Mars plays tag in the night sky
One would not expect the planet named for the Roman god of war to be so playful but, in the coming weeks, Mars continues its playful game of “tag, you’re it!” with its fellow planets.
The red planet will have its third planetary conjunction of the year on May 17 with the planet Neptune, followed by a fourth conjunction May 28 with the planet Jupiter.
On March 16, Mars played tag with Venus and, on April 5, had a game of tag with Saturn.
As you may remember from past articles, a conjunction (what I like to call a game of celestial tag) occurs when two or more celestial objects, most often planets (referred to as a planetary conjunction), appear to pass each other in the night sky as seen from Earth.
Technically speaking, astronomers define a conjunction as when two or more celestial objects share the same right ascension or ecliptic longitude.
It should be remembered that a close approach (the small angular separation of two celestial objects, as seen from Earth) is not necessarily the same as a conjunction. For a conjunction to occur, one of the objects must pass to the north or south of the other object as viewed from Earth.
The angular distance between objects as seen from Earth during a conjunction usually varies between 0.5 degrees and 9 degrees, although it can be much smaller, as with the breath-taking Great Conjunction between Jupiter and Saturn on Dec. 21, 2020, when the two planets, came within 0.1 degree of each other (as seen from Earth), appearing to the naked eye as a single star in the night sky.
Conjunctions are optical illusions, as the celestial objects taking part in the conjunction are, in reality, many millions of kilometres apart in space.
The actual conjunction between Mars (magnitude +0.8, in Aquarius — the Waterbearer) and Neptune (magnitude +8.0, in Aquarius), unfortunately for observers in the western hemisphere, occurs during the daytime period of May 17, when Mars slides 0.5 degrees south of Neptune.
However, during the pre-dawn hours of May 18, weather permitting, observers will be able to spot Neptune just to the upper right (northwest) of Mars. You will need binoculars or a telescope, and a clear, cloudless view of the sky above the southeast horizon.
Neptune, about 1/700 the brightness of Mars, will be the bluish star at about the two o’clock position relative to Mars.
If you are having trouble locating Mars, first locate Jupiter (magnitude -2.2) above the eastern horizon (see below). Mars will be sitting to the upper right (southwest) of Jupiter, with Venus (magnitude -4.0) to Jupiter’s lower left.
Although not a truly mindboggling event as far as celestial events go, for those amateur sky watchers among you who have never seen the planet Neptune before (it is, in truth, an extremely small and dim planet as seen from Earth, even in large telescopes), this is an excellent opportunity to cross this planet of your planets viewed list.
Mars will have another conjunction this month, this time with the planet Jupiter on May 28. I won’t go into detail about this conjunction here, but will remind you of it in next week’s column. Of course, if you are anxious to know about that conjunction before then, you can simply Google Mars-jupiter conjunction, May 28, 2022.
You can also find a more detailed account of the May 17 Mars-neptune conjunction by typing in Mars-neptune conjunction, May 17, 2022.
THIS WEEK’S SKIES
Mercury, approaching inferior solar conjunction, is not visible this coming week. Saturn (magnitude +0.8, in Capricornus — the Sea Goat) rises in the east-southeast around 2:30 a.m., reaching a height of around 20 degrees above the horizon before fading with the break of dawn around 4:55 a.m.
Mars rises in the eastern sky around 3:40 a.m., reaching 13 degrees above the horizon before fading into the morning glow by about 4:50 a.m.
Jupiter (magnitude -2.2, in Pisces — the Fish) follows Mars into the pre-dawn eastern sky by 3:45 a.m., reaching an altitude of about 15 degrees above the horizon before it, too, is lost in the light of the approaching dawn by about 5:15 a.m.
Venus (magnitude -4.0, in Cetus — the Sea Monster) clears the eastern horizon around 4:20 a.m., reaching only nine degrees above the horizon before succumbing to the dawn’s light by 5:15 a.m.
As mentioned in last week’s column, the full Super Flower Moon, at perigee (closest approach to Earth), will rise into the late evening, eastern sky on the 16th, as the Sun sets in the west. Hopefully, some of you had the opportunity of witnessing at least some portion of the total lunar eclipse during the overnight period of May 15-16.
Until next week, clear skies.
EVENTS
• May 16: Full Super Flower Moon at perigee, total lunar eclipse; pre-dawn.
• May 18: Mars-neptune conjunction; ESE, pre-dawn.
• May 22: Last quarter moon; Saturn four degrees north of Moon.