You’ll need a small microscope to see Neptune and binoculars to see Uranus, but a rare panorama of planets will adorn our skies this summer.
The interesting planetary slow dance before sunrise continues during June.
At 4:30 a.m. earlier this month, Venus will be at ESE, about 6 degrees above the horizon; Mars and nearby Jupiter are about 15 degrees high and Saturn is about 20 degrees, aligned at an angle of about 30 degrees to the horizon west (right) of the sun. By the end of the month, Jupiter will have moved west and up about 30 degrees above the SE horizon and Saturn about 26 degrees above the south horizon. This line of planets is quite close to the ecliptic, the path we see the sun make through the sky as we orbit it. Although most planetary orbits are slightly inclined toward the ecliptic, they remain fairly close to the plane of our orbit.
Being able to see four visible planets online is awesome, but what strikes me even more is that with binoculars you can also find Uranus about 40 percent of the way from Venus to Mars. With a small telescope you can also see Neptune about 30 percent of the way from Jupiter to Saturn. Uranus is just below the naked eye in the magician. 6.6 and Neptune is weaker with only about 8.2. So this is almost every planet in the solar system since Pluto was voted off the island a few years ago. The only thing missing is Mercury, which passed through the lower conjunction – between us and the sun – on May 21st. Wait until mid-June, however, and Mercury will begin to appear above the morning horizon just north-east, below, and to the left. of Venus. Although the two outermost planets, Uranus and Neptune, are in line, they are not in order to the right of Saturn. However, the planets with the naked eye, Mercury, Venus, Mars, Jupiter and Saturn, from the inside to the outside, are in a row from bottom left to top right and all will move in almost the same line as ecliptic throughout the month. I don’t remember the last time we had this kind of planetary panorama in the sky.
To make it completely obvious, a waning moon will pass below (south) Saturn on June 18, Jupiter and Mars on June 21 and 22 respectively and just north (above) Venus and Mercury on June 26. and June 27 respectively. It will be a difficult act to follow, no doubt, unless another comet passes or Betelgeuse becomes a supernova or similar.
For those who aren’t particularly excited to get up in the dark of the thirties to watch the planets rise, there are more and more things to see in our clear skies in the evening. As the solstice approaches, a couple of important stars appear in the SSE. At 10.30pm on June 1, the Big Dipper will be high to the west with the star at the end of the handle, Alkaid, almost exactly straight above. Starting at the connection to the bowl, follow the arc of the handle stars through Alkaid about twice the length of the handle to another bright star in the south, Arcturus. Remember “arc to Arcturus”. It is the brightest star in Bootes, about 37 light-years away and 10% more massive than our sun. However, it is estimated to be between 5 and 7 billion years old and has expanded to become a red giant about 25 times the diameter of the sun. If the helium in its core has not yet ignited (the helium flash) to fuse into carbon, etc., it is very close. It is a preview of what our sun will be like in 2 or 3 billion years.
From Arcturus, continue on the same arc to the next bright star, Spica, the brightest star of Virgo. Remember “speed up Spica”. Spica is about 250 light-years away and quite different from Arcturus. To begin with, it is a binary system made up of two hot young type B stars of about 11 and 7 solar masses, respectively. They are so close to each other, their orbital period is about four days and the stars are egg-shaped. Since the primary appears to be large enough to emerge as a supernova in about a few million years, this system will probably be a very interesting place to see. From a safe distance, that is, perhaps 250 light-years are more or less correct.
From Arcturus, some of our best summer views at a glance can be found easily and more with binoculars. Spica is home to many, many objects in the deep sky, some of which are also good for binoculars. These will be the starting points for next month’s celestial travel diary.
For information on the upcoming Astronomy Club meeting – Zoom or in person – on June 10, check out the club’s website at: Charles Ennis will be the speaker on the World Asterisms Project.