The Sky Tonight: May 2025

THE CASUAL OBSERVER

May continues nan play of Djeran – nan play wherever nan cooler upwind begins. 

The cleanable nighttime to spell extracurricular this period is May 4, besides known as Star Wars Day (May nan Fourth beryllium pinch you). 

On this date, commencement your nighttime entity observations by looking to nan north-northwest wherever you will spot 3 pairs of absorbing things – Mars and nan Moon, arsenic good arsenic nan constellations of Gemini and Canis Minor, some identified by 2 easy-to-see stars. 

Caption: The bluish evening entity connected May 4.
Credit: Stellarium

The First Quarter Moon is nan brightest entity by far, and adjacent is nan fainter, reddish Mars. Scientists person precocious projected a caller exemplary for why Mars is red.

Instead of hematite (a ‘dry’ benignant of robust rust) scientists person recovered grounds of ferrihydrite, a ‘wet’ robust rust that has h2o locked up successful its molecular structure. This is much grounds suggesting that Mars erstwhile had awesome oceans connected its surface. 

To nan little near of Mars is nan reddish elephantine prima Pollux, successful Gemini. Pollux has a twin, called Castor, but they couldn’t beryllium much different.The single, enormous, reddish elephantine prima Pollux is thing like  nan six-stars-in-one strategy that we spot arsenic nan azygous ‘star’ Castor.  

If you clip your observations right, astatine precisely 7:13 p.m. connected May 4 you’ll spot a agleam ray moving crossed nan northwestern sky. Passing betwixt Castor and Pollux, it will descent nether nan Moon earlier fading retired of show successful nan bluish sky. That’s nary Moon, it’s a abstraction station. Specifically, nan International Space Station. 

Caption: Instantaneous location of nan International Space Station (blue box) astatine 7:13:44 p.m. connected May 4 

Finally, Canis Minor shines pinch nan agleam prima Procyon and nan fainter Gomeisa. These dress up nan assemblage of nan Small Dog successful nan entity and the companion to Canis Major.

Caption: Yeah, looks for illustration a canine to me.
Credit: Stellarium

Next to this spectacular sextuple is nan constellation of Leo, nan lion. A zodiacal constellation, Leo is 1 of nan fewer constellations that really benignant of looks for illustration what it is expected to represent.

Caption: Leo, nan lion, successful instrumentality figure. Moon and Mars for reference connected May 4.
Credit: Stellarium

After you’ve taken successful these nighttime entity delights, you tin either spell to furniture early aliases enactment up each night. Either way, nan Eta Aquarids meteor ablution puts connected a show earlier sunrise connected May 5.

Caption: Apparent location of nan entity of nan Eta Aquarids meteor ablution astatine 5am connected May 5. Venus and Saturn guideline nan way. 

This vibrant meteor ablution has agleam streaks that originate from nan illustrious Halley’s Comet. As Halley’s Comet moves done our Solar System connected its astir 75-year orbit, it occasionally passes adjacent capable to nan Sun to get basking capable for immoderate of its vulnerable worldly to boil distant into space. This ‘outgassing’ carries tons of ungraded and pebbles pinch it which are near free floating successful space. Eventually, immoderate of these pieces of ungraded collide pinch Earth and ray up our entity arsenic they slam into nan atmosphere, causing a meteor shower. 

The Eta Aquarids meteor ablution is not to beryllium missed. In bully conditions you should spot a meteor each infinitesimal aliases two. These meteors move fast across nan sky, and nan ablution really lasts each month. The champion measurement to spot it is to look to nan eastbound earlier sunrise connected May 5 aliases 6.If you hide to group nan siren connected these days, you tin effort again passim nan period of May. 

While you are watching nan meteor shower, you can’t not-see Venus. Fabulously agleam and dominating nan eastbound greeting sky, it makes for awesome viewing arsenic it glows against nan twilight of sunrise. 

At Scitech we get a batch of telephone calls and emails asking astir ‘the large agleam point successful nan sky’ during nan early greeting aliases evening, depending connected nan clip of year. It “seems to beryllium pursuing me.” It’s “there each morning. Almost achromatic it’s truthful bright.” These are each sightings of Venus. It takes its sanction for nan goddess of love, truthful named because it burns truthful bright.

This besides reminds me, I request to group my automatic replies:  

Caption: Sorted.  

ISS sightings from Perth 

The International Space Station passes overhead aggregate times a day. Most of these passes are excessively faint to spot but a mates of notable sightings* are: 

*Note: These predictions are only meticulous a fewer days successful advance. Check nan sources linked for much precise predictions connected nan time of your observations. 

If you are wondering why nan position disappears successful nan mediate of nan entity connected May 2, publication our article here. 

Moon phases 

May 4: First Quarter 

May 13: Full Moon 

May 20: Last Quarter 

May 27: New Moon 

Dates of interest 

May 4: Star Wars Day, Moon adjacent Mars. May 5: Eta Aquarids meteor ablution peaks earlier sunrise 

May 6: Eta Aquarids meteor ablution peaks earlier sunrise 

May 23: Moon adjacent Saturn and Venus 

Planets to look for 

Mars makes for decent viewing successful nan north-northwest this month. You tin spot it adjacent to nan Moon connected May 4 arsenic described above. 

Jupiter is visible for an hr aliases truthful aft sunset successful nan northwest. Catch it this period earlier it disappears down nan Sun. It will reappear successful nan eastbound entity earlier sunrise successful early July.

Caption: Mars and Jupiter successful nan northwestern evening entity connected May 4.
Credit: Stellarium 

Venus and Saturn are visible successful nan eastbound entity earlier sunrise. Venus dominates nan segment while nan fainter Saturn hangs a spot higher successful nan entity supra it. Mercury is besides there, person to nan horizon, but it moves down nan Sun successful nan second portion of nan period and gets mislaid successful nan glare. 

Venus and Saturn abstracted noticeably successful nan entity this month. Interestingly, this is nan other of what it looks like. It appears that Saturn is racing higher successful nan sky, and Venus is opinionated still, almost hovering supra nan horizon. What’s really happening is Earth’s activity astir nan Sun makes Saturn appear to move rather a lot. Not to beryllium outdone, Venus moves moreover faster, efficaciously ‘cancelling out’ nan activity of Earth and making it look to bent successful nan aforesaid place. This is overmuch much evident if you look astatine nan inheritance stars and comparison wherever Saturn and Venus are against them. 

Constellation of nan month 

Leo – The Lion 

Leo is simply a ample constellation visible successful nan bluish entity during Autumn. It is simply a very unique constellation whose stars shape an upside down mobility people sitting adjacent to a triangle and are collectively seen arsenic a lion. 

Caption: Leo, nan Lion, pinch nan mobility people (left) and triangle (right) easy discernible.  

In mythology, Leo is often seen arsenic nan Nemean Lion associated pinch nan communicative of Heracles (Hercules) and his 12 labours. The first labour of Hercules was to termination nan lion, a task made infinitely much difficult by nan truth that nan lion’s hide could not beryllium pierced by weaponry, rendering swords and spears useless. Problem solving connected nan spot, Heracles strangled nan lion pinch his bare hands, whereupon Zeus placed it successful nan entity arsenic Leo. 

The brightest prima successful Leo is nan magnitude 1.35 Regulus, meaning ‘little king’. This 4-star strategy consists of 2 pairs of stars orbiting each different and is nan namesake of Regulus Black from nan Harry Potter stories. One could reason that nan prima is amended described by its Arabic sanction Qalb al-Asad, meaning ‘the bosom of nan lion’.  

Leo also  includes nan Cosmic Horseshoe. This happens erstwhile you person 1 very distant inheritance postulation connected almost exactly nan aforesaid statement of show arsenic a foreground galaxy. 

Caption: The Cosmic Horseshoe.
Credit: NASA, ESA 

Einstein’s wide relativity predicts that nan gravity of a monolithic entity – for illustration a postulation – should crook nan way of ray arsenic it passes by. In this case, nan reddish postulation successful nan foreground (excitingly named LRG 3-757) has capable gravity to enactment for illustration nan lens of a magnifying glass, focussing nan ray from nan inheritance postulation successful a process called gravitational lensing. A flimsy misalignment from an nonstop statement of show leaves a mini spread astatine nan top, giving nan horseshoe appearance. A perfectly information lensed postulation is called an Einstein Ring. The effect allows america to adjacent astir nan foreground postulation to spot what is down it, albeit successful a very distorted view. 

Caption: Schematic sketch of gravitational lensing. Imagine this happening connected each broadside of nan monolithic entity and you tin spot really a ringing of ray is formed.
Credit: NASA 

Leo is besides location to nan Leo Cluster – a group of astir 70 galaxies bound together by gravity located astir 300 cardinal lightyears away. 

Caption: The Leo Cluster of galaxies and galore much distant inheritance galaxies. Apart from 2 stars, marked by horizontal lines, each different constituent of ray is simply a galaxy.
Credit: By Legacy Surveys / D.Lang (Perimeter Institute) & Meli thev – Own work, CC BY-SA 4.0 

Together pinch nan Coma Cluster – a postulation of astir 1000 galaxies located successful nan neighbouring constellation of Coma Berenices – they shape portion of a larger cluster of galaxies called nan Coma Supercluster. This is portion of an moreover larger cluster of galaxies called the Great Wall. Astronomers group clusters of galaxies together based connected their proximity and mobility done abstraction to amended understand nan large-scale building of nan Universe and really it sewage to beryllium nan measurement that it is today. 

Object for nan mini telescope 

The Leo Triplet – A cosmic trio of galaxies far, acold away 

The Leo Triplet is simply a throuple of galaxies adjacent together successful some statement of show and real-life proximity. Consisting of nan Hamburger Galaxy (yes, seriously) and nan Messier objects M65 and M66, nan Leo trio are each located astir 35 cardinal lightyears away.  

Caption: The Leo Triplet pinch M65 and M66 (top correct and mediate right) and nan Hamburger Galaxy (middle left). It does benignant of look for illustration a hamburger.
Credit: Chuck Ayoub – Own work, CC0  

A agelong clip ago, a adjacent brushwood betwixt M66 and nan Hamburger Galaxy severely distorted some of them. The huge, agleam streak trailing down nan Hamburger Galaxy, called a tidal tail, consists of worldly pulled from nan postulation by nan gravity of M66. 

Meanwhile, M66 shows evidently distorted spiral arms pinch much dusty worldly successful them and an different distribution of state compared to different galaxies. A awesome target for nan keen stargazer.