Moon Near Saturn


   Sunday morning, April 16th the 19-day old waning gibbous Moon will rise near the planet Saturn. The two will be within the 7o field of view of 10×50 binoculars and will be easily seen over the eastern to southeastern horizon in the hours before the sun rises.
   
   
   

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.

Full Moon Near Jupiter and Spica


   Monday evening April 10th the full Moon will be about 3o from Jupiter and about 5o from the blue-white star Spica in Virgo the Harvest Maiden as the trio rises in the east.

   
   
   
   
   
   

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.

Jupiter at Opposition: 2017

Zooming in on Jupiter at Opposition   Friday April 7th, the outer giant planet Jupiter reaches the point in its orbit around the Sun that places the Earth in between Jupiter and the Sun. This is known as opposition, and opposition is an orbital position that applies to solar system objects (outer planets, dwarf planets, asteroids, comets, etc.) orbiting the Sun beyond the Earth’s orbit. An object at opposition will have approximately the same heliocentric longitude as the Earth’s heliocentric longitude. So on Tuesday both planets will have a heliocentric longitude of about 167o.
   An opposition of Jupiter occurs approximately every 13 months because both Earth and Jupiter are moving. After one Earth Revolution, an Earth year, the planet Earth will be where it was the previous year at opposition with Jupiter. However Jupiter will not be there because it has moved during the past year as well. It will take the Earth about an extra month or so to catch up with Jupiter. Earth moves 360o each year while Jupiter moves approximately 12o each Earth year.

Sunset Local Time

Sunset Local Time

   When an object is at opposition it rises at approximately the same time as local sunset and that same object at opposition sets at approximately the time of local sunrise. In other words an object at opposition will be up all night from sunrise to sunset.
   Picture our Moon at full phase and how it is directly opposite the Sun, with the Earth in between. The full Moon in effect is at opposition but we call it the full Moon instead. And like Jupiter at opposition, a full Moon rises at sunset, sets at sunrise and is visible all night.


   Jupiter rising with Spica.
   
   
   
   
   
   
   
   
   
   
   
Take a brief tour of the Jovian (Jupiter) system. Music by Dark Matter.
Live recording of music written by Richard Johnson. Video by me!

   
   
   

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.

Duck! Said Scorpius to Sagittarius

   Over the next several mornings, before the Sun rises, the Moon, as it wanes from gibbous to last quarter phase, glides past the stars of Scorpius the Scorpion and Sagittarius the Archer and the ringed planet Saturn.
   Apparently Archery is so loud that Sagittarius didn’t hear the warning and gets a face full of the Moon on the 21st.
   In the background is the Milky Way, but for the most part it will be difficult to see due to the bright reflected light from the Moon.
   Off to the west is Jupiter and Spica. Jupiter has been in retrograde motion since last month and is gradually moving west away from Spica.
   
   
   
   
   
   
   In the background is the Milky Way, but for the most part it will be difficult to see due to the bright reflected light from the Moon.

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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 Apogee

 Our Moon reaches apogee, (greatest distance from Earth), on Saturday March 18th. At that time the Moon will more or less be at a distance of 31.72 Earth diameters (404,640 km or 251,432 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*

*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?”

   On the morning of the apogee Moon the 20-day old waning gibbous Moon rises a couple of hours before the Sun and is visible over the southern horizon.

   
   
   

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.

Moon Near Jupiter and Spica


   Tuesday evening March 14th look for the waning gibbous Moon to be about 5-6o from the giant planet Jupiter and the blue-white star Spica. Both of which are within the constellation of Virgo the Harvest Maiden. The trio will make for an interesting view with binoculars.

   
   
   

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.

The Moon, Jupiter, and Spica – Together Again


   Wednesday February 15th the 18-day old waning gibbous Moon will be within a few degrees from the planet Jupiter and the blue-white star Spica in Virgo the Harvest Maiden as they rise in the east a few hours before sunrise local time.
   All three will fit within the field of view of a pair of 7×50 binoculars as this graphic shows.

   
   
   
   
   
   
   
   
   
   
   
   

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.