Observing with Webb June 2010
Read about the events of the month, where the planets are, and what constellations you can see down below.
Special Question of the Month: My observant brother-in-law was wondering, "Why does the moon look like a "C" sometimes and a "U" other times?" Well, here goes...
Background information first - The ecliptic is an imaginary line on the sky that Sun traces out in the sky throughout the year (and day, sort of). The Moon also follows this path, roughly, meaning that sometimes it's a little above the line, sometimes a little bit below, and sometimes right in line (which is when eclipses occur). This ecliptic line changes angle throughout the year. In the winter, the line is much steeper at night (during the winter daytime it's lower - below the celestial equator, hence a lower sun angle and shorter days), whereas in the summer it's much less steep at night and higher during the daytime (sun is higher in the sky for a longer period of time). See the picture below. That's the simple answer. If you're asking yourself, "Well, why does the ecliptic path change angles?" then go here, or here for a more in-depth explanation.
Picture from http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question43.html
Have a question that you've always wondered about? Want to hear about a certain topic on the next podcast and in the next email? Send me a question either by replying to this email or sending me a message on podbean and I will include it next month.
EVENTS...
6th - Close Encounter - Moon and Jupiter - look SouthEast before sunrise, the Moon is 6° up and to the left of Jupiter.
11th - Close Encounter - Moon and Mercury - look East before sunrise, close to the horizon, the Moon is 6° to the left of Mercury.
New Moon - 12th (darkest skies)
14th - 15th - Close Encounter - Venus, Moon - Watch the sunset (in the WNW) and stick around afterward for some unique sightings:
15th - a very "young" and thin crescent moon will be 5° below Venus at sunset.
16th - The still young, but thicker, crescent moon will be 10° (one fist width) to the left of Venus.
16th - Close Encounter - Moon & Mars, Regulus (SW around sunset, W into the night - The three form an oddly shaped triangle)
19th - 20th - Close Encounter - Moon & Saturn - Look SW after sunset, W by midnight - Saturn will be about 9° above the Moon
20th - Extra Challenge! Venus will be less than a degree away from M44, the Beehive Cluster. Try seeing both of them through binoculars - Venus will be just above M44.
21st - Summer Solstice - The longest day of the year in the Northern Hemisphere. Technically summer starts at 7:28am this day, although meteorologically speaking it has already begun since the beginning of June.
Full Moon - 26th at 7:30am EDT Lunar Eclipse, but only visible in western North America and the Pacific
PLANETS...well, the ones visible with your naked eye
Planets you can see around Sunset - Venus (W), Mars (SW), Saturn (S)
Planets you can see throughout the night - Mars (WSWàW), Saturn (SWàW)
Planets you can see in the Morning - Jupiter (SE)
Mercury - Too close to the Sun (from our perspective) to be seen with the naked eye.
VENUS - Just look in the West about 2-3 fist width's above the horizon right after sunset and look for the VERY bright star that is up until 10pm. If you have binoculars or a telescope, watch as it gets a little bigger each day and closer to a half-Venus phase toward the end of the month. It's best to try this during the twilight because once it's dark, the brightness of Venus keeps you from seeing its phase. Close to the Moon on the 14th and 15th Extra Challenge! Venus will be less than a degree away from M44, one of the bright star clusters. Try seeing both of them through binoculars - Venus will be just above M44.
MARS - is already up in the SW (about 50° - 5 fist-widths) around sunset. It will move across the sky (from SW to W) throughout the night and set after midnight. If you can find Leo, look to the right of the backwards question mark dot for the red object that is Mars. Close to the Moon on the 16th and 17th.
Jupiter - About three fist-widths high in the SE at sunrise (before 6am) toward the beginning of the month, and gets higher every day. You'll only see it if you're an early riser with a great view of the eastern horizon. Close to the Moon on the 6th.
SATURN - Look to the S after sunset or SW around midnight until it sets around 2am. Extra Challenge! If you have binoculars or a telescope, see if you can see the rings of Saturn, They will be almost completely edge on, which will not happen again until 2025. For another decade, the rings will get much more inclined from our perspective. Close to the Moon on the 18th.
CONSTELLATIONS... (see sky map link at the bottom for a Star Map for this month - or ask Mr. Webb) Look straight up and you'll see...
Just after Sunset (around 8:30pm) - Bootes (The shepherder, kite, or ice cream cone). You can follow the arc of the Big Dipper's handle to get to its brightest star Arcturus.
Midnight - Hercules Extra Challenge! Look for M13, the Hercules Cluster in between two of Hercules' "keystone" stars. It known as the best globular cluster in the northern skies. It, like M3, will be a fuzzy spot in binoculars and will be even cooler through a telescope
Early Morning - Lyra, Cygnus, Lacerta - These are the Summer constellations, and since they are starting to rise in the morning now, that means that summer is on its way. Extra Challenge! Look for M57, the Ring Nebula in between two of Lyra's stars. It is 2,300 light years away, which means we're seeing what it looked like 2,300 years ago. The shell that you see is the remnants of the central star that blew up some 20,000 years ago. It has a donut-like appearance through a telescope. It'll be easy to find, but tough to see in binoculars, so get the scope out for this one.
GENERAL CONSTELLATION FINDING TIPS: No more winter constellations. But there are a few spring constellations that you can find.
Spring constellations: Bootes, Virgo, Leo, Corona Borealis, Hercules.
First find the Big Dipper in the North (a North Circumpolar Asterism that never sets) and look at the handle. Starting at the star closest to the "cup" part, follow the rest of the stars in the handle and follow the arc to Arcturus. Arcturus is the brightest star in Bootes the Shepherd. Some say he looks more like a kite, others say more like an ice cream cone.
Then, following the same "arc", speed on to Spica. Spica is the brightest star in Virgo. Virgo's a dimmer constellation, so you'll be rewarded when you find her.
To the left of Bootes is Corona Borealis. This is a small collection of stars that make a crown, cup, or U shape in the sky.
To the left of Corona Borealis is the great constellation of Hercules. Hercules is the Hero of the sky and has a central "keystone" asterism, in which lies M13, the Hercules Cluster.
Lastly, Leo is a constellation consisting of a backward question mark (or sickle) and a right triangle to the left. Use the two Big Dipper "cup" stars that are in the middle of the Big Dipper and follow the line they make to the bright star Regulus, the brightest star in Leo.
Use a sky map from www.skymaps.com to help you out.
A lot of credit for this information goes to:
SkyMaps.com - Download the monthly sky map here in many formats including Northern Hemisphere, Southern Hemisphere, and Equatorial
...and various sky programs such as Starry Night.
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