February’s Perigee Moon

feb-perigee-mon    Our Moon orbits around the Sun with the Earth and 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.
   This month the 27.5 day old waning crescent Moon reaches perigee this month, Thursday 27 February at 19:44 UT (1:44 pm CST). At that time the Moon will more or less be at a distance of 28.25 Earth diameters (359,985 km or 223,684 miles) from the Earth.

   
   
   
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 – Venus Occultation

1 Hour With the Moon

1 Hour With the Moon

   Observers in Western Africa, parts of India, and Southeast Asia, will see the 25 day old waning crescent Moon occult the planet Venus as the two rise in the east. The occultation begins at approximately 4:30 UT on Wednesday 26 February when Venus disappears behind the Moon, and ending with the reappearance of Venus about an hour later. An occultation of a planet by the Moon happens when the Moon passes between our line of sight of a planet and that planet – sort of like a lunar eclipse. However unlike a lunar eclipse the occultation is only visible from a narrow area across the Earth much like the shadow path for a total solar eclipse. If you are not in the occultation path then you will only see the Moon in conjunction (close) to the planet. This animated graphic is set to 1-minute intervals and shows the occultation from 4:30 UT to 5:30 UT.
Venus and the Moon

Venus and the Moon. 6am CST 25-26 February

   At the time of the occultation in my timezone of USA Central Time (CST) the Moon and Venus occultation is at 11 pm CST which means that for my location as well as much of the rest of the world will only see a Moon Venus conjunction. This animated graphic shows the morning skies at 6 am CST on both the the 25th and 26th of February. During that two day time period the Moon is conjunction with Venus both mornings.
   
   
   
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.

12 Hours With the Moon

12 hours with the Moon.

12 hours with the Moon.

   Yesterday I posted a description of the waning gibbous Moon passing by Mars and Spica. Tomorrow morning, Friday the 21st, The 21 day old waning gibbous Moon will come within 0.32o from the planet Saturn. This close conjunction occurs at 22 UT and depending on your longitude/time zone you may only see the Moon close to Saturn, as I will, but not the closest at 0.32o. Each frame of this animated graphic shows the Moon and Saturn from 5 am CST to 5 pm CST at 1-hour intervals. I have switched off daylight and the horizon so the motion of the Moon as it orbits to the east and rising into the morning skies toward the west may be observed without their interference.
Click on graphic to see it full size.

Click on graphic to see it full size.

   At my location in the U.S. central time zone 22 UT is 5 pm CST, and the waning gibbous Moon will have already set by then. And the waning gibbous Moon at this late phase rises before sunrise and is always visible in the morning and daytime skies. So my view of the Moon and Saturn will be before sunrise when the two are approaching the minimum separation. Close but no cigar as the saying goes.

   
   
   
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.

Saturn, Mars, and Spica

Click on graphic to see it full size.

Click on graphic to see it full size.

   Look toward the south-southwest skies before sunrise tomorrow, Wednesday morning the 19th of February to see the 19 day old waning gibbous Moon. Within a few degrees from the Moon is the bluish-white star Spica in the constellation Virgo the Harvest Maiden, and the ‘Red Planet’ Mars. All three will fit within the field of view of an average pair of binoculars.

   
   
   
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.

Sun Not in Pisces Today

The view from Earth - 18 February.

The view from Earth – 18 February.

  According to the pseudoscience of astrology the Sun enters the constellation of Pisces the Fishes today, 18 February at 12 pm CST (18 UT). When in fact the actual position of the Sun today is within the boundary of the constellation of Aquarius the Water Bearer, as this graphic shows. Actually the Sun had just entered Aquarius 2 days ago.

   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.
   
   
   
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.

Sun Enters Aquarius Today

16 February

16 February

   Today Sunday 16 February at 8 am CST, (14 UT), the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Capricornus the Sea Goat and into the constellation of Aquarius the Water Bearer. This is the true or actual position of the Sun as opposed to the pseudoscience of astrology which usually has the astrological Sun one constellation ahead or east from the Astronomical Sun’s position. Which will be Tuesday 18 February when the sun is not in Pisces according to astrology.

   
   
   
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.

Mercury at Inferior Conjunction

orbits   From our perspective on Earth, the inner planet Mercury appears to move back and forth from the left side of the Sun to the right side and then back to the left side – over and over. This is our view of the planet as Mercury revolves around the Sun. From an overhead view we would see Mercury’s orbit circular as shown in the graphic to the right. However since the Earth’s orbit is essentially on the same plane, or level, as Mercury’s orbit we see Mercury move from one side of the Sun to the other side. Sort of back and forth motion from the east to the west side of the Sun with Mercury, today, centered between the two extremes (elongations) and at inferior conjunction.

From this Inferior Conjunction to the next one.

From this Inferior Conjunction to the next one.

   Mercury’s orbit is divided into four parts based on the planets position (location) relative to the Earth and the Sun somewhat like we describe phases of our Moon. Starting with today Mercury is between the Earth and the Sun at inferior conjunction. In approximately 1/4th of a revolution Mercury will be to the right of the Sun at western elongation – when Mercury rises before sunrise, and is known as a ‘morning star’. One-fourth of a revolution later Mercury is on the opposite side of the Sun, not visible from the Earth, and is at superior conjunction. Continuing along its orbital path Mercury will reach eastern elongation, on the left side of the Sun when it will rise after the Sun rises and sets after the Sun, as an ‘evening star’.
mercury-phases-ani   Viewing Mercury through a telescope will reveal phase changes similar to our Moon with the biggest difference being that there is no full Mercury phase—at least not one that we can see from Earth. Today while at inferior conjunction the Sun side of Mercury is reflecting sunlight and so like our new Moon phase we do not see either. Mercury moves from inferior conjunction toward western elongation and as it does so it starts as a relatively large crescent phase and by western elongation Mercury’s apparent size has decreased but it has waxed toward a quarter phase and 50% illuminated. As Mercury moves toward superior conjunction its apparent size decreases while its phase waxes through the gibbous shape. Once the planet moves away from the Sun and superior conjunction Mercury will be again seen in the gibbous phase but appears relatively small. As it continues along its orbit toward eastern elongation Mercury wanes to a larger appearing quarter phase and 50% illuminated. From eastern elongation to inferior conjunction Mercury’s apparent size increases while it wanes toward a thin crescent shape.
On March 14th Mercury reaches western elongation.

   
   
   
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.

It’s Summer – On Mars

A Martian Year

A Martian Year – at One Earth Month Intervals

   Sunday January 3rd is the summer solstice on the planet Mars as the planet transitions from spring to summer during its 684 Earth day orbit around the Sun. Seasons on Mars are marked by the planet’s heliocentric longitude coordinates using the position of Mars along its orbit around the Sun. Each seasonal start/ending point is 90 degrees apart, but because of its elliptical-shaped orbit each Martian season is of varying lengths. At the Martian summer solstice Mars is at 90 degrees longitude.
Click on graphic to see it full size.

Click on graphic to see it full size.

   I’m not exactly sure why this particular date is used but by international agreement astronomers have selected 11 April, 1955 as 0 degrees for year 1 of this Martian calendar. What this means is that on Sunday January 3rd, Earth time, it is the start of summer for year 33 using the aforementioned calendar system.

Year 33
0 degrees — Spring Equinox — June 18 2015
90 degrees — Summer solstice — January 03 2016
180 degrees — Fall Equinox — July 04 2016
270 degrees — Winter Solstice — November 28 2016
Year 34
0 degrees — Spring Equinox — May 05 2017
90 degrees — Summer solstice — November 20 2017
180 degrees — Fall Equinox — May 20 2018
270 degrees — Winter Solstice — October 16 2018

Learn a little (or a lot) more about Mars at the NASA/JPL Mars Curiosity mission web site.

Here is approximately 3 minutes worth of Mars from the Orbit performance.

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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.

Happy Valentine’s Day

heart_shaped_cloud   Happy Valentine’s Day to all my readers and followers.
   Despite the cloudy skies in the picture have clear skies over whatever road you you travel.

   
   
   
   
   
   
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.

Saturn at West Quadrature

Click on graphic to see it full size.

Click on graphic to see it full size.

   Today, 11 February, the position of the planet Saturn with respect to the Earth and the Sun places this ringed planet at what is called western quadrature. Saturn is at a 90 degree angle from us as this graphic shows. Think third quarter Moon as that is a fair comparison of the relative positions. At this position Saturn leads the Sun across the sky from east to west as the Earth is rotating, meaning that Saturn rises before the Sun and also sets before the Sun.
   Where is Saturn now? Click here to see a graphic showing Saturn, two additional planets, and some of the brighter stars over the eastern horizon at 6:30 am CST.

Learn a little (or a lot) more about Saturn by visiting the Cassini at Saturn mission web site.
Click here to go to the Cassini Mission web site.
Click here to go to the Cassini Mission Flyby web page to see when the next Saturn satellite flyby will be.

   This is a short 5 minute video I made as part of a live musical performance called “Orbit” that I was part of in May 2011. This is a piece from the much longer tour of the solar system performance and video and shows Saturn and some of its moons as viewed from the Cassini spacecraft that month.

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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.