April 2023 Astronomy Highlights: The April sky is filled with a wide array of spellbinding, mesmerising and breathtaking cosmic marvels. If one knows the time when a certain astronomical object will appear in the sky, and chooses the right venue with perfect visibility conditions, they will be able to witness beautiful celestial bodies this month. 


From Mercury in the evening sky to Lyrid meteors, the April sky will be adorned with stunning stellar bodies. 


Here is what you should look out for in the April sky and when. 


Mercury after sunset


On April 11, Mercury will be at its highest in the evening sky for the year, for everyone living in the Northern Hemisphere. In order to spot Mercury, one should look low in the west after sunset. 


Stargazers can start looking for Mercury from April 3, but the planet will be best viewed on April 11, because during these eight days, it will climb a little higher each evening.


The smallest and fastest moving of the planets in the solar system, Mercury is only visible in the sky for a few weeks every three to four months, because the rest of the time, it is too close to the Sun in the sky and is lost in its bright glare. 


Mercury is always near the Sun in the sky because the planet orbits extremely close to its host star. As a result, Mercury appears low near the horizon for no more than an hour or two, either following sunset, or preceding sunrise.


Some of Mercury's fleeting appearances are known as apparitions, NASA says on its website. These apparitions are better for observing than others, for various reasons linked with the hemisphere the observer is living in, and what phase the planet happens to be showing them at that time. The best viewing of Mercury's April apparition, in the Northern Hemisphere, is April 3 through April 11. 


After April 11, Mercury will quickly fade in brightness. This is because the phase Mercury will show Northern Hemisphere observers will become increasingly slimmer crescent. 


Venus near the Seven Sisters


In the evening of April 11, Venus will sit near the Pleiades star cluster, also called the Seven Sisters, in the west. The Seven Sisters, also known as Messier 45, are a group of more than 800 stars located about 410 light-years from Earth in the constellation Taurus. 


Venus and Pleiades will be close enough to appear in the same field of view through binoculars. On April 11 this year, spectators observing Venus and the Seven Sisters will see light that left the morning star about nine minutes earlier, whereas the light of Pleiades left the stars around 400 years ago. This is because Venus is 0.000018632 light years away from Earth, which means that light from Venus reaches Earth in 0.000018632 years, or 9.79 minutes. 


Moon near Saturn


From April 15 to 16, people can witness the Moon near Saturn low in the southeast, in the couple of hours before sunrise. The crescent Moon will rise with Saturn. 


Saturn is not the only planet Earth's natural satellite is making a close approach to this month. The Moon will make a close approach to two other bright planets in the sky: Venus and Mars. 


Moon near Venus


On the evening of 23rd April, the slim crescent Moon can be seen hanging just five degrees above Venus in the west after sunset. 


Moon near Mars


On the evening of April 25, the Moon and Mars will pair up in the sky, high in the west after dark. 


Phases of the Moon


On April 6, there will be a full Moon, followed by a third quarter Moon on April 13. On April 20, there will be a new Moon. 


Around April 26 and 27, the Moon will be at its first quarter phase, which means that Earth's natural satellite will appear as a "half-Moon". The half-Moon can be seen high in the sky after dark. 


Astronomy enthusiasts should try to observe the half-Moon with their binoculars or telescopes, because the first quarter phase of the Moon is the best time to observe the craters and Mountains on the lunar surface.


Lyrid meteor shower


April is the month when people around the world can witness the annual Lyrid meteor shower. This is a medium-strength shower that can produce up to 20 meteors per hour at its peak, under ideal conditions. 


In the pre-dawn hours of April 23, the Lyrids will peak this year. People can see a few shooting stars in the morning before and after the peak as well. 


Since the Lyrid meteor shower falls just a couple of days after the new Moon, Earth's natural satellite will not interfere with the Lyrids. Had the Lyrids coincided with the Full Moon or first quarter Moon, the glow of the moonlight would have overwhelmed the fainter meteors.


Named after the constellation Lyra, which is near the point in the sky where these meteor showers appear to come from, also called the radiant, the Lyrids are one of the oldest known meteor showers. 


The meteor showers originate as dust particles from a comet during its 400-year orbit around the Sun. The first recorded sighting of the Lyrids dates back to about 2,700 years ago in China. 


While the Lyrids tend to produce fast-moving meteors that lack persistent tails, they can occasionally produce a bright meteor called a fireball. People can get a clear view of the Lyrids from a place away from bright city lights. Observers must get horizontal, and look straight up, slightly away from the origin point, which is near the bright star Vega, in order to see the maximum number of meteors.