3 Mornings With the ISS

   A favorite pastime of mine is to watch the International Space Station orbit over my part of the world and when possible capture the flyover on film.
   This picture is from Wednesday September 21st and is a time lapse consisting of about 80 separate pictures stacked together and processed as one picture.
    The dashed line is the reflected light from the ISS and each dash represents 2.5 seconds of travel. The camera was more or less centered on Polaris, above the chimney, so as the Earth rotated stars around Polaris moved and the curved lines show the apparent circumpolar path they follow.
   Thursday morning as I was walking my dog prior to leaving for work I spotted the ISS and whipped out my cellphone and captured some of its flight as a short video. The shaky motion comes from holding onto a 65 lb. dog on a leash with one hand and the cellphone in my other hand.
Click here to see the calculated path as done by the Heavens-Above web site.

   This morning I set up for a time lapse series as I did on Wednesday. With large trees as my southern horizon this flyover past the constellation of Orion and the bright star Sirius was sort of a challenge. This is a series of 10 pictures stacked to show as one picture.
Click here to see the calculated path as done by the Heavens-Above web site.

   Camera settings for all pictures: 18mm; f4.5; ISO 1600; 2.5 sec.

   A shout-out to Mrs. Soukup’s online Astronomy students.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Moon At Our Feet!

   On a regular basis the Moon, at some point in its cycle of phases, passes above Orion’s head on its way to a traverse of the Gemini constellation. Often the Moon’s orbit takes it past the feet of the Gemini twins and sometimes near the open star cluster, M-35. This is a group of several hundred stars with an apparent magnitude between 5 and 6 that is fairly easily seen as a fuzzy patch of light – like an out-of-focus star.
   However with the light from the nearby first quarter Moon brightening this part of the sky seeing M-35 will be very difficult.

   
   
   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

2016 September Equinox

   On Thursday September 22nd at 14:21 UT, (9:21 am CDT) the Sun will have reached the astronomical coordinates of 0 degrees declination and 12 hours of right ascension, or RA. This places the Sun within the boundaries of the constellation Virgo the Maiden, or as some would say, “the Sun is in Virgo.” This is the actual position of the Astronomical Sun as opposed to the pseudoscience of astrology which has the astrological Sun entering the constellation of Libra the Scales.
   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   Declination is the astronomical equivalent to latitude measuring from 0 degrees at the equator to 90 degrees at either pole. Right ascension, or RA, is like longitude except that there is only east RA. The globe is divided into 24 sections, and like meridians of longitude, these hour circles are 15 degrees wide at the celestial equator and taper to a ‘point’ at the north and south pole respectively. In RA the ‘hour’ circles are counted from 0 hours to 23 hours. The 0 hour circle is at the intersection of the ecliptic and the celestial equator in the constellation of Pisces the Fishes.
   In a class lesson about seasons today would be one of the two days during the year when the Sun would be described as being over the Earth’s equator. If you were at the Earth’s equator the Sun would have an altitude of 90 degrees, or straight up in your sky at your local time for midday. At that moment there would not be a shadow. However at any other latitude, north or south at midday, the Sun would be at an angle less than 90 degrees and there would be a midday shadow. (Midday is the local time when the Sun is halfway between local rising time and local setting time. At any midday the Sun is at its maximum altitude above the southern horizon in the northern hemisphere, or is at its maximum altitude above the northern horizon in the southern hemisphere.)
   What is often noted about an equinox day is the reminder that equinox means equal night as a reference to there being equal amounts of daylight, and night. Also on an equinox day the Sun would rise due east and set due west for virtually everywhere on the globe. The times for sunrise and sunset would be approximately 12 hours apart, and the rising time would be around 6 am local time, and the setting time would be around 6 pm local time.

Hola Moon doh

Hola ‘Moo’ndo! Think Globally.

   So why “September Equinox” instead of using the more familiar “Fall Equinox”. Primarily because the southern hemisphere is also changing seasons on this day however for the southern hemisphere this is the start of their spring season. Despite the opposite seasons it is somewhat of a northern hemisphere bias that traditionally we would call this day the “Autumnal or Fall Equinox”, and in March we would say the “Spring” or “Vernal Equinox”. I favor the use of the name of the month so that regardless of which hemisphere it is just simply the March equinox or the September equinox, and by extension we would also have the June solstice and the December solstice..
   
   This short video shows students at Colegio Menor San Francisco de Quito, a school in Quito Ecuador, measuring the altitude of the sun hourly on the day of the 2004 September Equinox. They were taking part in Project SunShIP, Sun Shadow Investigation Project. There are also some pictures showing a local midday shadow from other participating schools in the United States and U.K.

   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Moon Passes the Hyades

   Over the next couple of nights or early mornings the waning gibbous Moon will pass across the stars of the Hyades, a v-shaped open star cluster that makes up the face of Taurus the Bull. Depending on your geographical location you may see the Moon either pass very closely to the reddish star Aldebaran.
    From parts of Eastern Africa, Middle East, and South Asia the waning Gibbous Moon will be within 0.2o from Aldebaran.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

Venus Meets A Star

   Low over the western horizon after sunset on Sunday September 18th is the inner planet Venus within 2-3o from the blue-white star Spica in the constellation Virgo the Harvest Maiden. This would make for a striking duo when viewed with binoculars. Off to the west is Mars, Saturn, and the reddish star Antares in Scorpius the Scorpion.
   For those familiar with the mnemonic “Follow the arc to Arcturus, then speed to Spica”, look up toward the northwest for the reddish star Arcturus in Bootes the Herdsman to at least see the last part of the mnemonic.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

September Perigee Moon

18sep-perigee_moon   The Moon reaches perigee, (minimum distance from Earth), this month on Sunday September 18th. At that time the Moon will more or less be at a distance of 28.77 Earth diameters (361,896 km or 224,872 miles) from the Earth.
Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

The just past full waning gibbous Moon rises before midnight on the 17th and is easily seen brightening the western horizon before sunrise on the 18th. The Moon is near one of the outermost planets, and a couple of the Dwarf Planets. All of which are rendered ‘invisible’ as a result of the reflected light from the Moon.

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”


Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

My Bad!

“It’s Not You, It’s me.
I just have a few issues with causal language in the absence of longitudinal data.
My bad.”

eclipse-map-an   Yesterday morning I posted a blog about the penumbral lunar eclipse today, September 16th. I wrote that it would be visible across the United States. Actually, as I write this the eclipse has already taken place – but across Asia and western Europe!

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.