Planetary Aperçus: Featuring Saturn and Uranus

Spoken literally from the French, aperçu is an "outline or summary" or even a "glimpse," which is what this article will give you: an impression of two planets, although rather dim when viewed by the naked eye.

SATURN GOES RETROGRADE: FEBRUARY 8, 2012

This Wednesday, February 8, 2012, Saturn will begin to go retrograde. It rises around eleven pm to midnight, in the east, and reaches the zenith around 5 am. At that time, Saturn will be seen in Virgo, west of Spica (although it will vary among locations). Its retrograde period will signify better viewing, as it will rise earlier. "Saturn will be rising earlier each evening with each passing day. It’ll soon be in a more convenient place for evening viewing," EarthSky.com reminds. Saturn will be at magnitude 0.5, so spotting it shouldn't be that hard.

What is, precisely, retrograde motion? Covered in detail when Mars went retrograde in January 2012, apparent retrograde motion is the visible, backward orbit of a planet as viewed from earth, due to the orbit of that planet. On account of the fact that earth orbits quicker than other planets (particularly the outer planets; although the inner planets (Mercury and Venus) exhibit it rather differently), earth, from time to time, will "overtake" a planet of note (such as Saturn), causing that planet to look as if it travels in reverse, periodically being motionless for a few days before and after the event. As earth then passes the planet again, we can see that it resumes its old orbit (which is normal: west to east). [There is a visual at the Mars link above]

Saturn will be at opposition April 15, 2012. Opposition is literally when Saturn is closest to earth, and brightest in the sky, but until then, Saturn's retrograde is a spectacle! Early June marks the end of Saturn's retrograde motion. Read more about Saturn from EarthSky.com. From NakedEyePlanets.

URANUS AND VENUS CONJUNCT

So vibrant will be these two planets over the next few days. Venus has been shining strong, being the second brightest object in the night sky at magnitude -4.1 (although it will be brightest when the moon goes new), and now, just 0.3 degrees beneath it will be Uranus, bluish-green! Interesting to note, Uranus shines at magnitude 5.9, almost 10000 times dimmer than Venus!, and the brighter will lead you to the dimmer. Both planets are presently in Pisces.

First Quarter Moon Specialties: January 31, 2012

The moon is rather beautiful during the day, as it is rising about after 1 pm EST. Below is a galleria of pictures (from the greater Washington DC area) of the moon, which celebrate it being at first quarter today (January 31, 2012). Tonight, the moon will be encased in the night sky, with the planets, and you too can view them! The moon will be full on February 7, 2012, with planetary conjunctions swiftly approaching.

According to numbers placed below pictures, captions are as follows: 1) First Quarter Moon, taken on 1/31/12 at 1:37 pm EST. 2) The moon with an old cherry tree, taken 1/31/12 at 1:38 pm EST. 3) Moon with forest behind it, taken 1/31/12 at 1:38 pm EST. 4) The moon incarcerated between cherry-tree branches, taken 1/31/12 at 1:39 pm EST. 5) The moon is really at the zenith around 4:30 pm EST (same date as others). It is situated at the top of the picture, and the open sky and trees truly show its height! 6) Moon with cedar tree, taken 1/31/12 at 4:33 pm EST.

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Astronomical Events Calendar

Obscure Astronomical-Related Terms

Many words have been dedicated to the English language, and some to astronomy itself! We all know this as a fact, but some astronomy-related terms are lesser known than others, and this article is dedicated to them. In the first list, all words below are courtesy the Grandiloquent Dictionary. Definitions provided by them; copyright Grandiloquent Dictionary.

achluophobia -( ) A fear of darkness or of the night 

astrophobia -( ) The fear of stars 

barophobia - ( ) Fear of gravity

heliolater - ( ) A sun worshipper  

heliophobia - ( ) The fear of the Sun  

heliotropism - ( ) The tendency of plants to turn towards the sun  

hemeralopia - ( ) Only being able to see at night  

hemeraphonia - ( ) Able to speak only at night 

lygophobia - ( )A fear of darkness or of the night

myctophobia - ( )  A fear of darkness or of the night

nychthemeron - ( )  A period of 24-hours

phengophobia - ( ) The fear of the Sun or of sunlight 

raith - ( )  A quarter of a year 

scintillation - ( )  The twinkling of stars or small bursts of light 

selenocentric - ( )  One whose life revolves around the moon 

selenography - ( )  The science of geography of the moon 

selenomancy - ( ) Divination using the moon 

selenophobia - ( )  A fear of the moon

Below, more astronomical-related obscure terms are listed, although not necessarily from the Grandiloquent Dictionary.These are words from Dictionary.com and SeaSky Astronomical Dictionary.

Syzygy An alignment of three celestial objects, as the sun, the earth, and either the moon or a planet 

Azimuth the arc of the horizon measured clockwise from the south point, in astronomy, or from the north point, in navigation, to the point where a vertical circle through a given heavenly body intersects the horizon.

Ephemeris a table showing the positions of a heavenly body on a number of dates in a regular sequence.

Protoplanet the collection of matter, in the process of condensation, from which a planet is formed.

Zenith the point on the celestial sphere vertically above a given position or observer. 

Node either of the two points at which the orbit of a heavenly body intersects a given plane, especially the plane of the ecliptic or of the celestial equator. 

Facula an irregular, unusually bright patch on the sun's surface.

achrondite A stone meteorite that contains no chondrules.

Apastron the point at which the stars of a binary system are farthest apart (periastron).

Catena A series or chain of craters.

Ejecta Material from beneath the surface of a body such as a moon or planet that is ejected by an impact such as a meteor and distributed around the surface. Ejecta usually appear as a lighter color than the surrounding surface.

Granulation one of the small, short-lived features of the sun's surface that in the aggregate give it a mottled appearance when viewed with a telescope.

Hypergalaxy A system consisting of a spiral galaxy surrounded by several dwarf white galaxies, often ellipticals. Our galaxy and the Andromeda galaxy are examples of hypergalaxies.

Libration An effect caused by the apparent wobble of the Moon as it orbits the Earth. The Moon always keeps the same side toward the Earth, but due to libration, 59% of the Moon's surface can be seen over a period of time.

Nadir the point on the celestial sphere directly beneath a given position or observer and diametrically opposite the zenith.

Obliquity The angle between a body's equatorial plane and orbital plane.

Planemo A large planet or planetary body that does not orbit a star. Planemos instead wander cold and alone through the cosmos. It is believed that most planemos once orbited their mother star but were ejected from the star system by gravitational interaction with another massive object.

Events for the Week 8/6 to 8/13

Astronomy is back...please excuse no events last week...and her to stay! We have a multitude of exciting things happening in these coming weeks so stay tuned for them all! Beside stellar occultations and planetary conjunctions, it's just an ordinary week, with extraordinary astronomy finds.

Events for Saturday, August 6, 2011:

Tonight, the first-quarter moon lights the night sky in Libra, directly due-south after sunset and one-third of the way to the zenith. 7:08 am EDT is when the moon is at the fullest first-quarter possible, but the moon doesn't rise until approximately 2:15 pm, later that day. Our moon will appear more than half-lit, but this isn't uncommon, the moon's phases are unique - every one of them!

As you can see in the picture above, the moon just misses passing through the celestial gateway, as it will in 2014. The 'celestial gateway event' is a very rare event that occurs when the moon passes between the stars Zubenelgenubi and Zubeneschamali, or Alpha & Beta Librae. It's such a rare sight! Because of how much this celestial gateway is on the ecliptic, the moon may eclipse before this event in 2014? I don't know...just a comment.

Events for Sunday, August 7, 2011: 

The moon shines around Antares, near the head of Scorpius, this night. But, enough of the moon! Don't we see it every night - try watching something else, like Pluto. Pluto reached opposition last June, so the peak time for observation is over, but you can still manage to see it with your telescope (10+ inch). It will conjunct this week with star Y Sagittarii, just passing 0.1 degrees south of it, making spotting Pluto a step up. If you have an extremely strong telescope, try viewing Pluto's new moon?

So, if you don't have a telescope wider than 10 inches, try searching for stars in the sky, and familiarize yourself with the constellations. Constellation guide. Also try downloading astronomy programs like Celestia, Stellarium, etc.

Events for Monday, August 8, 2011

Before the sun rises (4 am): The east-northeast sky brings us Mars, glowing at magnitude 1.4 in western Gemini. (Mars has moved a lot since it was in Taurus last). Be careful not to confuse it with surrounding stars. This week, try not to locate Betelgeuse (star in Orion about fifteen degrees to the lower right of Mars) and say you've found Mars."This morning, Mars lies slightly more than 1° north of 3rd-magnitude Eta (η) Geminorum. On Thursday morning, the planet slides a similar distance north of 3rd-magnitude Mu (μ) Gem." (Astronomy.com)

After the sun sets: You too can still view asteroid 4 Vesta! Opposition occurred the 5 of August, but you can still see the protoplanet. What about Dawn? If you have a strong enough telescope, look away! (Don't forget Ceres as well...)

Vesta, as seen by Dawn

Events for Tuesday, August 9, 2011:

As we return to the beautiful mini-solar system of Jupiter, watch out! Ganymede will eclipse around 3:24 am, with the transit of the Great Red Spot later, at 4:08 am.  Ganymede, Jupiter's biggest satellite, will disappear into eclipse by Jupiter's shadow around 3:24 a.m. Detailed list of Jovian Phenomena here, just click 'now' for most recent events.

Simulation of Jupiter's moons, August 10, 2011 at 00:00 UT; l-r, Callisto, Europa, Io, Ganymede

Events for Wednesday, August 10, 2011:

"In late afternoon or early evening, the dark edge of the gibbous moon occults the 2.9-magnitude star Pi Sagittarii (in the Teaspoon) for the eastern half of North America." (Sky&Telescope). Make sure to see our article! (Will be published August 8, 2011). Also, it may be best to view the Perseid meteor shower this morning. The Perseids are here!

A Perseid in 2009

Events for Thursday, August 11, 2011:

The beautiful Big Dipper shines north tonight, with Polaris at straight north. If you can manage, try looking for Cassiopeia farther northeast, abut the same height as the big dipper. (Persieds peak tonight).

Credit: Akira Fujii

Events for Friday, August 12, 2011:

The Persieds keep oncoming strong...so watch out for them!

Events for Saturday, August 13, 2011

Tonight the full moon will shine upon the earth, at 2:57 pm EDT. It will between Aquarius and Capricornus.

Solar System Calendar

06 Aug 2011 11:08:19 First Quarter
07 Aug 2011 04:46:57 Max. South Declination of Mars, 23.7°
07 Aug 2011 08:47:24 Min. South Declination of Mercury, 7.1°
08 Aug 2011 23:19:55 Min. North Declination of the Moon, -23.2°
09 Aug 2011 06:34:41 Ascending Knot Passage of the Moon
09 Aug 2011 08:50:08 Perihelion of Venus, 0.71846 AU from Sun
12 Aug 2011 13:48:13 Conjunction of Pallas with the Moon, 32.7°
12 Aug 2011 23:00:46 Conjunction of Vesta with the Moon, 10.5°
13 Aug 2011 00:08:31 Min. North Latitude of Mercury, -4.8°
13 Aug 2011 08:48:35 Farthest Distance of Venus, 1.73085 AU from Earth
13 Aug 2011 18:55:31 Closest Approach of Mercury, 0.60525 AU from Earth
13 Aug 2011 18:57:32 Full Moon

Planet Viewing

I have located a wonderful resource for viewing the planets and other events in August 2011. Here is the link - it has it all. I highly recommend spending time to look at this.

Have a great viewing this week!