reddish-orange during totality. This is because only the Sun’s red light comes through the Earth’s atmosphere and falls on the Moon even while it is in the Earth’s shadow. As the diagram shows, the Moon will pass through the northern part of the shadow, for about an hour of totality. As a result, the southern limb, closer to the center of Earth’s shadow, will appear darker.  And since we’ll be watching the Moon set in the west, the northern limb will be to the right and the southern limb to the left.

This is the second of four consecutive total lunar eclipses in 2014 and 2015, all of which are visible in the USA.  We’ll see our next total lunar eclipse in Houston just before dawn on April 4, 2015.