Archive for June, 2012
There are lots of viewing opportunities for the bright planets right now! We talked about Saturn just a couple weeks ago. It is still pairing nicely with Spica, just slowly shifting from above the southern horizon at dusk to the southwest and west and sinking lower towards the horizon as the evening wears on. As the summer progresses, the pair will appear further towards the west and lower towards the horizon at dusk. Here’s another picture of Saturn. This one is from 6-23-12 through our 8″ Meade LX-90 SCT with a clamp-on camera platform.
Mars still shines with a reddish hue above the southwest horizon after dark, though not as bright as it did in March as we continue to pull away from it. Don’t confuse it with the bright reddish star Arcturus higher in the sky. Mars will approach Saturn and Spica in August making a spectacular triplet of bright objects all with different colorings!
Mercury is rising higher above the west-northwest horizon as it approaches it’s greatest elongation at the end of this week. It never rises very far above the horizon so observation windows for Mercury don’t last very long. Try and catch it just after sunset in the next few days.
Are you missing the Jupiter and Venus show in the western sky from earlier this spring? Well, you can catch the rerun, but you’ll have to get up just before sunrise and look to the east-northeast to see the striking pair once again.
6:09 PM CDT today marks the northern solstice, it falls on the day with the longest daylight period of the year and marks the beginning of summer for the northern hemisphere. We traditionally refer to this point as the summer solstice but, in keeping with our efforts to become more global, northern solstice is the more proper term because it also falls on the day with the shortest daylight period of the year that marks beginning of winter for the southern hemisphere.
We’ve been tracking the apparent path of the Sun since December. On December 21 (the southern solstice) it was as far south of the celestial equator as it could be and subsequently started heading back towards the celestial equator which it crossed on March 20 (the March equinox). At 6:09 PM CDT today it will be as far north of the celestial equator as it can be. In the upcoming days it will start to head southward for its next rendezvous with the celestial equator in September (the September equinox). Of course, that means our daylight periods will start getting shorter.
Saturn is at its highest above the southern horizon just after sunset. It is easy to spot because it pairs very nicely with the bright star Spica almost directly below it. Look at the pair very carefully. Can you see that Saturn (the “top” star in the pair) has a slight yellowish color and Spica (the “bottom” star in the pair) has a slight bluish color?
Still can’t find the pair? Here’s another way: find the handle of the Big Dipper follow the arc of the handle (away from the dipper part) and soon you’ll arrive at a very bright star. This is Arcturus. Then keep following the arc and the next bright pair you arrive at is the Saturn/Spica pair. Remember the phrase “follow the arc to Arcturus and speed on down to Spica.”
If you get a chance be sure to view Saturn through a telescope; it never fails to disappoint even in a small scope. Here’s a picture I snapped on 5/13/12 through the Celestron NexStar 130 mm reflector:
Well, did you get to see the transit? We ended up having a nice event at UIU. The clouds were somewhat cooperative in that they did provide a nice break at the beginning, occasional breaks through the middle, and finally departed towards the end with about 30 minutes of really great viewing before sunset. We tried several techniques for viewing. The pinhole projectors made with two index cards were largely unsuccuessful with only a few pleople claiming to be able to see Venus. A welders mask with a #14 shade was very popular and those who tried it out could resolve the tiny black dot of Venus. Fortunately I was able to secure a full aperture solar filter for our Celestron NexStar 130 mm reflecting telescope.
The properly filtered telescope gave satisfying views and it was very interesting to compare the view through the telescope with the view through the welders mask because the telescope presents an inverted image. Here are a couple of the better pictures I took which have been beautifully cropped – thanks Kate!
The photo above shows the full disk of the Sun as seen through the filtered telescope. The black disk is Venus; the smaller, irregular dark spots are sunspots. Below again shows the Sun, not quite centered this time with some passing thin clouds.
All the photos I took at the event are available at the following link:
On Tuesday, June 5 people in the US will have the opportunity to view (provided skies are clear) a spectacular and rare astronomical event – the 2012 transit of Venus. Essentially what will happen is that the planet Venus will pass directly between the Earth and Sun. With proper viewing equipment (see below) Venus will appear as a small, black disk passing across the face of the Sun. The transit will continue until sunset. If you missed the 2004 transit of Venus, this is quite literally a once in a lifetime event. The next one won’t occur until the year 2117.
A few notes about viewing the transit: always use extreme caution when attempting to view the Sun. Everyone should note the following: looking directly at the Sun is extremely dangerous and is to be avoided. Using pinhole projection to view a projected image of the transit is the safest viewing method. #14 welders glass offers sufficient eye protection. Sunglasses do NOT offer sufficient eye protection. Telescopes and binoculars are absolutely not safe unless properly filtered with the correct solar filter accessory. There is much more information on the transit including more on eye safety and where else in the world it can be viewed at the following link:
In northeast Iowa the transit begins around 5:00 PM CDT and continues until sunset. The current forecast is for partly cloudy skies. I’m keeping my fingers crossed because my viewing luck has not been great lately. I struck out on both of the recent partial eclipses.
Most of the US will be treated to a partial lunar eclipse in the pre-dawn hours of Monday, June 4. For those of us in northeast Iowa it begins around 5:00 AM CDT. At it’s peak, about 40% of the Moon will be in the darkest part of Earth’s shadow, but the Moon will set for us before that occurs. Those further to the west will get a better show before the Moon sets. Also our current forecast is unfortunately calling for cloudy skies.
You may recall we had an annular solar eclipse on May 20 during new Moon. It’s not a coincidence that we have at least a partial lunar eclipse during the upcoming full Moon. Since the orbit of the Moon is tilted with respect to the plane of the Solar System lunar and solar eclipses are generally only possible a couple times per year when the Earth, Moon and Sun line up. Since the Moon orbits Earth relatively quickly the alignment often holds for a few weeks and lunar and solar eclipses generally occur in pairs as we are seeing currently.