by William J. Bechaver
All summer long, we enjoyed magnificent views of all the visible planets arrayed across our skies. Now, one by one, we are losing them as we speed around the Sun, some falling behind, some outpacing us, and this week, a couple are lost to the Sun.
Earlier in the autumn, we lost Venus, as it passed between the Earth and the Sun. It has long since re-emerged in the early morning sky, now climbing higher with each passing day.
This week, two planets pass in conjunction with the Sun, and out of view from Earth.
The first is Jupiter, the largest planet in our solar system. Though it was directly overhead in the sky just a few months ago, the Earth has now outrun it, and is on the far side of the solar system from it.
Earth, being closer to the Sun, travels around much more quickly than does Jupiter. As a result, it has fallen far behind, as we pass around the Sun. This week, it will be directly opposite the Sun from Earth. On Monday, Jupiter will lie at an astounding distance of almost 600 million miles from Earth, or more than six times more distant than the Sun, with the Sun directly between Jupiter and Earth.
On the very next night, the smallest planet in the solar system will coincidentally be in conjunction with the Sun. Mercury, also being the closest planet to the Sun, travels around much more quickly than does the Earth. It is overtaking us in its orbit, and on Tuesday it will lie directly between the Earth and Sun, at a distance of just over 63 million miles, it is also the closest planet to Earth right now. On the day of conjunction, it will be lost in the sun’s glare, and also unviewable from Earth.
So, both Jupiter and Mercury will be in conjunction with the Sun this week, the smallest very close, and the largest very distant, neither visible from Earth. You may recall that it was a mere month ago that the two planets were in conjunction with each other, forming a nice pairing in the evening sky.
Now we have moved so the Sun is between us, and Mercury has moved between us also, making a direct line of the three planets and our star, Earth, Mercury, Sun, and Jupiter almost directly aligned.
Thanks for the positive feedback about our featured columns, and your continued interest in astronomy. If you have any questions or article requests, contact us at firstname.lastname@example.org, or follow us on Twitter @ColoSpacEScapE for updates and additional viewing opportunities.
• · William J. Bechaver is the director of SPACE • Spanish Peaks Amateur Cosmos Enthusiasts, the premier Astronomical Society for Southern Colorado and Northern New Mexico.