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: Winter Stars Shift to the Southwest

This star map shows the Houston sky at 9 pm CST on March 1, 9 pm CST on March 15, and dusk on March 31.  To use the map, put the direction you are facing at the bottom.

This star map shows the Houston sky at 9 pm CST on March 1, 9 pm CST on March 15, and dusk on March 31. To use the map, put the direction you are facing at the bottom.

Jupiter comes to opposition on March 8, which is when Earth aligns with Jupiter and the Sun. That is why Jupiter is up all night long in early March. Face east in evening twilight to watch Jupiter rise. It outshines all stars we ever see at night, so you can’t miss it. Early risers will still see Jupiter setting in the west at dawn.

Venus is in the southeast at dawn, appearing lower to the horizon each morning this spring. Venus outshines all the stars we see at night, and in fact outshines everything but the Sun and the Moon. However, now it doesn’t rise until morning twilight, and will soon become lost in the Sun’s glare. How long can you follow it?

Mars is in the south at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition in May; it has now surpassed nearby Saturn in brightness.

Saturn is in the south at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars slowly approaches Saturn this month.


Brilliant winter stars shift towards the southwest during March. Dazzling Orion is almost due south at dusk. His three-starred belt is halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points up to Aldebaran in Taurus the Bull. To Orion’s upper left are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards the horizon. To Orion’s left, about level with Betelgeuse, is Procyon, the Little Dog Star.

From Sirius, look a little bit to the right and then straight down to the horizon. If your southern horizon is clear of clouds and tall earthly obstacles, you’ll see Canopus, the second brightest star ever visible at night. This star is so far south that most Americans never see it and many star maps made in the USA omit it. (You must be south of 37 degrees north—the latitude of the USA’s Four Corners—for Canopus to rise). As you view Canopus, keep in mind that the sky we see depends on our latitude as well as on time of year and time of night.

Joining the winter stars are stars of spring rising in the east. Look for Leo, the Lion at dusk. Later in the evening, extend the Big Dipper’s handle to ‘Arc to Arcturus’ and then ‘speed on to Spica’; these stars rise at about 10:00 in early March but by 9pm on the 31st.

Moon Phases

Moon Phases in March 2016:

Last Quarter Mar. 1, 5:11 p.m.; Mar. 31, 10:17 a.m.

New Mar. 8, 7:54 p.m.

1st Quarter Mar. 15, 12:03 p.m.

Full Mar. 23, 7:01 a.m.

The New Moon of March 8 actually blocks the Sun, causing an eclipse of the Sun! However, it is visible only in Indonesia and the Pacific, where it will be March 9.

The Full Moon of March 23 passes though the penumbra, in which Earth partially blocks the Sun, but misses the true shadow or umbra. The resulting penumbral eclipse is only barely noticeable.

Sunday, March 13, is the second Sunday of the month. Accordingly, Daylight Saving Time begins at 2:00 am on that date. (Officially, the time goes from 1:59 to 3:00 am). Don’t forget to spring forward!

At 11:30 pm on Saturday, March 19, the Sun is directly overhead at the equator, shifting northward. That makes this the vernal (spring) equinox for us. Beginning on this date, day is longer than night for us in the Northern Hemisphere. Meanwhile, below the equator, days are shortening and now day is shorter than night. It is autumn down there.

On Friday, March 11, the brand new Burke Baker Planetarium re-opens to the public. Over Spring Break, come join us and enjoy images sharper than in any other theater!

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!

James G. Wooten
Planetarium Astronomer
Houston Museum of Natural Science

Seeing Stars with James Wooten: Five planets at dawn, leap day this February!

Star Map

Jupiter is now a late evening object, rising in the east. It rises by 9 p.m. on Feb. 1, and by Feb. 29 it comes up just before 7 p.m., which is during evening twilight. Jupiter comes to opposition on March 8, which is when Earth aligns with Jupiter and the Sun. That is why Jupiter is up all night long in late February and early March.

As dawn approaches this month, Jupiter will still be visible, this time high in the west.  Meanwhile, the four other visible planets will have risen as well. That’s right, February 2016  features all five naked-eye planets at dawn!

Venus is in the southeast at dawn. You can’t miss it, as Venus outshines all the stars we see at night, and in fact outshines everything but the Sun and the Moon.

Mars is in the south at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition next spring. 

Saturn is in the south southeast at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars slowly approaches Saturn this month.

Mercury is the biggest challenge to find. This month, though, Mercury is very close to Venus and to its left. Thus, once you find Venus, the brightest dot to its left is Mercury. 

Mercury is the first planet to leave the gathering as it heads back towards the Sun late this month. The cutoff date of Feb. 20 is somewhat arbitrary, though. It’s better to watch the sky and, using Venus as your guide, see for yourself when is the last day you can still see Mercury before losing it the Sun’s glare. The next to leave is Jupiter, which shifts into the evening sky after opposition. 

Taurus, the Bull, is high in the south. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the Hunter, takes center stage on winter evenings.  Surrounding Orion are the brilliant stars of winter. Orion’s belt points down to Sirius, the Dog Star, which outshines all other stars we ever see at night. The Little Dog Star, Procyon, rises with Sirius and is level with Orion’s shoulder as they swing towards the south. To the upper left of Orion’s shoulder is Gemini, the Twins.

Under Sirius and low to the southern horizon this month is a star that most Americans never get to see—Canopus. Representing the bottom (keel) of the legendary ship Argo, Canopus is the second brightest star ever visible at night. Thus, it is clearly noticeable along the southern horizon on February and March evenings. However, you must be south of 37 degrees north to see Canopus rise. (This is the line that divides Utah, Colorado, and Kansas from Arizona, New Mexico, and Oklahoma.)

The sky we see depends on our latitude as well as on the time of night and time of year.  From any given location in our hemisphere, there is an area of the sky around the North Star in which stars never set (circumpolar stars), and an equivalent area around the South Celestial Pole in which stars never rise. The closer you are to the pole, the larger these areas are. The closer you get to the equator, the fewer circumpolar stars there are, but there are also fewer stars that never rise for you. At the equator, no stars are either circumpolar or never visible; all of them rise and set as Earth turns. 

That’s why, down here in south Texas, the Big Dipper sets for a while although it’s always up for most Americans. On the other hand, Canopus, too far south to rise for most Americans, rises for us.

Moon Phases

Moon Phases in February 2016:

Last Quarter: Jan. 31, 9:28 p.m.

New: Feb. 8, 8:39 a.m.

First Quarter: Feb. 15, 1:46 a.m.

Full: Feb. 22, 12:20 p.m.

(February is so short that last quarter Moons occur on Jan. 31 and March 1, but not in February). 

The New Moon of Feb. 8 is the second New Moon after the winter solstice. Accordingly, it marks Chinese New Year. Welcome to the Year of the Monkey!

Monday, Feb. 29, is leap day. This day exists because our normal year of 365 days is too short. The true length of one Earth orbit around the Sun is 365 days and almost 6 hours.  No one wants to begin a year in the middle of a day, however. Therefore, we let the error add up over four years, until it becomes 24 hours, or one whole day, then add that day back to the calendar. Thus, February 29 occurs every four years. 

Almost 6 hours?  Well, alright, the difference between our orbit and our year is actually 5 hours, 49 minutes, and 16 seconds. That makes our system a very slight overcorrection.  To prevent that from adding up, we’ll skip leap day in 2100, 2200, and 2300. 

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: Four Planets are Visible

jan star report

Venus is in the southeast at dawn, approaching Saturn. Venus passes Saturn the morning of January 9; the two planets are less than one tenth of one degree apart! They’re easy to tell apart, as Venus outshines all the stars we see at night and is almost 100 times brighter than Saturn.

Mars is now in the south at dawn. Much dimmer than Venus now, Mars is getting a little brighter each day until its opposition next spring.

Jupiter now dominates the southwestern sky at dawn. As Jupiter approaches its opposition on march 8, you can also begin looking for it in late evening. By January 31, for example, Jupiter rises by 9:00 and will have cleared most horizon obstacles by 9:30 or 10.

In January, the Big Dipper is only partly risen at dusk. As the Big Dipper rises, though, Cassiopeia remains high. This is a pattern of five stars in a distinct W (or M) shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

Watch for the Great Square of Pegasus in the west at dusk. Taurus, the Bull is high in the south. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the Hunter takes center stage on winter evenings. Surrounding Orion are the brilliant stars of winter. Orion’s belt points down to Sirius, the Dog Star, which outshines all other stars we ever see at night. The Little Dog Star, Procyon, rises with Sirius and is level with Orion’s shoulder as they swing towards the south. To the upper left of Orion’s shoulder is Gemini, the Twins.

Moon Phases
Moon Phases in January 2016:

Last Quarter Jan. 1, 11:30 p.m.; Jan. 31, 9:28 p.m.

New Jan. 9, 7:31 p.m.

1st Quarter Jan. 16, 5:26 p.m.

Full Jan. 23, 7:46 am

At 4:49 pm on Saturday, January 2, the Earth was as close to the Sun as it will get this year. Thus we say that the Earth was at perihelion. However, Earth was only about 1.6% closer to the Sun than average on this date. That’s why being closer to the Sun at this time does little to warm us up. The effect of Earth’s tilt on its axis dominates the small effect of Earth’s varying distance in causing the seasons.

Although the shortest day (least daylight) occurs on December 21, the latest sunrise occurs for us about January 10. That’s because the Earth speeds up on its orbit as it approaches perihelion. This acceleration shifts sunrise, local noon, and sunset slightly later each day for the first part of this month. The effect is smaller than that of the Sun taking a slightly higher path across the sky, which normally dominates in causing later sunsets and earlier 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 until mid-January. Most people, then, will notice that both sunrise and sunset are now happening earlier than in December. As we move farther from the solstice, the effect of the Sun taking a slightly higher path each day again predominates.

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!

Geminid Meteor Shower offers a brilliant weekend at the George!

The annual Geminid Meteor Shower peaks this weekend, and we’ve got some tips for stargazers hoping to catch it.

The Geminids are unique among meteor showers because they are associated not with a comet but with an asteroid, 3200 Phaethon. Comet orbits are so oblong that that they cross Earth’s orbit almost at right angles. For most meteor showers, then, Earth doesn’t rotate us to face the debris field until after midnight. The less oblong orbit of an asteroid meets Earth’s orbit at a shallower angle. Thus, we rotate to face into the debris field earlier in the night, even before midnight. With Geminids, then, we see significant activity as early as 9 or 10 p.m., although the shower will likely peak just before dawn.

geminid

The Geminid meteor shower is one of the brightest, most active, and most remarkable annual stellar events.

A new moon falls on Thursday, Dec. 10 this year. That makes Sunday night’s moon a slender crescent which sets by 8 p.m. This should guarantee us nice, dark night for viewing once the shower gets going. The Geminid Meteor shower peaks every December and is one of the best, most reliable showers, producing an average of 100 meteors per hour.

They’re called the Geminids, by the way, because we see them seem to ‘radiate’ from an area of sky near Castor, a bright star in Gemini, the Twins. In December, Gemini is still rising at dusk, but it has cleared the horizon by 8 p.m., passes high overhead at about 1 a.m., and is in the west by dawn. Remember, though, that not all meteors will be in Gemini! They just seem to radiate from that direction, which means that wherever they appear, the streak will seem to move away from Gemini.

geminids-2014

Therefore, it’s best to lie on your back so you can observe as much of the sky as possible at once. Remember to have patience, as the 100 meteors per hour is about one or two per minute on average. One minute can be a long time if you waiting for something to happen.

84820023

Weather permitting, telescopes, including the Gueymard Research Telescope, will be available for public use at the George Observatory until 10 p.m. during the Geminid Meteor Shower event.

As with all showers, the Geminid Meteor Shower will be best viewed away from city light pollution, weather permitting. The George Observatory will be open Sunday night until midnight for observation. For directions to The George, located just an hour southwest of Houston, click here. Entry to Brazos Bend State Park is $7 per person; free for kids under 12. You don’t need any special equipment for viewing, just a chair, blankets and maybe some hot apple cider.