Let’s look at the ashen light of the Moon!

2024-01-17 17:10:02

Planet-wise, it’s starting to get difficult. Mercury is not visible. Venus is now low on the horizon after sunrise and will become increasingly difficult to observe in early February. Let us nevertheless note a rapprochement with a pretty lunar crescent on February 6 and 7 in the morning light. Mars is not observable. Jupiter remains the star of the Sky, still very bright in the constellation Pisces and clearly visible throughout the first part of the night!

Note two nice connections with the Moon, on the evening of January 18 and February 14. Concerning Saturn, the ringed planet is still visible after sunset in the constellation Aquarius, second half of January, and will be less and less observable in February. Finally Uranus is visible in a telescope not far from Jupiter and Neptune is difficult to observe.

Favorite for the ashen light of the Moon

Since there are no important astronomical events this month, let’s look at the ashen light of the Moon. I don’t know if you’ve ever paid attention, but when you have a nice crescent moon, it’s not uncommon to see the region of the Moon normally located at night slightly lit. It is this slight glow that we call ashen light. It is in fact the light of the Sun which reflects on the Earth and which illuminates the Moon. You will be able to observe it on February 11, 12 and 13. Camille Flammarion explained at the end of the 19th century that the intensity of ash light depended on the place on Earth where the light was reflected. If it is the ocean, the ashy light is weak, if it is clear regions, like the Sahara, like the winter snows, or like the clouds, it is more vivid. Today we know that it is above all the clouds which reflect this light. For the record, Benedetto Castelli, a disciple of Galileo, even thought he had highlighted, in 1637, the extent of the Australian continent by observing this clarity long before this continent had been geographically recognized.

Constellations

Like every year, in January and February, take advantage of the start of night to see high in the sky the constellations of Orion, Great Dog, Taurus and Gemini. I love this constellation of Canis Major, dominated by the majestic star Sirius, the brightest star in the sky. Under the Great Dog and Orion, I also invite you to discover smaller, lesser-known constellations such as the hare, the dove, the painter, the chisel, the sea bream or even the reticle. As you understand, these constellations do not appeal to the stories of Greek antiquity. This is normal because their names are much later and date mainly from the 17th and 18th centuries. To find these constellations, I remind you that sky maps visible from your country are available on the Astronomy Africa website in the section Observe the sky !

See you in February

A new astronomical telescope is once again in play thanks to our partners SSVI and RFI. To participate, send to our page Facebook Astronomy Africa your most beautiful photos or videos, or even a pretty text that you have written. The winner will be announced on April 15. I wish you a happy new year, good skies to all, and remember, the sky is the biggest screen, just look up.