“What is it like to be passed, in the cold and the still of the night, by a ghost 10,000 times the size of the Earth?”
The above is a quote from page 3 of my 1996 book “Comet of the Century.” It was based on an experience I had exactly 35 years ago when here in Cumberland County I witnessed in early May one of the clearest, darkest nights in my life. These sky conditions enabled me to trace that vast “ghost” — the tail of the departing Halley’s Comet extending tens of millions of miles — out to more than one-quarter of the way across the sky.
I’ll return to this Halley anniversary at the end of today’s column. But first let’s preview the sights of moon and planets we can look for these next two weeks.
Four nights of moon-planet pairings. Tomorrow morning, before dawn, the bright point of light well to the upper right of the crescent moon is the planet Jupiter. Fortunately the moon’s encounters with three other planets — next week — are all visible in the convenient hours right after sunset.
On Wednesday, May 12, the month’s most spectacular pairing of moon and planet occurs. This marvelous event is the very close “conjunction” of an extremely thin moon with Venus. How thin will the moon be? It will be just 29 hours past the invisible New Moon phase and only a bit more than 1% illuminated. The best time to look for the moon-Venus duo on the big night will probably be around 8:30 p.m. You will have to have an unobstructed view down to very low in the west-southwest to see the two worlds then. The lunar crescent’s points should be directed slightly left of straight up. And only about 1½ apparent moon-diameters to the right of the moon will be Venus’ bright point of light. If there is strong horizon haze present you may need to use binoculars to glimpse the low, dimmed pair.
Venus is returning to evening visibility after a year before dawn and will be getting higher in the months ahead. But the planet that the lunar crescent visits on Thursday, May 13, only peeks into visibility in the dusk for a few weeks at a time.
That planet is Mercury and you can look for it close to the right of the moon that night. Venus is setting well to their lower right a little after 9 p.m. but the moon and Mercury set around 10 p.m.
We now skip ahead to Saturday, May 15. Wait until about 9 p.m. and then start looking for a modest point of light not far to the upper left of the moon. That’s Mars. And on Sunday, May 16 the moon lies in a nearly straight line with two stars that are currently a bit brighter than Mars: the Gemini twins, Pollux and Castor (Pollux is the star appearing closer to the moon).
Halley’s Comet + 35 years. Now let’s return to the Halley’s Comet anniversary we mentioned at the start of the column. The 1985-86 return of Halley’s Comet may have been its least bright in about 3,000 years (the comet didn’t get close enough to Earth). But it was a naked-eye object for about 7 months and on that gloriously clear evening in May 1986 I was able to trace its tail out to 50° long (that’s five widths of your fist held out at arm’s length).
Halley’s Comet is not quite out to its far point so we have another 40 years to wait before it returns to sun and earth with a brighter display — in 2061.
This month brings us several other interesting space anniversaries, by the way. On May 5, exactly 60 years ago, Alan Shepard became the first American to reach space.
On May 11, exactly 38 years ago, a small comet passed closer to Earth than any had in over 200 years. That was another night in early May when New Jersey’s ultra-clear weather allowed me the best view in the world of an historic comet.
Fred Schaaf is a local author and astronomer. He can be reached at email@example.com.