by William J. Bechaver
EARTH — This week we had a rare opportunity to view Mercury when it is closest to us.
Last month, Mercury was lost in the glare, as it began to pass between the Earth and the sun. Usually, we wouldn’t be able to see the tiny planet until it re-emerges from the glare. But this year, we enjoyed the rare circumstance when we actually can see Mercury as it passes in front of the disk of the sun. This perfect alignment is rare, when we can actually see Mercury at the moment it lies directly between us and the sun, and is therefore at it’s closest position to the Earth.
Adversely, Venus was also lost in the sun’s glare. But it lies much further away, as it is on the opposite side of the sun, at the greatest distance in it’s orbit, and the furthest it can be from us.
Miraculously, with tiny Mercury nearest to us, and with Venus at it’s furthest point, the two planets appear generally the same size right now, as viewed from Earth. It is impossible to appreciate this fact, as both are impossible to view with the naked eye, due to their size, and their proximity to the sun.
Amazingly, Mars is also very near a point of opposition, which means it is directly opposite us from the sun, or highest in the sky in the middle of the night. This also places Mars the closest to Earth it will be this year.
So, with Venus at it’s furthest point, and Mercury and Mars at their closest, this means that the four inner-most planets are basically in a straight line with the sun. This is a rare occurrence indeed.
Though amazing, the alignment of the inner planets is hard to observe, especially with two of the players lost to the sun. Mars is at it’s nearest and brightest in the next couple of weeks, and we’ll observe it with the moon next week.
For our observing pleasure, Jupiter once again makes a great pairing with our moon this week. On the evening of Saturday, May 14, go outside at almost any time. It’s always easy to look up and find the moon. A mere two degrees north of the moon will be mighty Jupiter, the next nearest planet beyond Mars, and the largest planet in our solar system. Though Mars is much nearer, Jupiter will always outshine it while we are on the same side of the sun.
We’ll also explore the apparent sizes of the planets as they appear from the Earth, and why some smaller ones outshine the brighter next week, as we appreciate the placement of the planets this week, as everything seems to be in nearly perfect alignment. Thanks for the positive feedback about our columns, and your continued interest in astronomy. If you have any questions or article requests, contact us at
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We are SPACE, Spanish Peaks Amateur Cosmos Enthusiasts.