Seeing Stars with James Wooten: The Stars of Summer are Here

The Summer Triangle is high in the east.  This consists of the brightest stars in Cygnus, Lyra, and Aquila.  Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius to his left.  Leo, the Lion, sets in the west.  From the Big Dipper’s handle, ‘arc to Arcturus’ and ‘speed on to Spica’ in the southwest.  Venus now moves away from Jupiter as they both gradually become lost in the Sun’s glare

The Summer Triangle is high in the east. This consists of the brightest stars in Cygnus, Lyra, and Aquila. Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius to his left. Leo, the Lion, sets in the west. From the Big Dipper’s handle, ‘arc to Arcturus’ and ‘speed on to Spica’ in the southwest. Venus now moves away from Jupiter as they both gradually become lost in the Sun’s glare

This is the last month to observe the two brightest planets in the western evening sky. On June 30, Venus overtook Jupiter. This month, watch Venus shift to the left of Jupiter each evening at dusk. Meanwhile, both planets appear lower and lower to the horizon each night, until they are both lost in the Sun’s glare by the end of the month. At dusk, look over the point of sunset for the brightest objects there; Venus and Jupiter outshine everything but the Sun and the Moon.

Saturn is now in the southern sky at dusk. Although it is not as brilliant as Venus or Jupiter, it outshines the stars around it, so it’s also easy to see.

Mars remains lost in the glare of the Sun.

The Big Dipper is above and left of the North Star, with its handle pointing up. From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are in the southwest at dusk. Leo, the Lion, sets in the west at dusk.

Antares, brightest star of Scorpius, the Scorpion, is in the southeast, with the ‘teapot’ of Sagittarius rising behind it. Saturn is right above the scorpion’s head. The Summer Triangle has fully risen in the northeast. The stars of summer are here.

full-moon-2

Moon Phases in July 2015:

Full July 1, 9:20 pm; July 31, 5:43 am
Last Quarter July 8, 3:24 pm
New July 15, 8:24 pm
1st Quarter July 23, 11:04 pm

At 2:41 pm on Monday, July 6, Earth is as far from the Sun as it will get this year, a moment known as aphelion. Remember, though, that the difference between aphelion and perihelion (in January) is small (only about 3%). Earth’s 23.5 degree tilt on its axis is a much more important effect. That’s why we have all this miserable heat and humidity now, rather than in January.

Just before 6:50 am CDT on Tuesday, July 14, the New Horizons spacecraft makes its closest approach to Pluto. As this is our first opportunity ever to gather real data from Pluto and its moons, astronomers are quite excited. The craft is already close enough to take some pictures, which you can see here. The Museum will have special activities for this occasion; email me if you want more information.

The Full Moon of July 31 is the second one of the month. That’s one of the definitions of a Blue Moon.

Planetarium Schedule:

Brazos Bend State Park, where our George Observatory is sited, has been closed since May 27 because the rains of Memorial Day and of Tropical Storm Bill caused the Brazos to overflow. The park plans to reopen on a limited basis July 8, making July 11 the first Saturday available for public observing.

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. I generally do one such tour on short June evenings.

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.

Go Stargazing! July Edition

Saturn is the only planet visible to the naked eye in the evening skies of July, 2011.  Face south-southwest at dusk, and you’ll see Saturn near a star of similar brightness—Spica in Virgo.  Saturn is a bit to the right of Spica as you face southwest.   The ringed planet remains well placed for evening viewing, and remains in the evening sky until late September 2011.

Hubble Images Suggest Rogue Asteroid Smacked Jupiter
Creative Commons License photo credit: NASA Goddard Photo and Video

Mars and Jupiter are now higher in the pre-dawn sky.  Jupiter, set against a background of very dim stars, dominates the eastern sky at dawn.  Mars is dimmer and much lower in the east northeast.  It has fully emerged from the sun’s glare, and will brighten slightly each morning.  Venus is now out of sight, as it is passing around the far side of the sun from our perspective.

The Big Dipper is above the North Star, with its handle pointing up.  From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are in the southwest at dusk.  Leo, the Lion, sets in the west at dusk.

Antares, brightest star of Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius rising behind it.  The Summer Triangle has fully risen in the northeast.  The stars of summer now dominate the evening sky.

Moon Phases in July 2011:

New Moon                       July 1, 4:02 p.m.

1st Quarter                     July 8, 9:09 p.m.

Full Moon                        July 15, 3:12 p.m.

Last Quarter                  July 23, 6:48 a.m.

Winter Solstice Lunar Eclipse
Creative Commons License photo credit: Bruce McKay~YSP

The new moon of July 1 partially blocks the sun, but only as seen from the Antarctic.  No one will get to see a total eclipse because the moon’s full shadow, or umbra, passes just below the Earth.

As we celebrate our independence this July 4, Earth will be at aphelion (at its greatest distance from the sun).  The precise time is 10 a.m.  Perihelion, the Earth’s closest approach to the sun, occurs in January.  Earth has perihelion and aphelion because its orbit is not a circle but an ellipse with an eccentricity (out-of-roundness) of about 1.6%.  Such a small variation, however, exerts no significant influence on our seasons, as you can determine for yourself by stepping outside.  The 23.5 degree tilt of Earth’s axis, on the other hand, is a much more dominant effect.  The very high midday sun of July ensures long days and baking heat in Houston and across much of the Northern Hemisphere.

By popular demand, our George Observatory will open to the public Fridays and Saturdays this summer (except July 8, due to a prior booking).  The Discovery Dome, our traveling planetarium, will be set up each of these Fridays to show films throughout the evening.

Go Stargazing! March Edition

Hubble Images Suggest Rogue Asteroid Smacked Jupiter
Creative Commons License photo credit:
NASA Goddard Photo and Video

Jupiter leaves the evening sky this month.  For now, you can still observe it in the west at dusk, where it sets by 8:25 on March 1.  It outshines all stars in the sky, so it’s easy to find.  Face west at dusk and look for the brightest thing there.  However, Jupiter is getting a little lower in the sky each evening.  You should be able to follow it until about the middle of the month.  By month’s end, Jupiter is lost in the sun’s glare.  On April 6, it is directly behind the sun from our perspective.

Mercury emerges from behind the sun this month and appears beside Jupiter before Jupiter fades from view.  On March 15, Mercury is about two degrees to the right of Jupiter as they both set in twilight.  As Jupiter becomes lost in the sun’s glare, Mercury remains visible low in the west at dusk for the rest of the month.

Venus remains a dazzling morning star.  It is getting lower in the sky as the angle between the solar system plane and the horizon gets shallower.  Face southeast at dawn, and you can’t miss it.

Saturn is in the southwest at dawn, getting lower in the southwest by month’s end.  This is because at the end of the month, Earth is about to pass between the sun and Saturn.  This alignment, called opposition, puts Saturn in the sky all night long; it rises in the east at dusk and sets in the west at dawn (the precise opposition date is April 3).  As a result, Saturn is also an evening object, rising in the east by 9:00 p.m. on March 1 and by dusk on the 31.

Mars, just past conjunction with the sun, remains lost in the sun’s glare all month.

A swath of brilliant winter stars continues to dominate evening skies.  These stars are now due south at dusk, but shift to the southwest later in the evening.  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, rises in the east.  The Big Dipper has now fully re-entered the evening sky; it is to the right of the North Star with the handle pointing down.

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.  March and March are the best months to see it in the evening.

Moon Phases in March 2011:

New Moon                              March 4, 2:46 p.m.

1st Quarter                             March 12, 5:45 p.m.

Full Moon                               March 19, 1:10 p.m.

Last Quarter                          March 26, 7:07 a.m.

At 6:21 p.m. CDT on Sunday, March 20, the sun is overhead at the Earth’s equator, giving everyone in the world the same amount of daylight.  This, then is the vernal equinox, the ‘official’ start of spring.  For us, days have been lengthening since December 21; by now daytime is almost as long as the night.  After March 20, daytime is longer than night for us.  For many people, however, wintry weather continues so long as arctic air masses remain in motion across North America, Europe, and Asia.

Winter time
Creative Commons License photo credit: cvanstane

People in the Southern Hemisphere had their longest days back in December; their days have since shortened to be about equal to the night.  After March 20, night is longer than day down there, so this is their autumnal (fall) equinox.

Sunday, March 13, is the second Sunday in March.  Therefore, Daylight Saving Time begins at 2 that morning (1:59:59 is followed by 3:00:00).  Don’t forget to set your clocks forward one hour on Saturday night, March 12!