Astronomical Information

Stargazing Notes

Stargazing Notes

    April 2018 Sky Events

    As the Winter sparkliers wheel off to the west, we find the harbinger of Spring, Leo the Lion, high in the Southern sky.

    Sunday, April 1st
    Today is Easter Sunday and a total Eclipse of the Sun! ….and April Fool’s Day, one of the first two is not true.  Mercury reaches inferior conjunction, passing between the Sun and Earth, at 2 p.m. EDT. The innermost planet will return to view before dawn in late April.

    Monday, April 2nd
    Plan to get up about an hour before dawn (around 6:30 am) to view Saturn and Mars in conjunction, only 1.3 degrees apart.  The two planets will be just above and slightly to the left of the teapot of Sagittarius in the SSW.  Saturn will ride above and to the left of the Red Planet.

    Saturday, April 7th
    The early riser (6:15 am) will be treated to the sight of a nearly Last Quarter Moon about 1 degree from Saturn, still close to, but now on the right side of Mars.  The two planets will be on the left side of the Moon.  The three will be above Sagittarius in the SSW part of the sky.

    Sunday, April 8th
    The Moon is at its Last Quarter phase.  It is now three quarters of the way around the Earth.  Saturn and Mars are now to the right of the Moon.

    Monday, April 15th     
     The New Moon will be located on the same side of Earth as the Sun, with the far side illuminated, it will not be visible to us in the night sky.

    Wednesday, April 17th
    The merest hint of a Crescent Moon will be just to the left of Venus in the western sky 45 minutes after sunset.

    Thursday, April 18th 
    A young Crescent Moon can be viewed in the face of Taurus the Bull, in the western sky, above and to the left of Venus, 45 minutes after sunset .  Sunset is around 8:30.       

    Friday, April 20th
    Statewide Astronomy Night 5-8 pm FREE at the Museum.  We will have various astronomy related activities for all ages.  "IBEX: Search for the Edge of the Solar System,” will premiere, followed by a live star talk focusing on the Spring sky and its constellations in southwest Michigan. The evening will end in the theater with Dr. Nicole Zellner's presentation, "ANSMET: Space Exploration Way Down UnderF                 

    Sunday, April 22nd
    The Moon is in its First Quarter.  To celebrate lets have Earth Day!   

    April 22, 23
    Peak time for the Lyrids Meteor Shower. This is an average shower, producing around 20 meteors per hour at its peak. It is produced by as the Earth passes through dust particles left behind by comet C/1861 G1 Thatcher, discovered in 1861. It runs annually from April 16-25 and peaks this year on the night of the 22nd and morning of the 23rd . These meteors can sometimes produce bright dust trails that last for several seconds. The Moon will set shortly after midnight, leaving dark skies for what can be a good show. Best viewing will be from a dark location after midnight.   Meteors often appear to radiate from the constellation Lyra, but can appear anywhere in the sky.  At Midnight Lyra will be in the SW portion of the sky.

    Sunday, April 29th 
     
    The Full Moon, located in Libra, will be on the opposite side of Earth as the Sun, thus fully illuminating its face.  As the Sun sets we will see Moonrise at about 8:20 pm.   This full moon was known by early Native American tribes as the Full Pink Moon because it marked the appearance of the moss pink, or wild ground phlox, which is one of the first spring flowers. This moon has also been known as the Sprouting Grass Moon, the Growing Moon, and the Egg Moon. Many coastal tribes called it the Full Fish Moon because this was the time that the shad swam upstream to spawn
    Mercury is at its greatest Western Elongation of 27 degrees from the Sun.  This is the best time to view Mercury since it will reach its highest point above the horizon in the morning sky.  Look for the planet low in the eastern sly just before sunrise.

     

    Astronomical Definitions

    • Perihelion - the instant when a planet is closest to the Sun
    • Aphelion - the instant when a planet is furthest from the Sun
    • Perigee - the instant when the Moon is closest to Earth
    • Apogee - the instant when the Moon is furthest from Earth
    • Inferior Conjunction - the instant when a planet passes between Earth and the Sun (Mercury or Venus)
    • Superior Conjunction - the instant when a planet passes on the opposite side of the Sun from Earth (Mercury or Venus)
    • Greatest Elongation - elongation is the apparent angle between a planet and the Sun as seen from Earth; during eastern elongation (E), the planet appears as an evening star; during western elongation (W), the planet appears as a morning star
    • Opposition - the instant when a planet appears opposite the Sun as seen from Earth
    • Conjunction - the instant when a planet appears closest to the Sun as seen from Earth
    • Occultation - the Moon occults or eclipses a star or planet
    • Ascending Node - the point where a planet crosses from the southern to northern portion of its orbit
    • Descending Node - the point where a planet crosses from the northern to the southern portion of its orbit