February 9 – 22, 2015
Especially alluring these mid-February weeks are the celestial events during the hours of dusk and dawn. Planet Venus appears half an hour, or less, after sunset: it is so luminous that its star-like light penetrates Earth’s atmosphere when the sky is still pale blue in the west-southwest. As twilight deepens the planet reveals to us why it is named for the goddess of love and beauty. All the while it can be seen from indoors if you have a west-facing window.
the planets approach each other from the 9th – 21st.
Courtesy EarthSky.org
Turning opposite, to the east, we see Jupiter beam at its brightest for the year, although second in brilliance to Venus, the most luminous celestial object after the sun and moon. To Jupiter’s right shines the brightest true star seen from Earth, aptly named Sirius, which is Greek for “scorcher.” It is the outstanding star in the constellation Canis Major, the Great Dog, prominent through the winter at Orion the Hunter’s side in the nighttime sky.
The planets in our solar system are visible because they reflect the light of our sun, whereas true stars are suns far beyond our solar system. Sirius is one of the closest stars to Earth. With a clear, panoramic view close above the horizon at dusk, from east to west we would see Jupiter in the east, Sirius southeast, and Venus in the west-southwest, as if strung along a loose string.
In deepening twilight, above Venus the planet Mars emerges, with its dim but steady, rusty-gold to orange light. The two planets appear closer together each evening, an exquisite show culminating on the 20th when a waxing, eyelash crescent moon joins the pair the day before their closest approach. The dance continues through the 23rd. Mars and Venus appear side by side, then switch positions in good do-si-do fashion. Venus gradually separates from Mars, ascending higher in the evening sky.
Venus is known as the Evening Star and the Morning Star. It is not an all-nighter; rather it follows sunset or precedes sunrise in a predictable rhythm. Currently, as Evening Star, Venus is visible for about two hours, disappearing into the western horizon shortly after nightfall. Jupiter travels the sky all night. When we awake at dawn we discover the same planet setting in the west-northwest.
Looking to the opposite horizon at dawn, planet Mercury appears in the east-southeast about mid-month. A wisp of a waning crescent moon rises in the east-southeast with Mercury at 5:30 a.m. on the 17th; sunrise follows soon after, at 6:48. The best chance of seeing this delicate pairing might be from 6 – 6:15, before the rising sun’s light washes out the thin moon with the small planet to its right. Gaze just above the east-southeast skyline.
Note that on the 17th Mercury pairs with the last crescent moon in the morning before new moon, when the moon is dark, on the 18th, whereas Venus and Mars are joined on the 20th by one of the first evening crescent moons of the new lunar cycle.
Addendum: An introduction to the elusive Zodiacal Light follows for the avid sky watcher. The basic conditions are right to observe this beautiful phenomenon, although some conditions may not be attainable for everyone.
Excerpted from Starry Night Educator Geoff Gaherty’s column at Space.com:
“So to see the Zodiacal Light you first of all need to get away from light polluted urban skies. You need to observe at the dark of the moon, such as we will experience…… [until the 20th]. Finally, you have to choose the right time of the year, when the ecliptic is close to rising vertically in the sky, normally in February and March in Northern Hemisphere evenings. You also need to give your eyes at least 20 minutes in total darkness so that they reach their maximum sensitivity.”
To get the full story, click here.
