Seeing Stars with James Wooten: February 2013

Mercury briefly enters the evening sky this month. Greatest elongation (the greatest apparent distance from Sun) is February 16, so that’s when you’ll see it the longest.  However, you can begin looking in a few days. Because Mercury sets soon after the Sun, you’ll need a perfectly clear horizon right over the point of sunset at dusk.  On February 8, Mercury passes less than one degree from Mars, which is on its way out of the evening sky.

Jupiter was up all night long last month and is now almost overhead at dusk. Opposition, when Earth passed directly between Jupiter and the Sun, was January 3. Face high in the south at dusk and look for the brightest thing there (unless the Moon is also there), as Jupiter outshines all stars we ever see at night.

Sky Map: February 2013

Venus now rises while dawn brightens the sky; its morning apparition is ending. Soon Venus willl pass around the far side of the Sun from our perspective, and then reappear in the evening by summer.

Saturn remains in the morning sky this month. Look for it in the south-southwest at dawn.

Brilliant winter stars dominate the southern skies of February. 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. This winter the Bull also contains Jupiter.

Rising with Orion, and far to his 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.

Moon Phases in February 2013:
Last Quarter                  February 3, 7:57 am
New                               February 10, 1:22 am
1st Quarter                    February 17, 2:30 pm
Full                                February 25, 2:28 pm

The New Moon of February 10 is the second New Moon after the winter solstice.  Accordingly, it marks Chinese New Year. On this date the Year of the Dragon ends and the Year of the Snake begins.

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.

Would you like email updates on current events in the sky, at the planetarium, and at the George Observatory?  If so, send an email to astroinfo@hmns.org.

Seeing Stars with James Wooten: January 2013

Happy New Year! This January, Mars continues to fade as it drops into the Sun’s glare. It is low in the southwest at dusk.

Jupiter is now up all night long. Opposition, when Earth is directly between Jupiter and the Sun and Jupiter literally rises at sundown and sets at sunup, is Jan. 3. After that date, Jupiter only gets higher and more prominent in the evening sky. Face east/northeast at dusk and look for the brightest thing there (unless the Moon is also there), as Jupiter outshines all stars we see at night.

Venus is lower in the east at dawn than before. You can still observe it this month and next.

Saturn is a little higher in the morning sky this month. Look for it just in the south at dawn.

Sky Map: January 2013

The Great Square of Pegasus sets in the west, while brilliant winter stars shine in the south. Orion, the Hunter, is almost due south. His two dogs, represented by Sirius and Procyon, are to his left. Above Orion is Taurus, the Bull with Aldebaran as its eye. Gemini, the Twins, are to Orion’s upper left. Jupiter, outshining all stars in the night sky, is in Taurus between Aldebaran and the Pleiades. In the north, the Big Dipper has been out of sight under the North Star for a while. In January, though, you can look for the two pointer stars, which point at the North Star, peeking over trees and houses to the north/northeast.

Moon Phases in January 2013:
Last Quarter                  January 4, 9:58 p.m.
New                               January 11, 1:44 p.m.
1st Quarter                    January 18, 5:45 p.m.
Full                                January 26, 10:39 p.m.

At 11 p.m. on Tuesday, Jan. 1, the Earth passed as close to the Sun as it will get this year. Thus, Earth is now just past perihelion. If we’re closer to the Sun now, why is it cooler (even in Houston)? Notice how low the midday Sun is right about now. Six months from now, take note of how high the Sun is in June and July. That’s what makes it so much cooler now and so hot then.

The Earth’s orbit is, in fact, almost perfectly circular; there is only a 3-percent difference between perihelion and aphelion distance. The 23.44-degree tilt of the Earth makes the Sun appear high if we tilt towards it and low if we tilt away, and dominates the small effect of Earth’s changing distance.

The latest sunrise of the year (at Houston’s latitude) occurs on Jan. 10. Earth, just past perihelion, has sped up a little in its orbit since it is a little closer to the Sun. As a result, sunrise, local noon, and sunset have been happening a little later each day since early December. The noon Sun is ever so slightly higher at noon each day since the solstice (Dec. 21), but as of today, the Sun is still very close to its solstice height. Beginning Jan. 11, the noon Sun’s greater height in the sky again becomes the dominant effect (as it is for most of the year). From then until June, sunsets are getting later while sunrises are getting earlier.

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.

Would you like email updates on current events in the sky, at the planetarium, and at the George Observatory?  If so, send an email to astroinfo@hmns.org.

Seeing Stars with James Wooten: April 2012

April 2012 features four visible planets, visible at convenient evening hours!

Venus continues to appear high in the sky each night, outshining everything but the Sun and the Moon. Look for it in the west at dusk.

seeing stars april

This is the last month to see Jupiter in evening hours for some time. On the first few nights of April, Jupiter is low in the west — far below Venus. However, Jupiter appears slightly lower in the sky each night until it is lost in the Sun’s glare by month’s end. It outshines all stars we ever see at night, however, so it’s still not hard to find.

Mars has joined Jupiter and Venus as an evening object. Face east at dusk and look for the brightest point of light in that direction. Although not as bright as Venus or Jupiter, Mars still rivals the brightest stars in the night sky. However, Mars fades a little bit each night as Earth pulls away from it (on March 3, Earth passed between Mars and the Sun).

Saturn becomes an evening object this month. On April 15, Earth aligns with the Sun and Saturn, placing Saturn at opposition — just as Mars was last month.

Brilliant winter stars continue to dominate the western sky at dusk.  Orion, the Hunter, is almost due south. His two dogs, represented by Sirius and Procyon, are to his left.  To Orion’s right is Taurus, the Bull, with Aldebaran as its eye. Gemini, the Twins, are above Orion. Leo, the Lion, is approaching the zenith. In the east, you can use the Big Dipper’s handle to find two bright stars of spring. From the Big Dipper’s handle, arc to Arcturus and speed on to Spica.

Moon Phases in April 2012:

Full                            April 6, 2:19 p.m.

Last Quarter       April 13, 5:50 a.m.

New                           April 21, 2:19 a.m.

1st Quarter           April 29, 4:57 a.m.

Sunday, April 8 is the first Sunday after the first full moon following the first day of spring. Therefore, it’s Easter Sunday.

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.

Seeing Stars with James Wooten: March 2012

March 2012 features all five visible planets, visible at convenient evening hours!

Astronomy Day 2008

Venus continues to appear higher and higher in the sky each night, outshining everything but the Sun and the Moon.  Look for it in the west at dusk.  It is also still approaching Jupiter each night as March begins.  On the first few nights of March, Venus is just over 10 degrees below Jupiter in the west.  However, Venus continues to close that gap until March 13, Venus and Jupiter are side by side, with Venus on the right.  After that, Venus pulls away, appearing higher than Jupiter in the west at dusk.  Jupiter outshines everything in our sky except the Sun, the Moon, and Venus.  Venus and Jupiter thus make a spectacular pair in the west this month.

Mars has joined Jupiter and Venus as an evening object.  Face east at dusk and look for the brightest point of light in that direction.  Although not as bright as Venus or Jupiter, Mars has brightened enough to rival Sirius, the brightest star we ever see at night. On March 3, Earth passes between Mars and the Sun, putting Mars in our sky literally all night long (an alignment called opposition).

Mercury is ordinarily too close to the Sun to observe; only rarely is it far enough from the Sun to be still up after sundown.  Early March 2012 is one of those rare times, however.  During the first two weeks of March, look for Mercury low in the west at dusk, between Venus and the point of sunset.  Mercury is highest in the sky on March 5 and gets a little harder to see each day after that.

Saturn becomes a late evening object this month.  Look in the south southeast beginning at about 10:00 pm on March 1, and by 8:40 (just after twilight ends) on March 31.  Saturn is near the star Spica.  (From the Big Dipper’s handle, arc to Arcturus and speed on to Spica).

Big Dipper in a big sky

Brilliant winter stars continue to dominate the southern sky at dusk.  Orion, the Hunter, is almost due south.  His two dogs, represented by Sirius and Procyon, are to his left.  Above Orion is Taurus, the Bull with Aldebaran as its eye. Gemini, the Twins, are to Orion’s upper left.  Leo, the Lion, is rising in the east.

Below Sirius, just above the southern horizon, is a star second only to Sirius in brightness.  This is Canopus, which marks the keel (bottom) of the legendary ship Argo Navis.  Canopus is so far south, in fact, that most Americans never see it.  From the Gulf Coast, however, Canopus does rise.  February and March are the best months to see it at dusk.

Moon Phases in March 2012:

Full                               March 8, 3:41 am

Last Quarter                  March 14, 8:26 pm

New                              March 22, 9:38 am

1st Quarter                     March 30, 2:41 pm

At 12:13 am on Tuesday, March 20, the Sun is directly overhead at the equator.  This, then, is the vernal (spring) equinox, marking the official beginning of spring in the Northern Hemisphere.  In the Southern Hemisphere, summer turns to fall.

Visit www.hmns.org for the latest 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.