Category Archives: Astronomy

Mars and the 7 Sisters

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   The planet Mars has been steadily orbiting eastward and is currently moving past the open star cluster the Pleiades. On Wednesday evening March 3rd Mars will be at its closest to the Pleiades coming within about 3-4o from the open star cluster as it passes by.

   Use binoculars or a low-power telescope eyepiece to view Mars and the Pleiades.
   
   
   
   
   
   
   
   
   
   
   
   

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.

March Moon at Perigee

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Whoops!! I did tis way too early!!! The Moon is actually at perigee Not apogee.
   Our Moon reaches perigee, (closest to Earth), for this orbit, on Monday March 1st. For this perigee the 18.25-day old waning gibbous Moon will be at a distance of 28.64 Earth diameters, 227,049 miles (365,400 km) from the Earth.

   On the date of the perigee Moon the waning gibbous Moon will rise around mid-evening local time. Interestingly, as it rises, the Moon will be part of the mnemonic: “Follow the arc to Arcturus and then speed to Spica.”


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

   
   
   
   

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.


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Inner Meets Outers – In A Triple Conjunction

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   Sunday morning February 28th the innermost planet, Mercury, and two of the ringed outer planets, Jupiter and Saturn, will be in a triple conjunction as Mercury moves eastward past Saturn and then Jupiter. Mercury will be about 3-4o from Saturn and about 2-3o from Jupiter.
   All three will almost fit within the field of view of binoculars and should make for an interesting contrast in apparent magnitudes however Jupiter (-1.97) far outshines Mercury (0.30) and Saturn (0.71).

   
   
   

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 on the Move – Always

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   Over the next few evenings the waxing gibbous Moon will move eastward passing by the open star cluster known as the Beehive Cluster this evening and then in a couple of days, as a full Moon, will be close to the heart of Leo the Lion the star Regulus.
   While the Moon may be close to the open star cluster the waxing gibbous Moon with its considerably greater apparent magnitude will outshine the star cluster making it not visible. Wait a few days and then aim your binoculars or low power eyepiece for a better view.

   
   
   

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 Meets the Twins

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   Tuesday evening February 23rd the 12-day old waxing gibbous Moon will be about 2o from Pollux, one of the two ‘Twin’ stars of the constellation Gemini the Twins. The other brother is Castor, which is about 6o away from the Moon.

   
   
   

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.

February Moon at Northernmost Declination

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click on graphic to see it larger   Our Moon does not follow a path with the Earth around the Sun that is parallel with the Earth’s orbit, the ecliptic. The Moon is tilted or inclined by approximately 5.14o from the Earth’s orbital path meaning that there are places where the Moon’s orbital path intersects or crosses the Earth’s orbital path, the ecliptic. At up to 3 times each month the Moon will cross the ecliptic moving south or north in what is called a node crossing – one ascending and the other descending.

    However with regard to the celestial equator, an extension of the Earth’s equator into space, the maximum northern most declination for our Moon, as measured from the celestial equator, could be as much as about 28.64o either north or south based on the Earth’s axial tilt of 23.5o plus the Moon’s inclination angle 5.14o (23.5 + 5.14 = 28.64o).

    This month our Moon reaches a maximum northernmost declination of 25.1o on Monday February 22nd.

   
   
   

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.

February Moon at Ascending Node

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   Saturday February 20th the 9-day old waxing gibbous Moon will be crossing the plane of the ecliptic moving north. This is known as the ascending node, one of two intersections the Moon’s orbital path has with the ecliptic. The ecliptic is actually the Earth’s orbit, and the Moon’s orbit is inclined about 6o from the ecliptic. So there are two node intersections, the ascending and descending nodes.

   On the day of the node crossing the 9-day old waxing gibbous Moon will be over the southwestern horizon later during the evening after sunset local time. Watch for the Moon to be about 8o from the reddish star Aldebaran in the open star cluster the Hyades in Taurus the Bull.

   Does our Moon actually go around the Earth as many graphics show? 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*
*Click here to read my Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)
   
   
   
   
   
   
   

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.

Mercury – Saturn – Jupiter Together Again!

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   Saturday morning February 20th in the hour or so before the Sun rises look for the innermost planet Mercury to be about 4-5o from Saturn and Jupiter. All three should fit within the field of view of binoculars, but the three planets will be low above the horizon.

   
   
   

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.

Sun Not In Pisces-2021

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  According to the pseudoscience of astrology the Sun enters the constellation of Pisces the Fishes on Thursday February 18th. In fact the actual position of the Sun is still within the boundary of the constellation of Aquarius the Water Bearer, as this graphic shows. 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.

   
   
   

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.

February Moon at Apogee

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   Our Moon reaches apogee, (furthest from Earth), for this orbit, on Thursday February 18th. For this apogee the 7.25-day old waxing crescent Moon will be at a distance of 31.70 Earth diameters, 251,282 miles (404,400 km) from the Earth.

   On the date of the apogee Moon the nearly first quarter Moon will be high above the southern horizon and will be within a few degrees from the planet Mars.


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

   
   
   
   

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.


Also Follow me and other great resources at Feedspot.