By Brian Fenerty
Tiny Mercury was hard to spot over the Purcells, so pale in the sunset, but there it was a very subtle object compared to brilliant Venus.
Mercury, as always, is moving very quickly. Soon in line with the Sun, it will set at the same time. Venus, however, is well-situated to remain a highlight in the western sky into summer.
Meanwhile, overhead, Jupiter is falling behind us in its orbit so bit by bit it appears closer to the Purcells, visually looking closer and closer to Venus by the summer.
Also bit by bit, Saturn is climbing in the southeast into the middle of the night sky. Not as bright as Jupiter, but always enjoyable to detect its rings in binoculars or telescope. Even if not enlarged much, seeing Saturn directly again through an eyepiece makes for a special emotional re-discovery.
Continuing my column series discussion about the New Horizons space probe hurtling towards its Pluto fly-by in July, the probe is now close enough to stare ahead looking for possible hints of dust or debris around Pluto.
NASA may consider changing course slightly to avoid such potential hazards around Pluto. And taking standard photos is not the only thing New Horizons will be doing, with a wide variety of instruments on board. More on that next column.
The visual alignment of planets (such as the Moon, Venus and Mars a few months ago, or Jupiter visually next to Venus this summer) has an interesting subtle connection.
Over the years and centuries, the recurring patterns of planets aligning themselves next to each other, or at 90 or 120 degrees to each other, long fascinated humans.
Often their possible connections to earthly matters and human affairs were formulated this way and that to try to give chaotic life on earth more pattern, too.
Modern astronomers say such astrological connections may stand up to wishful thinking, but not to actual rigorous testing. If we are talking direct gravitational effects on newborns, then objects like our moon or obstetricians have a much closer, much bigger effect!
However, if we look at how planets including Earth interact with each other, we do start to see genuine subtle effects. Planets wobble over thousands of years (i.e. our own north star Polaris isnt always our north star!) and while a wobble continues, it gets shifted, gradually, by the other planets.
Earths orbit around the Sun is not a perfect circle that, too, changes over long periods caused by other planets. How do such interactions affect Earth and our climate? Maybe even we individuals? The key word is subtlety. More next column!
Brian Fenerty is a member of the Royal Astronomical Society of Canada. Contact him at email@example.com.