Give Me a Break!

saturn-huge   This was recently posted on Facebook, which we all know to be the ultimate source for correct information. Let me emphatically state that no this is not going to happen. Saturn will not somehow move near enough to the Earth to be that large, nor from its actual orbital position ever appear that large; even with opposition about 1 month away, in early June. On May 1st Saturn will be at a distance of 9.16 AU (1,370,316,495 km; 851,475,194 miles) from the Earth, and the apparent size of Saturn, as seen from that distance is about 18″ (18 arcseconds). For comparison the full Moon has an apparent diameter of about 30′ (30 minutes) or 0.5o.

    I’m not sure which is worse, the person that posted this, or the people that blindly share the post without first verifying that it is true.


   On May 1st Saturn rises before sunrise local time and is a few degrees east from Mars, and a few degrees north and west from the reddish star Antares in Scorpius the scorpion.

   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Mercury Begins to Retrograde


   Friday April 29th the innermost planet Mercury starts its retrograde motion as it moves away from its recent eastern elongation toward inferior conjunction, a node crossing, and a transit of the Sun on May 9th.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

A Tale of Two Junos

Juno #1:
   Tuesday April 26th asteroid 3 Juno will be at opposition, that is, it will be 180o from the Sun with the Earth between the two. At opposition, any Sun orbiting object beyond Earth rises at about local time for sunset and sets at local time for sunrise. At about 9th-10th magnitude the asteroid will be too faint to be seen with binoculars or the naked eye. There is, however, a much brighter asteroid shining at a about 5th magnitude, and a few degrees south from Jupiter. This is asteroid Hygiea, the 4th largest asteroid.
   Asteroid 3 Juno was the third asteroid discovered, hence its numerical prefaced name. It was discovered by German astronomer Karl L. Harding in 1804, and it is the 11th largest asteroid.
   Follow asteroid 3 Juno using the Heavens Above web site.

juno-jupiterJuno #2:
   NASA’s Juno mission to Jupiter is very near the end of its 5 year journey across the solar system. Launched in August of 2011 the solar powered spacecraft is expected to arrive at Jupiter on July 4th of this year. The Juno mission will place the spacecraft into a polar orbit that will consist of 30 orbits around the planet with each orbit lasting 11 days while Jupiter rotates below every 10 hours. After arrival the mission has a planned length of one year ending in October 2017 with the spacecraft de-orbiting and falling into the planet’s atmosphere.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Moon Sort of in Conunction with Mars and Saturn

click on graphic to see it full size
   Monday morning April 25th the 18 day old waning gibbous Moon will be within a few degrees from the planet Mars and a few more degrees from the planet Saturn. Not really a true conjunction but the trio will all fit within a 7×50 binocular field of view.

25apr-bino   
   
   
   
   
   The reddish star Antares, the ‘heart’ of Scorpius the Scorpion is 4-5o south from Mars and is just outside the binocular field of view.

   
   
   
   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

April Apogee Moon

21apr-apogee_moon   Our Moon reaches apogee, (greatest distance from Earth), on Thursday April 21st. At that time the Moon will more or less be at a distance of 31.85 Earth diameters (406,351 km or 252,495 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?”

   The 14-day old full Moon rises aroung sunset local time and is visible all night, setting at aroun sunrise local time.

   
   
   

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.

Mars and Saturn – Close But Not For Long


   The planet Mars, having just begun its retrograde motion, will come within about 7o from Saturn this Wednesday April 20th. This is the closest the two planets will be for a while as the separation between the two increases while Mars retrogrades toward the west.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Sun Not In Taurus

April 19th  According to the pseudoscience of astrology the Sun enters the constellation of Taurus the Bull on Tuesday April 19th. When in fact the actual position of the Sun on the 19th is still within the boundary of the constellation of Aries the Ram, as this graphic shows. Actually the Sun had just entered Aries the day before on April 18th.

   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.

April Moon at ascending Node

feb24ascending-node    On Monday April 18th the 11.5-day old waxing gibbous Moon will be crossing the plane of the ecliptic moving north relative to the ecliptic. 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.

click on graphic to see it larger
   The 11.5-day old waxing gibbous Moon rises around 5 pm local time.

   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 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?”

   
   
   
   
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 Aries

April 19th   Monday April 18th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Pisces the Fishes and into the constellation of Aries the Ram. 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.
   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 more observing information for this month.

Mercury at Eastern Elongation

orbital-positions    On Monday April 18th Mercury, the innermost planet, will reach its orbital position known as greatest eastern elongation. At that moment Mercury, the Sun, and the Earth, would be arranged in something close to approximating a right angle as this graphic shows.
   From our perspective the orbits of Mercury and Venus appear to move from one side of the Sun to the other – out to the left (east) from the Sun to eastern elongation, then reverse and move westward (inferior conjunction) between the Earth and the Sun to western elongation. From there the inner planet moves eastward going behind the Sun (superior conjunction) and eventually reappearing on the eastern side of the Sun for an eastern elongation. Repeat over and over – do not stop!
   In less than a month, on May 9th, Mercury will move into inferior conjunction as it crosses the ecliptic moving south setting up a transit by Mercury across the Sun.


   Currently Mercury is very visible shining at nearly 0 magnitude over the western horizon at sunset.

   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.