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!

Seeing Stars with James Wooten: Lunar Eclipse on April 4

april stars

Mars remains in the west at dusk this month as it moves through Aries. Mars continues to fade a little each night as Earth continues to leave it farther behind. Later on this month, Mars begins to be lost in the glare of the Sun.

Mercury enters the evening sky as Mars leaves it. By April 30, Mars will be gone but Mercury will be low in the west northwest, near the Pleiades star cluster.

Venus is in the west at dusk. Look over the point of sunset for the brightest thing there.

Jupiter is now high in the sky, almost overhead, as soon as night falls. Jupiter outshines all stars we ever see at night, so it will be obvious when you look up at dusk.

Saturn is in the southwest at dawn.

Brilliant winter stars shift towards the west during April. Dazzling Orion is high in the southwest at dusk. His three-starred belt is halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points right to Aldebaran in Taurus the Bull. Above Orion are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins. Jupiter is among the Twins this month. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards south (left as you face west). Forming a triangle with Betelgeuse and Sirius is Procyon, the Little Dog Star.

Joining the winter stars are stars of spring in the south and east. Look for Leo, the Lion almost overhead at dusk. In the east, extend the Big Dipper’s handle to ‘Arc to Arcturus’ and then ‘speed on to Spica’.

Moon Phases in April 2015:

Full April 5, 7:05 am

Last Quarter April 11, 10:44 pm

New April 18, 1:56 pm

1st Quarter April 25, 5:55 pm

The Full Moon of April 4 passes through the Earth’s shadow, causing a total lunar eclipse. Unfortunately, the Moon clips the edge of the Earth’s shadow, allowing for only 5 minutes of totality. What’s more, for us the eclipse occurs near moonset and sunrise (which are almost simultaneous when there is a lunar eclipse). That puts the Moon low to the horizon during the eclipse; only those with clear views all the way to the western horizon can get a good look. It also means that totality falls during morning twilight.

Eclipse times:

Partial eclipse begins: 5:15 am
Totality 6:57-7:02 am
Moonset (still partially eclipsed) 7:13 am

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 Stars of Spring are Rising

March star report
Mars remains in the west at dusk this month as it moves through Pisces. Mars continues to fade a little each night as Earth continues to leave it farther behind. After this month, Mars begins to be lost in the glare of the Sun.

Venus is in the west at dusk. Venus overtook Mars on February 21; now watch Venus leave behind the much dimmer Mars throughout March.

Jupiter was up all night long in February; now it is high in the east as soon as night falls. Jupiter outshines all stars we ever see at night, so it will be obvious in the east at dusk.

Saturn is in the south at dawn.

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.

full-moon-21

Moon Phases in March 2015:

Full March 5, 12:05 pm
Last Quarter March 13, 12:48 pm
New March 20, 4:38 am
1st Quarter March 27, 2:43 am

Sunday, March 8, 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 5:45 pm on Friday, March 20, the Moon is directly overhead at the equator. This is therefore the vernal equinox. On this date everyone on Earth has the same amount of daylight and the same amount of night. The common statement that day equals night on this date would be true if the Sun were a point in our sky. Since the Sun is a disk about half a degree across in our sky, day is slightly longer than night on the equinox. For us, this is the ‘official’ start of spring; our days will continue to lengthen until the longest days of June usher in summertime. Below the equator, it is autumn, and days will continue to shorten until winter begins in June.

The New Moon of March 20 blocks the Sun, casting its shadow on the Earth. This results in a solar eclipse. Unfortunately, the shadow traces a path in the North Atlantic between Iceland and Scandinavia, making the eclipse inaccessible to us.

Click here for the full 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.