Tomorrow morning might be a good time to call for extra celestial traffic control. A slip of a crescent Moon will join a passel of planets in the dawn sky for the first of several exciting conjunctions over the next few days.
In the space of three mornings beginning tomorrow, four planets, the Moon and the star Regulus will participate in six separate conjunctions. Here’s how it’ll play out. Time are shown in UT / Greenwich Mean Time and Central Daylight and 1° equals two full moon diameters:
Since several of the events occur in the middle of the afternoon for skywatchers in the Americas, here’s an expanded viewing guide:
* Thursday, October 8: Skywatchers will see Venus pass 2.5° south of Leo’s brightest star Regulus with a cool crescent moon a little more than 3° to the west of the brilliant planet. If you live in Japan and the Far East, you’ll see a splendidly close conjunction of the moon and Venus at dawn on October 9, when the pair will be separated by a hair more than one moon diameter (0.6°). At nearly the same time, the moon will be in conjunction with Regulus.
Observers in Australia and New Zealand will see the Moon occult Venus in a dark sky sky before dawn (or in daylight, depending on exact location) on the 9th. Click HERE for information, times and a map for the event.
* Friday, October 9: An even thinner moon passes about 3° north of Mars in the Americas at dawn and approximately 4° from Jupiter. Watch for the three luminaries to sketch a nifty triangle in the eastern sky 90 minutes to an hour before sunrise. Venus will gaze down at the planetary conclave 10° further west.
* Sunday, October 11: Mercury, which has quietly taken up residence again in the dawn sky, hovers 0.8° above a hair-thin moon this morning at 6 a.m. CDT. Best views will be about 45 minutes before sunrise, when the pair rises high enough to clear distant trees. Bring binoculars to help you spot the planet.
You’re thinking, why does this all have to happen in the morning? Thankfully, sunrise occurs around 7 a.m. for many locations, so you can see all these cool happenings in twilight around 6 a.m. — not terribly unreasonable. And now that the The Martian has finally hit the movie theaters, what better time to see the planet in the flesh? By pure coincidence, the location of stranded astronaut Mark Watney in the fictional account — Acidalia Planitia (Mare Acidalium) — will be facing dawn risers across the Americas and Hawaii this week.
Dare I say this string of continuous conjunctions is only a warm-up for more to come? Earth’s revolution around the Sun quickly brings Jupiter higher in the eastern sky, while Mars races eastward as if on a collision course. The following Saturday on October 17, the two will meet in conjunction less than 1/2 degree (one Full Moon width) apart. Very nice!
But it gets even better. On Tuesday morning, October 27, you’ll see all three planets huddle at dawn. One degree will separate Jupiter and Venus with Mars bringing up the rear several degrees further east. Feast on the view because there won’t be a more compact arrangement of three planets again until January 10, 2021.