October 2017 Night Skies
NASA’s Cassini spacecraft died September 18th just like it lived; spectacularly. With final commands from Earth, mission scientists sent the Saturn probe diving into the atmosphere to burn up like a metal meteorite.
Launched in 1997, the Cassini-Huygens craft took seven years to reach the ringed, gas giant Saturn. Initially the mission was to last four years. But NASA extended its tour of giant storms, rings and icy worlds twice discovering brutally cold, liquid methane seas on Titan and hydrothermal geysers of liquid water at Enceladus. Eventually, Cassini ran out of gas and NASA decided to crash the craft into Saturn rather than risk contaminating possibly life-bearing worlds of Enceladus and Titan.
Try imagining tiny Cassini diving between Saturn’s rings as you peer at planet in the evening. Saturn just passed aphelion; the farthest point in its 29.5 year orbit around the Sun, this past June. And it’s making an appearance in the western sky setting near 10pm mid-month. The rings are showing well at this point in its orbit. Bright Jupiter is sinking toward the Sun and sets at about 7pm. Venus and Mars dominate the morning sky rising just 30 minutes apart mid-month. After a spectacular lineup with Venus, Mars and the Moon in September, Mercury is lost in the solar brightness this month.
The Sun is producing its own interest this past couple of months. Our nearest star is passing into solar minimum; a period of relative quiet on the Sun where sunspots are few. But in the past few weeks, active sunspots as large as the planet Earth have excited scientists across the world. In fact, during some hazy mornings last week, I could just make out sunspots while taking sunrise photos. Some of these sunspots have unleashed some potent solar storms vcausing radio blackouts in high latitudes and aurora as far south as Arkansas.