by William J.Bechaver
EARTH — This weekend, we will have a rare opportunity to catch a glimpse of evasive Mercury.
Of all the naked-eye planets, though near, Mercury is often difficult to locate and view, due to its proximity to the sun. It is often lost in the glare of the sunrise before it can be spotted.
But this week we are given an opportunity, with some very visible pointers, to guide our way.
First of all, Mercury appears furthest from the sun, and best for viewing from Earth, this week. Also, on Saturday, September 16, Mercury and Mars will be very near each other. Less than a half a degree will separate the two, as viewed from Earth.
Though both difficult to see in the early morning glare, Mars will be much easier to locate, guiding our eye to the fainter Mercury.
So, less than an hour before sunrise, at about six o’clock, go out and look to the east. High above, you will easily spot brilliant Venus, a glowing gem in the dawn twilight sky. Look lower, toward the horizon, and you will be able to spot the faint pair of Mars and Mercury. The fainter of the two will be Mercury.
On the morning of Sunday, September 17, the moon will join the gathering, as it will lie just above Venus. Find the two, and draw a line directly down to the ground. About half way between Venus and the horizon, Mars and Mercury should be relatively easy to spot, before the sky becomes too bright.
The following morning, Monday, September 18, the moon will have sunk lower still, resting just above the coupling of Mars and Mercury, but even the slight crescent of the moon may be hard to spot through the sun’s glare if you wait too late.
So get out there early every morning this weekend for a spectacular view of the innermost planets as they come together with the moon to form some amazingly helpful groupings.
And let us not forget some of the NASA missions of note this week.
The Cassini mission, currently orbiting Saturn for the past thirteen years, will spectacularly come to an end on Friday, as it completes its final orbit of its ground-breaking and record-setting mission. The spacecraft will then plunge into the clouds of Saturn, ultimately burning up, as it sends us its final bits of information.
Also, the Voyager missions, launched way back in the seventies, are celebrating forty years of their exploration, as both are making their way further out of the solar system, and into interstellar space. They continue to operate, sending us back information of their locations. They are the furthest man-made objects from Earth.
And the Juno mission, now orbiting Jupiter, is settling in after its first year of exploration around the largest planet in our solar system, sending us information about the giant planet’s complex atmosphere and turbulent storms.
All three missions are passing milestones this week, and we will take a closer look at their discoveries, and the planets they have explored in the weeks ahead.
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William J. Bechaver is the director of SPACE • Spanish Peaks Amateur Cosmos Enthusiasts, the premier Astronomical Society for Southern Colorado and Northern New Mexico.