Summer is in full swing.  June’s weather was just as one would have expected, at times hot and humid, at other times cool and rainy.  Let's see what the short, night hours of this July will bring.

As evening twilight darkens, look to the west for some glimpses of Saturn, Mars, and, near the end of the month, Venus.  Jupiter reaches opposition as it moves through nighttime southern skies all month long.  Mercury has a pretty good apparition in early morning skies in early July.

Take a few minutes before you begin your journey through July skies and go get your star map.  It is in PDF format which nearly everyone can use and print.  These starmaps can be found at the SkyMaps.com webpage.  Click this link and choose the PDF skymap for the Northern Hemisphere for July 2008.  Download and then print it out.  It's a 2-sided page with a skymap and almanac on the front and a reference sheet of visible objects on the back.  I usually print page 1 only, place that page back in my printer in the correct way, and then print page 2 only.  That way I have a single sheet with all the information I need for the month.  Now you're ready to explore the skies of July!

Centered along the southern horizon is our featured constellation of the month, Scorpius.  This constellation boasts as many third magnitude or brighter stars within its borders, 13 in all, as any other constellation visible from mid-northern latitudes.  These stars should appear bright enough to be seen even in the fairly bright environments found in small towns.  From downtown Rochester, a clear southern horizon might allow you to just barely spot a few of them.  Not too surprisingly, 9 of the 13 stars are fairly close to us, between 450 and 600 light years away.  Many of the bright stars we see are actually members of a large open cluster of stars that is moving through space as a group.  Also in this part of the sky we see the brightest parts of our Milky Way galaxy.  Many beautiful gas clouds and star clusters lie in the ‘tail’ of the Scorpion.

There’s a lesson to be learned by looking at stars and their apparent brightness.  Two stars that look similar in brightness may be at tremendously different distances and therefore have tremendously different true brightnesses.  A good case to illustrate this can be found using two stars of the famous Summer Triangle.  The Triangle, now high in the southeastern sky after twilight fades, is made up of Vega, Altair, and Deneb.  To the eye, Altair appears to shine just a little brighter than Deneb.  Looks are deceiving!  Deneb is some 100 times as far away (1600 light years) and 10,000 times brighter!  If Deneb could be placed at the same distance as Altair (17 light years), it would shine as brightly as the first quarter moon at magnitude -9!  Deneb gives off as much light in one summer night as our Sun gives off in an entire century!  And what about Vega, the star that looks the brightest?  It happens to be the most luminous star in the sky that is within 35 light years (it's 25 light years away).

Western skies have the fading spring constellations, and so, except for Arcturus and Spica, there aren’t too many bright stars in this half of the sky.  The Big Dipper appears in the northwest with its handle pointed almost straight up.  To the northeast, Cassiopeia appears as a “W” shape.  It seems that the areas of greatest interest lie in the middle third of the southern to southeastern sky.  Use the Milky Way in Scorpius to locate other bright constellations.  As you move from the southern to northern horizon, Sagittarius, Aquila, Cygnus, and Cassiopeia all fall in line.  Ophiuchus, Hercules, Lyra, and Cepheus then can be found along the boundaries.

Constellation of the Month
Scorpio is the featured constellation this month.  Scorpio is the Scorpion that stung Orion.  The scorpion has a shape that even those people with little or no imagination can see.  Located near the brightest part of the Milky Way, it sits low on the horizon and it appears the creature is being punished by having boiling water poured on it from the Teapot of Sagittarius, just to its east.  We see the “steam” as the Milky Way.

In Greek mythology, Scorpio is involved with Orion.  It seems that Orion boasted that he was the greatest hunter of all.  Hera (Zeus’ wife) heard this and was extremely angry (jealous?) and so sent the poisonous scorpion to sting and kill him.  Orion fought with the scorpion for many days and nights without success.  When the weary Orion wasn’t looking, the scorpion struck and stung the mighty hunter to death.  Zeus took pity and placed him in the heavens as the mighty hunter of the winter skies.  Hera placed the scorpion in the heavens at the opposite side of the sky, so even now, Orion tries to avoid the creature by not being visible until his killer is completely below the horizon.

Within the borders of Scorpius are several beautiful deep-sky objects.  On the star map that the link above points to, many of these are identified with their Messier numbers.  Binoculars are a great way to explore the many star clusters and gas clouds found in the area of the sky.  Sit back sometime in a comfortable chair and slowly scan the southern horizon near Scorpius.  Follow the tail downward to Zeta Scorpii, just before the tail curves eastward.  Zeta is a beautiful double star and lying just above it are two open clusters, NGC6231 and Trumpler 24.  To many, this area appears as a false comet, with a fan-shaped tail pointed upward.  Now continue eastward in the tail of the scorpion to find two more, wonderful open clusters, including M6 and M7.

Now, move back to Antares.  Look just to the right and slightly below Antares and see if you can spot M4.  It will appear as a faint, fuzzy object.  Only a telescope will show the individual stars making up the cluster.  Next, place Antares in the lower left corner of your binocular field.  Rho Ophiuchi should now be visible near the center (or just to the upper right of center).  (Rho is just to the left of M80 on the star chart.)  Close inspection will show this star to be a triple star system.  Last, check the area above Antares and to the left of Rho.  You should notice a marked decrease in the number of dim stars visible.  You are looking in the direction of one of the many dark clouds between our planet and the center of the galaxy.  These dark clouds are made of the material that many astronomers believe is more abundant in the universe than the material we can see!
 

The Planets

Mercury reaches greatest elongation west of the Sun on the 1st.  This is the middle of the best time to spot this illusive planet, this time in morning skies.  It will continue to rise over an hour before the Sun until about mid-month, when it begins to quickly move back toward the Sun.  So quick is its motion that it reaches superior conjunction on the far side of the Sun on the 29th.

Venus ever so slowly makes its appearance in evening skies.  At the time of superior conjunctions, Venus' motion relative to the Earth and Sun appears to be the slowest.  It won't be until late July and early August that the gibbous appearing planet will make its way far enough into evening skies to be easily visible.

Mars is high in western skies after sunset.  It stays close to Regulus and Saturn all month long.  In fact, during the day on the 1st, it makes the closest approach of any planet to a 1st magnitude star for the entire year.  Along with Saturn nearby, this will be a great time for a photograph of that area of the sk. 

Jupiter is above the south-southeast horizon as skies darken, above the stars of Sagittarius.  It reaches opposition with the Sun, rising as the sun sets, on the 9th.  That means it will be visible all night long. Unfortunately, Jupiter is fairly low in the sky during this viewing season, making turbulence near the horizon an important consideration when trying to see details in the clouds.  Hazy, humid nights are often the best for planetary viewing.  We'll likely get a few of those in July!

Saturn is near Mars and Regulus as July opens.  On the 10th, watch as these 2 planets are only about 1 degree apart.

Neptune, at magnitude 8, and Uranus, at magnitude 6, are easier objects to find as they rise near midnight on July 1st.  Still, a star chart is needed to help find these planets in an area of the sky with few bright stars to help in locating dim objects.

Jupiter and Saturn

The number of events involving Jupiter’s Galilean moons and Red Spot is beginning to decrease as Jupiter sets earlier each night.  The Date and Time are in the first two columns, while the last column gives the event using the following abbreviations:
Ec - moon eclipsed by Jupiter's shadow                     Oc - moon blocked by disk of Jupiter
Sh - shadow of the moon on planet                            Tr - moon itself in front of planet
I - ingress, the start of the event                                  E - egress, the end of the event
D - disappearance                                                     R - reappearance

 

The Moon
 

New Moon occurs on the 2nd at 10:19 p.m. and marks the start of lunation 1058.  Watch as the thin crescent moon is just east of the Saturn-Mars-Regulus trio on the evening of the 6th. 

First Quarter Moon occurs on the 10th at 12:34 a.m.  It is near Spica that evening.  The waxing gibbous moon can be seen approaching Antares on the evening of the 13th.  It is south of Jupiter on the 17th.

The Full Moon of July is called the Buck or Thunder Moon.  This year it occurs at 3:59 a.m. on the 18th.  The moon is near Neptune on the morning of the 20th and is well north of Uranus on the 22nd.

Last Quarter Moon occurs at 2:42 p.m. on the 25th.  The waning crescent moon passes near the Pleiades star cluster just after noon on the 27th.

Special Events

Wednesday, July 2nd marks the midpoint of the year 2008.  It doesn’t seem possible that this year is already half over! 

On July 4th at 4 a.m., the Earth reaches aphelion, the point in its yearly orbit when it is farthest from the Sun.  Yes, farthest.  We have summer because of the tilt of the Earth on its axis, not because of distance to the Sun.  Besides, we’re only about 5 million kilometers (3.4%) farther from the Sun now than we were on January 4th when we were at perihelion.  By the way, the date of aphelion can vary from 4 p.m. on the 2nd to about 8 p.m. on the 6th.  This year the farthest point lies 152,097,000 km from the Sun.  

Solar activity has been nearly non-existent over the past several months.  The next solar cycle, number 24, was supposed to start in late 2007 and is quite a bit overdue.  This may have implications for our climate - solar activity drives everything from temperatures to ocean currents.  Try this sight, http://www.spaceweather.com, and you'll get the latest information on any new solar activity.
 

Space Missions
 

On May 25th, the Phoenix Polar lander touched down safely near the north pole of Mars.  For the next 3 months (Mars' northern hemisphere summer begins on June 24th) this lander will investigate this cold environment looking for signs of ice beneath the soils.  Early findings seem to show ice very close to the surface.  Check the website for all the latest information.

Messenger
This spacecraft recently completed a close fly-by of Mercury and took hundreds of images of the part of Mercury not imaged in the 1970's (Mariner 10, 1974 and 1975).  This flyby adjusted the orbit slightly so that the spacecraft can flyby Mercury twice more ( Oct. 6, 2008 and Sept. 29, 2009) before entering orbit on March 3, 2011.

Mars Reconnaissance Orbiter
Right now, the most interesting news from Mars is coming from a spacecraft called the Mars Reconnaissance Orbiter.  The spacecraft is now in its operational orbit, achieved earlier this Fall.  From this orbit, the spacecraft is taking high resolution pictures and other measurements.  Pictures are already being sent back from the spacecraft that are among the best ever taken from orbit around Mars.  One even shows one of the Mars Rovers sitting at the edge of a large crater!   Amazing technology.  And sometime this month, Opportunity is going to be driven down into Victoria Crater.  It will use a gradual sloping area called "Duck Bay" to drive into the crater.  Scientists are hopeful they will find many layered rocks to explore within this crater and are willing to take the chance that Opportunity may not be able to climb back out should one of its 6 motorized wheels fail while in the crater. 

Mars Global Surveyor
The Mars Global Surveyor has fallen silent.  Last November, something happened that caused the spacecraft to go into safe mode.  After that initial communication, nothing more has been heard from the spacecraft.  Speculation is that one or more of its solar panels have failed thus shutting down all the electrical systems.  Launched on November 7, 1996 MGS achieved orbit around Mars on September 11, 1997.  Over those last 9+ years, the spacecraft has returned more than 240,000 images and untold megabytes about the environment of the Martian surface and atmosphere.

Mars Rovers
The two American Mars explorers, Opportunity and Spirit, are still functioning fairly well and returning amazing data from Mars!  Both are well over TWO years of operation on the surface of Mars.   One rover, Opportunity, is now on the rim of Victoria Crater.  From that location it has spent much time taking very detailed images of the crater walls.  It has started to travel around the crater looking for more targets to image as well as a way into and out of this crater.  Engineers want to get a closer look at the interior of the crater, but would rather do so fully expecting to be able to drive out later.  Even so, there is some thought being given to the idea of driving into the crater for those detailed studies even if it means not being able to get back out - basically sacrificing the Rover for this important study.  Latest news.....  !!

A solar mission that continues to produce results is the STEREO solar mission.  STEREO consists of two space-based observatories - one ahead of Earth in its orbit, the other trailing behind. With this new pair of viewpoints, scientist will be able to see the structure and evolution of solar storms as they blast from the Sun and move out through space. 
 

Another solar spacecraft, Hinode, an international space effort, continues its studies of our nearest star in stunning detail.  Hinode is Japanese for sunrise. 

Venus Express
The European Space Agency placed a spacecraft in orbit around Venus in April.  Since then the spacecraft has been slowly adjusting its orbit.  Scientific data about this cloud covered planet is now being returned.

Cassini mission to Saturn    
Now in orbit around Saturn!  This spacecraft is sending back amazing pictures.  Recent images of Titan have shown methane lakes!

Stardust
On January 15, 2006, after more than 7 years and billions of miles of travel through space, the Stardust spacecraft returned to Earth with some precious cargo -- pristine samples of comet and interstellar dust. Stardust will provide the world's first opportunity to analyze preserved samples of the fundamental building blocks of our Solar System that formed 4.6 billion years ago.  Analysis will begin soon as materials are distributed to various labs throughout the world for study. During a brief but daring encounter with Comet Wild 2 on January 2, 2004, Stardust captured thousands of particles and began its arduous two-year journey back to Earth, where its Sample Return Capsule (SRC) landed in the Utah Test and Training Range (UTTR) within the Great Salt Lake Desert.

New Horizons
Next up for NASA and the Johns Hopkins Applied Science Lab is the mission of the New Horizons spacecraft to Pluto.  After a couple of days of delays, the mission started with a spectacular launch on January 19th.  Even with launch this year and being given the greatest velocity ever given to a spacecraft during launch, New Horizons won't reach Pluto until 2015.  Just the other day, the spacecraft sent back a starfield used for calibration in which Pluto could be seen.  Of course, it was just a dim pinpoint of light, but the spacecraft is operating exactly as it should be at this time.

A mission, not well-publicized, may not have had the success hoped for.  A Japanese spacecraft called Hayabusa flew in formation with a tiny asteroid called Itokawa last September.  In late November, the spacecraft was successful in making a soft landing on the asteroid.  This success came after one attempt failed.  Japanese scientists believe at the time that the spacecraft was able to gather up material from that landing location.  This may not have occurred.  Another task, to leave a small, automated lander, was not successful.  The spacecraft backed away from the asteroid a small distance and went into safe mode after it detected a problem with a control jet.  Recently, Japanese scientists have been able to regain communication with the spacecraft.  The hope to turn on the ion engines early next year and have the spacecraft return to the earth in 2010.

Deep Impact
Performed as advertised and delivered an impactor into the Comet Tempel 1.  The results were dramatic as the impactor and flyby mother craft both recorded fine detail in the comet and the resulting ejecta cloud.  Check this web page for all the latest results and images.

European Space Agency's Huygens web site.
Archived information about the Huygen's probe which landed on Titan.

Mars Express
This European Space Agency craft continues to send back images using a high resolution camera.  

SIRTF
Space Infrared Telescope Facility:  Go to this website and search for NGC7331.  The image you find is of a galaxy many astronomers feel looks just like our Milky Way galaxy would look from 50 million light years!

2001 Mars Odyssey
Mapping the surface of Mars.  

Latest Images from Mars Odyssey

SOHO
Here you can find the latest images and information on the Sun.