Mercury morning star worth getting up for, see where to look
Meteorologist/Science Writer
Monday, September 26, 2016, 1:27 PM - Early risers can see Mercury the morning star and evening skies show off a celestial lineup of three planets with a star thrown in as a bonus. It's the Night Sky this Week!
Mercury morning star
The closest planet to our Sun, Mercury, is peaking up over the eastern horizon before dawn these days, and this week, it reaches what's known as its "greatest western elongation."
This means that the planet is reaching the point in its orbit where it's the farthest west from the Sun in our sky, or in other words, its farthest distance from the horizon before it disappears into the glare of the Sun.
Looking east, predawn, from September 26 to October 2, 2016. Credit: Stellarium/S. Sutherland
You can see the planet trace a curved path - morning to morning - in the animation above, with its greatest western distance from the Sun on Wednesday, September 28, afterwhich it "loops" back towards the horizon.
A celestial parallelogram
If getting up pre-dawn to see Mercury doesn't fit with your schedule, this might be a bit easier on you. In the western sky, just after sunset each night this week, you can spot four bright objects in the sky, arranged in a parallelogram.
Looking west, post-sunset, for the week of September 26 to October 2, 2016. Credit: Stellarium/S. Sutherland
This includes the "celestial triangle" that's been in the sky for the past month or so - Mars, Saturn and Antares - and now it also adds in the planet Venus.
Since Venus is fairly close to the Sun, from our perspective right now, the planet sets fairly quickly after sunset. The best time to look for this is between the times of 7:30 and 8 p.m., local time, as that's when Venus will still be above the horizon and it will be dark enough to see at least Mars and Saturn, with Antares coming into view as the sky gets darker.
Once Venus sets, you will still be able to see the elongated celestial triangle for a few more hours, before those three objects set as well.
