Along the Ecliptic

   Every once in a while the planets arrange themselves along the horizon and when that happens visualizing the ecliptic is somewhat obvious. For the next week or so all of the naked-eye visible planets except Mars, plus Neptune and Dwarf Planet Ceres, will be above the horizon at sunset local time. If you wait about an hour the Moon and the planet Uranus will rise above the eastern horizon as Mercury and Venus have set in the west.
   The ecliptic is actually the Earth’s orbit and it is used as a reference ‘line’, properly known as the plane of the ecliptic, for all of the Sun orbiting objects. Since few if any Sun orbiting objects have orbits that are on the same plane as the Earth but rather these objects are tilted or inclined either above or below the plane of the ecliptic. This is know as inclination. (Table Source: https://en.wikipedia.org/wiki/Orbital_inclination)

   
   
   

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.


Also Follow me and other great resources at Feedspot.

Venus at Superior Conjunction


   On Wednesday August 14th the inner planet Venus will have moved into superior conjunction – on the opposite side of the Sun from the Earth. Venus will reappear on the east side of the Sun later next month and start becoming visible in the evening skies over the western 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.


Also Follow me and other great resources at Feedspot.

Waning Crescent Moon – Venus Conjunction

   Saturday morning June 1st watch for a very thin 27.5-day old waning crescent Moon to rise with the inner plane Venus. The Moon will be about 5o from Venus, and despite the Moon’s thin appearance its apparent magnitude of -9.0 will still outshine Venus apparent magnitude of -3.80. Nonetheless both should make a striking pair over the horizon before sunrise local time.

   
   
   

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.


Also Follow me and other great resources at Feedspot.

Moon – Uranus Conjunction

   Friday May 31st the 26.5-day old waning crescent Moon will be within about 4o from the outer ringed planet Uranus. Both rise around 1 hour before sunrise local time. The waning crescent Moon and Uranus will easily fit within the field of view of binoculars.
   However with two distinctly different apparent magnitudes (Moon -10.0 and Uranus 6.80) seeing Uranus will be a challenge compared to the much brighter Moon. Even more dimmer is the dwarf planet Ceres (apparent magnitude 18.67) located about 11o west from the crescent 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.


Also Follow me and other great resources at Feedspot.

Waning Crescent Moon – Venus Conjunction

   Wednesday and Thursday mornings, May 1st and 2nd the 26 to 27-day old thin waning crescent Moon will pass by the inner planet Venus coming the closest on the 27th when the two will be separated by about 3-4o. A day later, Friday, the very thin waning crescent Moon will be near Mercury and the outer planet Uranus, but the Sun will be less than 45 minutes behind them – meaning the sky may be too bright to see the Moon or Mercury.
   Further to the west the outer planets Saturn and Jupiter are visible in the area around Sagittarius and Scorpius. Even a bit further west is the closest Dwarf Planet to the Earth, former asteroid Ceres.


   
   
   

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.


Also Follow me and other great resources at Feedspot.

April Moon at 2nd Apogee

   Our Moon reaches apogee, (greatest distance from Earth), on Sunday April 28th. At that time the Moon will more or less be at a distance of 31.85 Earth diameters 251,392 miles (404,577 km) from the Earth.

Does our Moon actually go around the Earth? 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*

   On the day of the apogee the 24-day old waning crescent Moon will be over the southeastern horizon 1-2 hours before sunrise local time.

*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 return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

A Tale of Two Phases

   Over the next couple of weeks the two inner planets, Mercury and Venus, will be above the eastern horizon in the hour or two before the Sun rises. Given its much brighter apparent magnitude (-3.92) Venus will be more noticeable. However Mercury (0.03) is only a few degrees away, down to the left as they both rise. This graphic shows the two planets (sizes greatly enlarged for the graphic) and their respective orbital paths. Both planets are moving eastward toward the Sun and will eventually catch up with and move to the opposite side of the Sun, behind the Sun as we view from Earth to their respective superior conjunction.

   As these two planet orbit toward the Sun they pass through phase changes much like our Moon. Currently both planets are waxing gibbous but as they move into superior conjunction they will be at full phase. But unlike our Moon at full phase the inner planets are not visible at their respective full phase. When they do reappear on the east side of the Sun they will be again at gibbous phase, and will be following the Sun across the sky, setting after the Sun as an ‘evening planet’.

   
   

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.


Also Follow me and other great resources at Feedspot.