The Planets
Planet Data For May
Click on any planet below to go straight to its section.
The table below shows key data for the planets this month, including rise, transit and set times, as well as magnitude, apparent size and position data (right ascension and declination).
Events that occur when the sun is below the horizon are shown with a black background and white text. All other events happen when the sun is in the sky and other for not visible for observation.
This May is not great for planetary observers. Venus is the only decent evening option, with Mars being too small to enjoy anymore. All the other planets are best seen in the morning, and Saturn is the only one against a dark sky.
Jupiter, Mercury and Neptune are putting distance between themselves and the sun, but a shallow ecliptic and early sunrise are making for poor observing. Uranus is not visible at all this month as it passes behind the sun on 09 May.
All of the images below can be opened full screen in a new tab by clicking on them
Mercury
05th May
Mercury is moving away from the sun but is too close to see it yet. This is the view at just after 6am.
15th May
At 05:45, you can see how shallow the ecliptic is. Mercury is far from the sun but not high above the horizon at sunrise.
25th May
Mercury is four days from its maximum distance from the sun, but is only 6° over the horizon shortly before sunrise.
We are at the whim of the ecliptic this month. As you can see from the images above, the line that the planets follow (the ecliptic) is so shallow that Mercury is barely above the horizon shortly before sunrise, even when it is at its farthest from the sun.
Contrast this with the evening views we had in March, when the ecliptic was much steeper to the horizon. Mercury was just as far from the sun but rose more than 10° over the horizon.
In summary, not great views this month. The same will be true next month as the smallest planet travels back towards the sun.
Venus
05th May
Venus is high and easily found at 9:30 pm due to its brightness. Other than the moon, it’s the brightest night sky object.
15th May
This view is also at 9:30 and the planet is more than 25° above the western horizon.
25th May
Your telescope will reveal a disc that’s just over half illuminated this evening and 21 arcseconds wide.
This month is great for spying on Venus. The disc grows in size as it moves closer to us and yet, at the same time, the amount of it that’s illuminated shrinks, so its overall brightness remains the same dazzling -4.1/-4.2.
At the start of May, Venus is 17 arcseconds wide and 66% illuminated – looking like a mini version of the gibbous moon at your eyepiece. When 31st May ticks around, the planet will appear close to 23 arcseconds across (a 30% increase in size over the course of the month), but is only just over half illuminated.
In early June, Venus will be as far from the sun as it gets (maximum elongation) and then starts to travel back towards it. All the time, the proportion of the disc that’s illuminated will shrink as the disc itself gets larger.
Mars
05th May
At 9:30 pm we can see Mars near the twins of Gemini. It’s high and easy to find with its reddish hue, but is too small to see details.
15th May
Ten days later, Mars is one-third of the way over the western horizon.
25th May
Mars has left Gemini behind and entered Cancer and closing in on M44.
The Red Planet is about as small as it gets night, with its disc smaller than five arcseconds wide. It’ll shrink to just 3.7 arcseconds wide, making it almost as small as Neptune, before it starts to grow again in the middle of October.
Sadly, there is not much to see through our telescopes on the Martian surface before the last half of 2024.
Jupiter
05th May
At 6 am, Jupiter has already broken the eastern horizon, but the sun is still some way behind.
15th May
It’s 5:30 am and we can see distance between Jupiter and the sun but the shallow ecliptic means it’s not great viewing.
25th May
The same is true at 5 am today, Jupiter is only 6° over the horizon but dawn is already brightening the sky.
Jupiter has returned as a morning planet but there are no great views to be had just yet. As we saw with Mercury, the ecliptic is so shallow in the morning that the largest planet is only a few degrees above the horizon when sunrise is due, even though it has travelled far from our star.
We’ll have to wait a few more weeks, and be prepared for early alarms, to have more rewarding Jupiter observing sessions.
Saturn
05th May
Saturn is ‘ahead’ of Jupiter in its race away from the sun, so we do now see it against a dark sky. This is the view at 5 am.
15th May
Also 5 am, and a hint that dawn is just around the corner, but Saturn is 16° high in the southeast.
25th May
23° high now, but we need to see it at 4:30 am for this view. The disc is 17 arcseconds wide.
Saturn begins to deliver decent views once again this month, but only for those of us prepared to set the alarm for ealy o’clock. By the end of May, we can see it high in the southeast while the sky is still dark.
As Earth and Saturn steadily move closer together, its disc grows to larger than 17 arcseconds and shines at magnitude 1.0.
Uranus & Neptune
15th May – Uranus
Just days after passing behind the sun, there is no chance to see Uranus this month. This view is at 6 am.
15th May – Neptune
At 5 am, we see Neptune near the moon. It is low to the horizon, about 14° here, and too close to dawn for great viewing.
Our two most distant planets don’t offer good viewing this month. We can’t see Uranus at all because it passes behind the sun on 09 May. Neptune is starting to put some distance between it and our star, but the shallow ecliptic and early sunrise mean that there’s not much to see yet.
All Planets Viewer
Use the table below to see when each of the planets is observable for each day this month. Click on it for full screen.
A planet is classed as observable when it is more than 10° above the horizon and the sky is dark enough for it to be observed.
Planet ephemeris tables produced with the kind permission of Dominic Ford. Sky images are courtesy of SkySafari Pro 6.