Caoimhín's Content

As we begin to come into April, I do need to mention Dark Skies and light pollution, as the first week of April is Dark Skies Week here in Ireland. The very last video I posted, an Irish language video, was all about light pollution and how much better the sky is without it, and soon there will be a video in English dealing with the same topic. I won’t focus on it too much in this video, but of course some things will be easier to spot in darker skies. It is almost impossible to avoid the topic of light pollution when discussing astronomy in the modern day, especially naked eye observational astronomy.

We will start at the start, watching the Sun se on April 1st and don’t worry, there will be no pranks from me. Jupiter will appear as the Sun goes down, very much in the West, practically above the sunset. Jupiter will soon be on the far side of the Sun from us, early April is really our last chance to observe it for a month or so. We will take a closer look at the largest planet in the solar system before it vanishes in another video. Even closer to the setting Sun, and vanishing even more quickly from our sky, is Mercury. The little planet is still technically visible at sunset in early April, but it is a tricky planet to spot even under perfect conditions. Mercury has passed its greatest elongation, so it is in a less than perfect position and won’t remain visible for even as long as Jupiter. Staying early in the evening with the orange glow of sunset visible, we can certainly see a variety of bright and famous stars. Betelgeuse and Rigel in Orion, Aldebaran in Taurus and the brightest one or two of the Seven Sisters or Pleiades. However, they are all very much to the West, and begin to set as the sky darkens. While these constellations dominated the winter sky, as we move now through spring and into summer they will vanish from the evening sky.

Before the sky gets too dark, the constellation of Aries should still be visible, about level with Jupiter in the sky. Just a little north of Jupiter is the bright star Hamal, the brightest in the constellation of Aries the Ram. The constellation of Aries doesn’t get a lot of attention, even its brightest star is a little tough to see, but it is on the ecliptic, just lower in the sky than Taurus at this time of the year. The bright star Hamal is, at the beginning of April, very close to the comet, C12P/Pons-Brooks. The comet is fainter than the star, and just a little to its left, a bit closer to Jupiter. As we move forward into April, the comet will appear to move towards Jupiter as it orbits the Sun, ending up just below Jupiter around the 10th of April. As we move through the dates, we will see that the comet is quite close to Jupiter already by the 8th, the date of the solar eclipse. There will be a video about that eclipse soon, and it will deal with the comet and its visibility. As we take a closer the look the planet Uranus becomes visible, as it would with the help of a binoculars or telescope. A few days after the eclipse on the 10th, the Moon has moved past new, bringing it right next to Uranus and Jupiter, all three of them together just a little higher in the sky than the comet 12P/Pons-Brooks. It will be tricky to see, as all three objects will be very much in the glow of sunset, and as the sky darkens, they will get closer to the horizon, making them more likely to be blocked out by objects on the ground.

As we finally push into darkness it gets to around 10 o’clock on April 10th. We are definitely getting in towards summertime now, so the days are getting longer and the sunset later for those of us in the Northern Hemisphere. By the time it is dark we can see that Orion’s already close to setting and Taurus and the Seven Sisters are following the Sun under the Western horizon. Leo is now the constellation dominating the southern sky early in the night, with almost all of the constellation of Virgo covering the arc of the ecliptic down into the East. We’re going to start seeing more of Virgo as we move into April as well. Pushing through to the end of the month, up to the night of the Full Moon on April 23rd, the Moon will be towards the end of the constellation of Virgo. We appear to be seeing this Full Moon at 100% full as it rises, something that you may know is not guaranteed from my previous videos. By the night of the Full Moon, Mercury is long gone from the evening sky, Jupiter has vanished, and Orion is already setting while the glow of sunset still brightens the sky.

Evening moving later into the night, the sky isn’t going to get incredibly dark on the night of the Full Moon, the Full Moon itself will provide too much light. By the end of the month, even just past midnight, Leo is already moving Westward of the Southernmost point in the sky. Closer to due South, and lower, is the little constellation of Corvus the Crow, a nice diamond shaped constellation which will be just above the horizon at the time showed in the video. We can see that the Full Moon is close to the end of Virgo, it’s passed the bright star Spica, the brightest star in the constellation of Virgo. You might remember from a previous video that there are a lot of galaxies out the direction of the end of Leo and the start of Virgo, and as we move through April Virgo will be up earlier and earlier, making those galaxies easier to observe. However on the 23rd/24th, faint objects like galaxies will be harder to see due to the Full Moon. Continuing through to the very end of April, the sky is going to be free of the Moon little bit longer during the early part of the night, but of course as we push up towards morning time the Moon will come back into view as the Sun is rising.

Very much at the end of April, as the Sun rises on the 30th, two planets will be above the horizon just as the Sun rises, Saturn and Mars. Mars is still ahead of the Earth and moving in the same direction we are, away from us. The Earth is moving around the Sun faster than Mars, so we will catch up and when we do we will begin to see Mars moving across our sky and into the evening sky, but we aren’t quite at that point yet. Saturn, orbiting the Sun much more distantly and much slower, it is already further out from the Sun in our sky and will reach an easy position to observe much earlier, but still a little after April. From the city, Mars is still going to be so close to sunrise as to be almost invisible, but it should be easier to see from a darker location. Removing the light pollution lets Mars appear as a bright dot surrounded by the glow of sunrise at about 5:15 in the morning. In a dark sky like this, we can clearly see the teapot shape of Sagittarius the Archer above the horizon almost to the South, very near Scorpius and the bright red star Antares. We can also see the Summer Triangle, much higher and a little to the East. The Summer Triangle, is coming up in the morning, but we’re not in summer yet so it won’t be there all night. You may remember that the glow of the Milky Way stretches through the Summer Triangle, and that the core of the Milky Way is just between Sagittarius and Scorpius. Earlier in the morning, before the glow of sunrise blocks it out, the Milky Way will be visible here.

Making that jump back to about 3 o’clock in the morning in late April and that lovely glow of the Milky Way appears. The center of the Milky Way will appear closer to sunset as we move into summer, but of course the days will start getting longer and the galaxy won’t be out for as long. Moving back into April to the night of the Full Moon, we can see that the light of the Moon is Certainly enough to obscure the glow of our galaxy, even making the bright core more difficult to spot. The night of the Full Moon is unfortunately also close to the night of the peak of the April Lyrids meteor shower. This meteor shower will peak on the 22nd of April this year, just a few days before the Full Moon, and the extra light will obscure fainter meteors from view. The April Lyrids can be a pretty good meteor shower, with a zenith hourly rate of up to 60. 60 meteors an hour passing through the highest point of the sky is certainly a lot more than the 10 or so we get on average, but that high rate only occurs on the best years. This year, it looks like we will have a ZHR closer to 20, which would be less impressive even on a moonless night. Then again, any meteors you do manage to see will be the ones bright enough to shine through, and there may still be some visible in darker locations. Just before the Moon reaches Full, on the morning of the 23r of April especially, it will come very close to the bright star Spica. The Moon won’t block out Spice, at least from Ireland this won’t be an occultation, however it is a very very close conjunction, especially in the morning as the Moon and Spica begin to set. They will be pretty lose together early in the night, but the motion of the Moon around the Earth will bring them even closer together by morning time.

As I hope you have now seen, we have a few exciting things coming up in the month of April. The Milky Way is getting easier to see in the morning, Saturn and Mars begin to come back into the sky, there’s the comet 12P/Pons-Brooks, which is only visible every 71 years, and that’s for those of us who aren’t lucky enough to see the solar eclipse on the 8th of April. All of those objects look even better under dark skies and with it being Dark Skies Week next week you have some great reasons to travel into the countryside and look into the night sky. There will be another video all about light pollution, one dedicated to the solar eclipse and a video taking a close look at Jupiter before the month is out. If you don’t want to miss those, you subscribe to this website or the Caoimhín’s Content YouTube channel, or both, so you get notified when I post them. I will also show what’s coming up in the sky for the following month every month, along with one off videos on various topics, so if you are interested then make sure to pop back next time.