What’s Up in the Night Sky? – April 2021

Fred Barrett | Apr 07, 2021

My neighbours and I were walking our dogs this morning when they, as they often do, asked me if there was anything interesting going on up in the sky. I mentioned the medium size meteor shower going on later this month. It’s the annual Lyrid meteor shower. They asked me about the size of the meteors. A streaking meteor can be so bright and leave such a long trail. They must be huge they exclaimed. It surprised them when I answered that, in fact, they are quite small. They are made up of dust and ice and most vary from the size of a grain of sand to the size of a pea. The rarest and brightest, called fireballs, can be the size of a walnut. I explained that, although light is only a small fraction of the energy produced, it’s a good indicator of the amount of energy produced. That energy is equal to mass times velocity squared. So when you multiply a tiny mass (fractions of a gram) by a huge velocity squared (typically greater than 75,000 km/h), you end up with a huge amount of energy. Let’s say we double the mass. Then the brightness doubles. But if we double the speed, we quadruple the brightness. Speed is very important. Also, when the meteoroid burns up (ionizes) in the atmosphere, the colour of its streak indicates what makes it up. For example, oxygen appears green and sodium is yellow.

This year’s Lyrid shower is most active from April 14th to the 30th. It peaks on the morning of April 22. The radiant is above the bright star Vega in the constellation Lyra, the Harp, which is above the constellation Cygnus, the Swan. Cygnus looks like a large cross that form the wings and body of the Swan. It rises in the northeast about 10 pm mid month and swings south as the evening progresses. It is about 20 degrees high in the east by midnight and even higher in the southeast by 4 am. Early morning is best for observing. On the peak night of the 22nd, a gibbous moon may interfere with observing. A rate of 18 meteors per hour can be expected and that’s a good show. Don’t forget that the nights leading up to and following the peak night, are very good too. Find a nice dark site and enjoy the show. Have a look at Jupiter and Saturn low in the east as morning approaches.

In the evening sky, Mars, Venus and Mercury can be viewed in the west. Mars is high in the west at sunset in the stars of Taurus, the Bull, which is at the upper right of Orion. Venus and Mercury are low in the west and sink below the horizon quickly. Only Mars is left by midnight and it sets soon after. In early April, Saturn rises about 4 am and Jupiter follows soon after. They are best viewed later in the month when they have risen higher in the southeast sky. It’s a better time for following both planets’ moons as well. Binoculars are a sure fire help for observing and a low power telescope is a bonus.

This month in review: April 11: New Moon. April 14: The Moon is at apogee (max distance) – 403,762 Kms. Lyrid meteor shower begins. April 20: First quarter Moon. April 22: Peak of Lyrids. April 26: Full Moon. This Moon is called the Full Pink Moon. Native peoples named it after a pink flower that bloomed in April. It’s also known as the Full Grass Moon because, well, grass starts to grow. And no, it’s not that kind of grass. It’s also time to put away the snow blower and haul out the lawn mower for a tune up. April 27: The Moon is at perigee (closest) – 355,302 Kms.

Stay safe, stay separate and enjoy the sky. That’s a wrap. Keep looking up!

“The Beginner’s Observing Guide by Leo Enright is an invaluable companion for adventures in the sky. It also contains useful star charts. It can be ordered from the Royal Astronomical Society of Canada at www.rasc.ca/publications. A subscription to our very own excellent Canadian astronomy magazine “SkyNews” can be arranged at the RASC website as well.

Let me know how your observing has gone this month, especially anything unusual. I enjoy the feedback. If you have any questions or suggestions you can contact me through this paper or email me at This email address is being protected from spambots. You need JavaScript enabled to view it. . Clear Skies! Fred