Go Stargazing! May Edition

Saturn is the only planet in May 2011 evening skies.  Face south southeast at dusk, and you’ll see Saturn near a star of similar brightness— Spica in Virgo.  Saturn is significantly higher in the sky than Spica and a bit to its right as you face south.  Last month, Earth passed between the Sun and Saturn.  That alignment, called opposition, put Saturn in the sky all night long.  The ringed planet is now well placed for evening viewing, and remains in the evening sky until late September 2011.

mars-06-crop
Mars
Creative Commons License photo credit: chipdatajeffb

The other four naked eye planets are involved in a very close gathering low in the east at dawn.  You will need a clear view all the way to the east northeastern horizon at daybreak to observe this planet massing.  However, the planets do outshine all stars in this general area. If you’re able to observe any points of light just above the horizon as dawn begins, you’re probably seeing the planets.  As of now, Venus and Mercury rise first, with Mercury about a degree under the brighter Venus.  Mars and Jupiter are a bit to their lower left, with Mars a little to the left of Jupiter.  Mars was less that half a degree above Jupiter on May 1, and is now slowly pulling away from it.  Venus and Mercury are moving faster, so they are closing the gap on Mars and Jupiter.

On the morning of May 11, Venus and Mercury will be aligned with Jupiter, with Venus less than one degree from Jupiter.  This is also when the entire grouping is the most compact, with all four planets within six degrees of one another.  By May 21, Mercury and Venus will have caught up with Mars, with Venus just over a degree from the red planet.  After this, Mercury and Venus pull ahead of Mars and thus go deeper into the sun’s glare.  Mars and Jupiter, left behind, remain in the morning sky all summer.

Star Gazing
Creative Commons License photo credit: jurvetson

A swath of brilliant winter stars sets in the west at dusk this month.  Orion, the Hunter, is still visible in the west as May begins.  His two dogs, represented by Sirius and Procyon, are to his left.  To Orion’s right is Taurus, the Bull, with the star Aldebaran as its eye. Gemini, the Twins, are above Orion.  The Big Dipper is above the North Star, with its handle pointing to the right.  From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica;’ those stars are in the east and southeast at dusk.  Leo, the Lion, passes almost overhead in late evening.

As Orion and Taurus set, look for Antares, brightest star of Scorpius, the Scorpion, to rise in the southeast.  At the same time, Vega, brightest star of the Summer Triangle, appears low in the northeast.  These stars remind us that summer is on the way.

Moon Phases in May 2011:

New Moon                              May 3, 1:50 a.m.

1st Quarter                             May 10, 3:32 p.m.

Full Moon                               May 17, 6:07 a.m.

Last Quarter                          May 24, 1:51 p.m.

Go Stargazing: April Edition

Saturn dominates April 2011 skies because yesterday, on April 3, the Earth passed 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.

Venus’ apparition as a dazzling morning star is coming to an end.  It is getting lower and lower in the sky each morning as the angle between the solar system plane and the horizon gets shallower.  Face southeast at dawn, and you can’t miss it of you have a clear horizon.

Jupiter is directly behind the sun from our perspective on April 6 and therefore invisible all month.

Mars also remains lost in the sun’s glare all month.

A swath of brilliant winter stars continues to dominate evening skies.  These stars are now high in the west at dusk and set in late evening.  Orion, the Hunter, is in the southwest as April begins.  His two dogs, represented by Sirius and Procyon, are to his left.  Beside Orion in the west is Taurus, the Bull with Aldebaran as its eye. Gemini, the Twins, are above Orion.  The Big Dipper is to the upper right of the North Star, with its handle pointing down and to the right.  From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are low in the east at dusk.  Leo, the Lion, passes almost overhead in late evening.

Below Sirius, just above the southern horizon in late twilight, 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.  In early April, you can still see it in the evening just after dusk.

Lune
Creative Commons License photo credit: ComputerHotline

Moon Phases in April 2011:

New Moon                      April 3, 9:32 a.m.

1st Quarter                     April 11, 7:05 a.m.

Full Moon                       April 17, 9:43 p.m.

Last Quarter                  April 24, 9:46 p.m.

Sunday, April 24, is the first Sunday after the first Full Moon of spring.  Therefore, this is Easter Sunday.  This happens to be the second latest possible date for Easter.  Easter will fall on April 25, the absolute latest date, in 2038.

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!

Go Stargazing! July Edition

During July, you can watch a great planet race, as Venus closes in on Mars while they both close in on Saturn!

Saturn is now in the south southwest at dusk.  Look just to the west of due south, about 2/3 of the way up from the horizon to the zenith.

Venus remains high in the evening sky during July.  Face west at dusk and look for a point of light that outshines everything in the sky but the Sun and the Moon.

Mars is also in the western sky.  Look in the west at dusk for a reddish point of light between Venus and Saturn.

Observe all three carefully throughout July and watch as they get closer together.  By July 31, Mars will have caught up to Saturn, with Venus only about 7.5 degrees away.  Keep watching next month as Mars moves ahead of Saturn and Venus passes them both.

Jupiter is in the south at dawn this month.  It outshines all stars in the sky, so it’s easy to find.  By July 31, Jupiter rises at about 11 p.m.; it will be a late evening object next month.

In the west, a distinct backwards question mark shape outlines the mane and forepaws of Leo, the Lion.  Three stars forming a right triangle are to its upper left; they mark Leo’s hindquarters.  This month, the Lion serves as the backdrop for the great planet race described above.  The Big Dipper is high in the northwest at dusk. You can extend the curve of its handle to ‘arc to Arcturus’ and then ‘speed on to Spica.’  These stars high in the west and southwest, respectively, by dusk tonight.  Arcturus, by the way, is the fourth brightest star we ever see at night, but the brightest one Americans ever see in all of July.

In the east, look for the enormous Summer Triangle, consisting of the stars Deneb, Vega, and Altair.   This triangle is up all night long in July, hence its name.  Scorpius, the Scorpion, is in the southeast at dusk.  Sagittarius, the Archer, known for its ‘teapot’ asterism, is to its left.  Between these two star patterns is the center of our Milky Way—the brightest part of that band as wee see it.  On a cloudless night far from the big city, see if you notice the Milky Way glow near the ‘teapot’ of Sagittarius.

Summer Triangle

Moon Phases in July 2010:

Last Quarter                       July 4, 9:36 am

New Moon                            July 11, 2:40 pm

1st Quarter                         July 18, 5:11 am

Full Moon                            July 25, 8:36 pm

Flag of Turkey
Creative Commons License photo credit: steelight

The new moon of Sunday, July 11, will align precisely with the sun and Earth, casting its shadow on the Earth.  This will cause a total solar eclipse.

Unfortunately, the shadow’s path is entirely over the South Pacific Ocean.  Easter Island and certain islands of French Polynesia are the only land where totality can be seen.  Even partial phases are visible only from South America.

On Tuesday, July 6, Earth is as far from the sun as it will get this year, a position called aphelion.  Remember, the Earth’s orbit is not quite a circle but an ellipse.  We are therefore slightly closer to the Sun in January than in July.  Also, remember that the difference between our January and July distances from the Sun is small.  When it comes to making us hotter or colder, the effect of our axial tilt dominates.