Astronomy Info & Events - May

Moon Phases

May 2: First Quarter Moon

MAy 10: Full Moon (the Flower Moon)

May 18: Last Quarter Moon

May 25: New Moon

Special Events

The International Space Station (ISS) will have visible passes during the night throughout all of May.  Check out the website to find out the exact times when the ISS will be visible from your location.  The ISS will be seen as a bright moving point of light, moving in an arc from the west to the east during its visible passes.

May 3: Mars will be 6 degrees above the bright reddish star Aldebaran. Difficult to see due to the Sun’s setting glow.

May 4: Lunar straight wall visible tonight through a telescope. Star Wars Day "May the Fourth Be With You" 

May 5: Eta Aquariid meteor shower peaks and International Space Day

May 8: Royal Astronomical Society of Canada (Edmonton Centre) meeting Times:  7:30 p.m. – 9:30 p.m. in the Margaret Zeidler Star TheatreFree for anyone to attend.  See for more details.

May 12: ISS astronauts Peggy Whitson and Thomas Pesquet will take a spacewalk starting at about 6 a.m. MDT (1200 GMT) and lasting about 6.5 hours.

May 17: Mercury at greatest western elongation of 26 degrees.

May 22: Waning crescent Moon below Venus in the morning eastern sky.

May 24: Northern summer begins on Saturn.

May 25: Closest lunar perigee of the year, 357209 km.  Large tides for coastal areas.

Visible Planets

Mercury is visible with some difficulty low along the eastern horizon just before sunrise during the month.  It reaches its point of greatest western elongation on May 17 (furthest angular separation from the Sun of 26 degrees).  Mercury then disappears into the glare of the rising Sun by the end of the month.  

Venus is visible low along the south-eastern horizon before sunrise during the month.  Look for the waning crescent Moon near Venus in the predawn hours of May 22.  Venus is unmistakable as the brightest object in the predawn eastern sky.

Mars is found very low along the western horizon at sunset and is located in the constellation of Taurus, the bull.  From our latitude, Mars may be too difficult to see as it will be in the Sun’s setting glow all month long.

Jupiter is found in the constellation of Virgo, the maiden, just above the bright star, Spica.  It is located in the southwest sky at sunset and then follows a shallow arc through the night in the southern sky until it sets in the west before sunrise.  Jupiter will be a highlight of telescopic observing this month at the TELUS World of Science - Edmonton’s RASC Observatory.  Check our website for hours of operation.

Saturn rises after midnight local time along the southeast horizon and then is found low in the south by sunrise. Located just above the spout of the “teapot” of the constellation of Sagittarius, the archer, Saturn continues its retrograde motion this month as it slowly approaches opposition on June 15.  Look for Saturn very close to waning gibbous Moon on May 13 and 14.