RASC Hamilton

Moon Moves Through the Scorpion’s Claws (overnight)
2025-04-15 20:00 - 2025-04-16 05:00 (America/Toronto)
When the bright, waning gibbous moon clears the trees to the southeast in late evening on Tuesday, April 15, it will be shining close to the line of medium-bright stars that form the claws of Scorpius, the Scorpion. From upper left to lower right, their names are Graffias (or Beta Scorpii), Dschubba (or Delta Scorpii), Pi Scorpii, and Rho Scorpii. Skywatchers viewing later that night, or in more westerly time zones, can see the moon approach (green line) and then cross in front of Pi Scorpii around 5 a.m. EDT or 09:00 GMT. Lunar occultations are safe to watch with eyes, binoculars, and telescopes. Use an app like Starry Night or Sky Safari to look up the timings where you live.

Bright Moon Covers Antares (overnight)
2025-04-16 20:00 - 2025-04-17 05:00
On Wednesday evening, April 16, observers in a zone extending from the southern Atlantic Ocean, the southern part of Africa, the Kerguelen Islands, and eastern Antarctica can watch the motion (green line) of the bright, waning gibbous moon cross in front of (or occult) the very bright, reddish star Antares, which marks the heart of Scorpius. Lunar occultations are safe to watch with eyes, binoculars, and telescopes. Use an app like Starry Night or Sky Safari to look up the timings where you live.

The Whirlpool and Pinwheel Galaxies (all night)
2025-04-18 20:00 - 2025-04-19 05:00
On evenings during mid-April, the Big Dipper is positioned nearly overhead with its handle pointed down to the east. On this week’s moonless nights, two impressive galaxies can be seen in binoculars (orange circle) and backyard telescopes by using the bright star Alkaid at the tip of the dipper’s handle to find them. The Pinwheel Galaxy, or Messier 101, is a spectacular, large, face-on spiral galaxy positioned a slim palm’s width to the lower left (or 5.5 degrees north) of Alkaid, forming an equilateral triangle with Mizar, the double star at the bend of the dipper’s handle. This relatively close galaxy (21 million light-years away) is nearly as large as the full moon in the sky. Since the galaxy’s light is spread over such a large area, its overall brightness is lowered. Aim your binoculars several finger widths to the upper right (or 3.7 degrees to the southwest) of Alkaid to discover the iconic Whirlpool Galaxy, aka Messier 51. This spiral galaxy’s angular size is smaller, but it will look somewhat brighter in your binoculars and telescope. A secondary galaxy core designated NGC 5195 close beside M51 is linked by a bridge of material.

Ursa Major Galaxies (all night)
2025-04-19 20:00 - 2025-04-20 05:00
The Big Dipper asterism and its home constellation of Ursa Major are very high in the northern sky in late evening during mid-April – ideal for observing the spectacular galaxies they host in strong binoculars or backyard telescopes on the dark nights this weekend. Draw a line connecting the dipper stars Phecda to Dubhe, and extend it by an amount equal to their separation to arrive at the galaxy named Bode’s Nebula, otherwise known as Messier 81. It’s a magnitude 6.9 spiral galaxy oriented not quite face-on to Earth, making it appear relatively large and bright. A smaller, magnitude 8.4 galaxy named the Cigar or Messier 82 is located less than a finger’s width below (or half a degree to the celestial north of) it. That allows both galaxies to be viewed together in the eyepiece of a telescope at low magnification (inset). Several other fainter galaxies can be found within a few degrees of Bode’s Nebula.

Mercury at Greatest Western Elongation (before sunrise)
2025-04-21 00:00
On Monday, April 21, Mercury (orbit shown in red) will reach its greatest angle of 27.4 degrees from the morning sun and maximum visibility for its current morning apparition. With Mercury positioned low in the eastern sky and well below the tilted morning ecliptic (green line), this appearance of the innermost planet will be a poor one for Northern Hemisphere observers, but an excellent one for those viewing Mercury from the tropics and the Southern Hemisphere. The optimal viewing times at mid-northern latitudes will start around 5:45 a.m. local time. Viewed in a telescope (inset) the planet will exhibit a waxing, almost half-illuminated phase.

Third Quarter Moon (at 01:35 GMT)
2025-04-21 19:00 - 22:00
The moon will reach its third quarter phase on Monday, April 21 at 01:35 GMT, which converts to 9:35 p.m. EDT or 6:35 p.m. PDT on Sunday, April 20. Third quarter moons rise around midnight in your local time zone, and then linger in the southern sky after sunrise. At third, or last, quarter the moon is illuminated on its western side, towards the pre-dawn sun. The week of dark, moonless evening skies that follow this phase will be ideal for observing deep sky targets in binoculars and telescopes, especially spring galaxies.

Lyrids Meteor Shower Peak (overnight)
2025-04-22 20:00 - 2025-04-23 05:00
The annual Lyrids meteor shower, derived from particles dropped by comet C/1861 G1 (Thatcher), runs from April 16 to 29. It will peak in intensity at approximately 9 am EDT on Tuesday, April 22, but some meteors should be seen while the shower’s radiant point near the bright star Vega in Lyra climbs the eastern sky starting late on Monday night, April 21. The Lyrids can produce up to 15-20 meteors per hour at the peak, with occasional fireballs. The waning crescent moon rising in the wee hours shouldn’t hinder the shower this year. For best results, try to view the meteors from a safe location that has a wide open sky free of light pollution. Don’t focus your attention on the radiant because the meteors near it will be travelling towards you and have extremely short trails.

Old Moon Shines with Venus and Saturn (pre-dawn)
2025-04-24 00:00
On Thursday morning, April 24, early risers can look low in the eastern sky for the pretty sight of the waning crescent moon shining a fist’s diameter to the right (or 10 degrees to the celestial west) of brilliant Venus. Much fainter Saturn will also shine a few degrees below Venus. Just before sunrise, Mercury will appear just above the horizon to Venus’ lower left. The moon and Venus, which will clear the rooftops around 5:15 a.m. local time, will make a lovely photo opportunity. Faint Neptune will not be visible.

Crescent Moon Meets Planets (before sunrise)
2025-04-25 00:00
After 24 hours of additional eastward orbital motion, the very slim crescent of the old moon will shine within a triangle composed of three planets before sunrise on Friday morning, April 25. Locate brilliant Venus and then look for the moon about a binoculars’ field of view (orange circle) to its lower left. Less bright Saturn will appear below Venus and to the right of the moon, while Mercury will be positioned about a fist’s diameter to the lower left of the two planets. You’ll need an unobstructed, cloud-view view to the east to see them from moonrise around 4:40 a.m. local time until the sky brightens enough to hide all but Venus. Observers closer to tropical latitudes will see the grouping, which will be oriented up-down, more easily.

Venus at Greatest Illuminated Extent (pre-dawn)
2025-04-27 00:00
On Sunday, April 27, Venus will reach its greatest illuminated extent for the current morning apparition. In a telescope (inset), the planet will show a surprisingly slender, 26%-illuminated, waxing crescent phase on a large apparent disk size of 39 arc-seconds. Even with a less than fully-illuminated disk, Venus’ distance from Earth of only 0.432 Astronomical Units (40.12 million miles or 64.57 million km) will boost its brightness to a brilliant magnitude -4.75. After rising at about 4:20 a.m. local time, Venus will be visible in the eastern pre-dawn sky below the western fish in Pisces and a few finger widths to the upper left of Saturn. Venus will appear nearly as bright on the surrounding mornings.

New Moon (at 19:31 GMT)
2025-04-27 17:30 - 19:30
The moon will reach its new phase on Sunday, April 27 at 3:31 p.m. EDT or 12:31 p.m. PDT or 19:31 GMT. At that time our natural satellite will be located in Aries and 3.25 degrees north of the sun. While new, the moon is travelling between Earth and the sun. Since sunlight can only reach the far side of the moon, and the moon is in the same region of the sky as the sun, the moon becomes unobservable from anywhere on Earth for about a day (except during a solar eclipse). On the evenings following the new moon phase, Earth’s planetary partner will return to shine in the western sky after sunset.

Venus Shines above Saturn (pre-dawn)
2025-04-28 00:00
In the eastern sky before dawn in late April, the orbital motion of the brilliant planet Venus will be carrying it past 240 times fainter Saturn. On the mornings before Monday, April 28, Saturn will be positioned several finger widths below (or 3.6 degrees to the celestial south of) Venus, allowing the two planets to share the view in binoculars (orange circle). After Venus shines closest above Saturn on Monday, it will descend more to Saturn’s left and widen their separation. All told, you’ll be able to see the duo in binoculars from about April 16 to May 6.

Crescent Moon Jumps Jupiter (evening)
2025-04-29 19:00 - 22:00
In the western sky after dusk on Tuesday, April 29, the waxing crescent moon will shine prettily a fist’s diameter to the lower right (or 11 degrees to the celestial northwest) of Jupiter. On the following evening, April 30, the moon will climb to shine a palm’s width to Venus’ upper right. The moon’s nightly shift across the stars and planets has long shown us that the moon is orbiting around Earth. The moon and Jupiter will make a lovely photo opportunity when composed with some foreground scenery before they set in the west around 11 p.m. local time.

The Three Leaps of the Gazelle (all night)
2025-04-30 20:00 - 2025-05-01 05:00
The large and bright constellation of Ursa Major, the Great Bear is at the zenith after dusk in late April. Everyone is familiar with the Big Dipper asterism portion of that constellation. Another easily seen, but lesser-known pattern is the Three Leaps of the Gazelle, composed of three pairs of medium-bright stars strung in a line spanning nearly 30 degrees of the sky. In each pair, the stars are separated by about a thumb’s width (or 1.5 degrees). The most westerly stars Al Kaprah and Talitha, are found by extending a line drawn diagonally through the Big Dipper’s bowl from Megrez to Merak, i.e., towards Castor and Pollux. The central pair of Tania Borealis and Tania Australis shines midway between the bright stars Dubhe and Ras Elased Australis in Leo. The lowest (most easterly) duo named Alula Borealis and Alula Australis, are close to a line extended to the right (celestial south) from Dubhe through Merak. The word Alula arises from Arabic for “first leap”, while Tania means “second”, and Talitha means “third”.

Minor Planet Vesta at Opposition (all night)
2025-05-01 20:00 - 2025-05-02 05:00
From time to time, the largest asteroids in our solar system become bright enough to be seen without special equipment by skywatchers. On Thursday, May 1, Earth’s orbital motion will carry us between the minor planet Vesta and the sun. On the nights around that date, Vesta will be visible all night long and shine at its peak brightness for the year of magnitude 5.4, which is well within reach of binoculars (orange circle) and small telescopes. Tonight, look for the asteroid as a medium bright speck located about two finger widths to the left (or 2.5 degrees to the celestial northeast) of the star Mu Virginis, which marks the lower toes of Virgo, the Maiden. Vesta’s trajectory over the rest of May will carry it retrograde westward between Virgo’s feet (red dotted line).

Neptune Lurks near Venus and Saturn (pre-dawn)
2025-05-02 00:00
In the early days of May, the brilliant planet Venus will be gleaming in the pre-dawn eastern sky near two other planets. Medium-bright Saturn will be readily visible a few finger widths to the Venus’ lower right (or celestial south), while far fainter Neptune will be located below Venus and a few finger widths to Saturn’s left. All three planets will be close enough to share the view in binoculars (orange circle). Observers located at southerly latitudes, where the planets will shine higher and in a darker sky, will have the best chance to see Neptune – but you will need a quality telescope to see its blue speck. On every morning after Friday, May 2, Venus’ easterly orbital motion will carry it farther to the left of Saturn and Neptune.

Half-moon over Mars and the Beehive (evening)
2025-05-03 19:00 - 22:00
In the western sky after dusk on Saturday, May 3, the reddish dot of Mars will be positioned just below the nearly half-illuminated moon. Binoculars (orange circle) will also reveal the scattered stars of the large open star cluster named the Beehive to Mars’ left (or celestial SSE). Other names for the cluster include Praesepe, the Manger, Messier 44 and NGC 2632. Tonight, skywatchers located in eastern Canada and the continental USA can watch the dark leading edge of the moon pass over Cancer’s medium-bright star Asellus Borealis “the Northern Donkey” shortly after 10 p.m. Eastern Time or 9 p.m. Central Time. Binoculars or a backyard telescope will help.

Mars Buzzes the Beehive (evening)
2025-05-04 19:00 - 22:00
During the first week of May, the eastward orbital motion of the planet Mars will carry it through the northern edge of the large, bright open star cluster in Cancer known as the Beehive and Messier 44. After dusk, you can locate the medium-bright, reddish dot of Mars shining about halfway up the western sky. Binoculars (orange circle) or a backyard telescope (green circle) will reveal “the Bees” sprinkled just to Mars’ lower left (or celestial south). Mars will approach the cluster from the right (celestial west) until Monday, May 4, when it will graze the outer part of the cluster. Every night after Monday, the cluster will move a little farther below Mars. The Beehive’s position close to the ecliptic allows it to be frequently visited by the moon and planets.

First Quarter Moon (at 13:52 GMT)
2025-05-04 19:00 - 22:00
When the moon completes the first quarter of its orbit around Earth at 11:52 a.m. EDT, 8:52 a.m. PDT, or 13:52 GMT on Sunday, May 4, the 90 degree angle formed by the Earth, sun, and moon will cause us to see our natural satellite half-illuminated on its eastern, sunward side. While at first quarter, the moon always rises around noon and sets around midnight in your local time zone, allowing us to see it in the afternoon daytime sky, too. The evenings surrounding the first quarter phase are the best ones for viewing the lunar terrain when it is dramatically lit by low-angled sunlight.

Moon near the Lion’s Heart (all night)
2025-05-05 20:00 - 2025-05-06 05:00
As the sky is darkening on Monday evening, May 5, Leo’s brightest star Regulus will appear just to the right of the waxing gibbous moon. That hot, white, B-class star, which is located only 79 light-years from our sun, marks the heart of Leo, the Lion. For skywatchers viewing the duo later at night, or in more westerly time zones, the moon’s easterly orbital motion will carry it farther from the star.

Eta-Aquariids Meteor Shower Peak (overnight)
2025-05-05 20:00 - 2025-05-06 05:00
The annual Eta-Aquariids Meteor Shower is produced when Earth’s orbit carries us through a cloud of particles left behind by repeated trips of Halley’s Comet along its own orbit around the sun. The shower, which runs from April 19 to May 28, will peak in intensity from Monday evening to Tuesday morning, May 6 in the Americas. A relatively bright moon will hide the fainter meteors until it sets around 3 a.m. local time on Tuesday morning. While some meteors should be visible on Monday evening, more should appear once the shower’s radiant point in Aquarius rises above the southeastern horizon around 3 a.m. local time on Monday. A few dozen meteors per hour are typical during the peak – including some fireball meteors. Its southerly radiant makes the Eta-Aquariids shower better for observers located closer to the tropics.

Bright Moon Approaches Spica (all night)
2025-05-09 20:00 - 2025-05-10 05:00
When the sky darkens on Friday evening, May 9 in the Americas, Spica, the brightest star in Virgo, will appear a short distance to the moon’s lower left – close enough for them to share the view in binoculars (orange circle). As the pair crosses the sky during the night, the moon’s orbital motion will carry it closer to the star and the rotation of the sky will shift Spica above the moon. Hours later, observers located within a zone extending southeast across the South Pacific from Micronesia, Melanesia, and southwest Polynesia almost to South America can see the moon occult Spica around 06:30 GMT.

Full Milk Moon (at 16:56 GMT)
2025-05-12 00:00
The moon will reach its full phase on Monday, May 12 at 12:56 p.m. EDT, 9:56 a.m. PDT, or 16:56 GMT. In the Americas, the moon will appear to be full on both Sunday and Monday night, but closer inspection will reveal a strip of shadow curving along the moon’s left and right limb, respectively, on those nights. Full moons in May always shine in or near the stars of Libra or Scorpius. The indigenous Ojibwe groups of the Great Lakes region call the May full moon Zaagibagaa-giizis, the “Budding Moon” or Namebine-giizis, the “Sucker Moon”. For them it signifies a time when Mother Earth again provides healing medicines. The Cree of North America call it Athikipisim, the “Frog Moon” – the time when frogs become active in ponds and swamps. The Cherokee call it Ahnisguti, the “Planting Moon”, when the fields are plowed and sown. Other common names are the Milk Moon, Flower Moon, or Corn Planting Moon.

Bright Moon Covers Antares (overnight)
2025-05-13 20:00 - 2025-05-14 05:00
When the still very full moon rises over the southeastern horizon in mid-evening on Tuesday, May 13, it will be positioned very close to the very bright, reddish star Antares, which marks the heart of Scorpius. As the duo crosses the sky all night long, the rotation of the sky will shift the moon to Antares’ lower left. Meanwhile, observers in a zone extending from easternmost Polynesia, east across southern South America and the tip of Antarctic Peninsula and over to the South Atlantic can watch the moon cross in front of (or occult) Antares. Lunar occultations are safe to watch with eyes, binoculars, and telescopes. Use an app like Starry Night or Sky Safari to look up the timings where you live.

Catch the Colors of Stars (all night)
2025-05-17 20:00 - 2025-05-18 05:00
Stars shine with a color that is controlled by their surface (or photospheric) temperature, and this is captured in their spectral classification. In mid-May every year, the three bright stars of the Summer Triangle asterism are climbing the eastern sky after dusk. Deneb, Vega, and Altair are A-class stars that appear blue-white to the eye and have temperatures in the range of 7,500 to 10,000 Kelvin. Arcturus, which dominates the southern sky in evening, is an orange, K-class giant star with a temperature of only 4,300 K. Chara, the fainter of Canes Venatici’s two stars, is a yellowish, G-class star with a temperature of 5,900 K, similar to our sun’s. Reddish Antares, the heart of Scorpius, which twinkles above the southern horizon, is an old M-class star with a low surface temperature of 3,500 K. You can estimate the temperatures of other stars by comparing their color to these bright reference stars.

Third Quarter Moon (at 11:59 GMT)
2025-05-20 19:00 - 22:00
The moon will reach its third quarter phase on Tuesday, May 20 at 7:59 a.m. EDT, 4:59 a.m. PDT, and 11:59 GMT. Third quarter moons always rise around midnight in your local time zone and then linger into the southern sky after sunrise. At third, or last, quarter, the moon’s western half is illuminated by the pre-dawn sun and the pole-to-pole terminator line becomes a straight line. The week of dark, moonless evening skies that follow this phase will be ideal for observing deep sky targets in binoculars and telescopes, especially spring galaxies.

Crescent Moon with Saturn and Neptune (pre-dawn)
2025-05-22 00:00
On Thursday morning, May 22, the pretty, waning crescent moon will begin its monthly cruise past the planets gathered above the eastern horizon. The moon will rise in the east during the wee hours of the morning. About 20 minutes later, the prominent, yellowish dot of Saturn will become visible several finger widths to the moon’s lower left (to its celestial east). The duo will share the view in binoculars (orange circle) while the morning sky brightens ahead of sunrise. The tiny blue speck of the distant planet Neptune will be positioned a generous thumb’s width to Saturn’s left (or 2 degrees to the celestial northeast), but it will be a challenge to see from mid-northern latitudes, where the slope of the ecliptic will keep the planets lower in the hazy sky. Early-rising skywatchers at southern latitudes, where the planets will be higher in a darker sky, will have a better view of the conjunction.

Old Moon joins Venus and Saturn (pre-dawn)
2025-05-23 00:00
After another 24 hours of easterly orbital motion, the old crescent moon will shine between Saturn and much brighter Venus on Friday morning, May 23. Their assemblage above the eastern horizon will offer a nice photo opportunity when composed with some interesting foreground scenery. Venus, the last of the trio to rise, will clear the horizon by about 4 a.m. local time. It will continue to gleam on the moon’s lower left until almost sunrise, but Saturn will fade from sight before then. If Friday brings clouds, don’t worry. On Saturday morning, the moon’s sliver of a crescent will be positioned to the left of Venus with Saturn off to their upper right.

The New Moon (at 11:02 pm EDT)
2025-05-26 19:00 - 22:00
The moon will officially reach its new moon phase on Monday, May 26 at 11:02 p.m. EDT or 8:02 p.m. PDT, which converts to Tuesday, May 27 at 03:02 GMT. While new, our natural satellite will be located in Taurus, and 4 degrees north of the sun. While at its new phase, the moon is travelling between Earth and the sun. Since sunlight can only shine on the far side of the moon, and the moon is in the same region of the sky as the sun, it becomes completely hidden from view from anywhere on Earth for about a day. After the new moon phase, Earth’s natural satellite will return to shine as a very thin crescent in the western evening sky.

See the Lunar X and V (peaks at 9 p.m. EDT)
2025-07-02 00:00
Several times a year near the moon’s first quarter phase, small clair-obscur effect features on the moon called the Lunar X and the Lunar V become visible in strong binoculars and backyard telescopes for a few hours. The Lunar X, a prominent X-shaped pattern, appears when the rims of the craters Purbach, la Caille, and Blanchinus are illuminated from a particular angle of sunlight (inset). Look for it beside the terminator about one third of the way up from the southern pole of the Moon. The Lunar V forms along the northern span of the terminator near the crater Ukert. On Wednesday, July 2 the features are predicted to start developing by about 9 p.m. EDT (or 01:00 GMT on Thursday, July 3), peak in intensity at around 10:15 p.m. EDT (or 02:15 GMT on July 3), and then gradually fade out toward midnight Eastern time. The event will occur during waning daylight for observers in western North America – but you can observe the moon in a telescope during the daytime, as long as you take care to avoid aiming it near the sun. The Lunar X will be visible anywhere on Earth where the moon is shining, especially in a dark sky, between 01:00 and 04:00 GMT on July 3.
