Posts Tagged ‘supermoon’

04/26/2021 – Ephemeris – There’s a full supermoon tonight

April 26, 2021 Comments off

This is Ephemeris for Monday, April 26th. Today the Sun will be up for 14 hours and 2 minutes, setting at 8:41, and it will rise tomorrow at 6:38. The Moon, at full today, will rise at 8:19 this evening.

The full moon tonight is the full Pink Moon, and a supermoon. As down as I am about full moons due to the fact that they light up the sky and flood out the dimmer objects in the sky, I once in a while stop and view it. The time of the full moon is 11:31 tonight, so when it rises tonight we will be looking at the moon from very nearly the direction of the Sun, so there will be few shadows to be had. The crater Tycho is near the bottom or south end of the moon and has long rays of tiny ejecta craters. The full moon is the best time to see these rays, which are easily visible in binoculars, through which Tycho itself looks like a bright dot. In telescopes Tycho looks like a small bright crater with a dark ring around it. The full moon is super bright. It’s daytime over there.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


High contrast full Moow
The full Moon 7 hours before it was officially full. The contrast was greatly enhanced to bring out Tycho’s ray system. The crater Tycho is at the south part of the Moon and appears bright with a dark ring around it. Credit Bob Moler.
Tycho and Kepler
Tycho and Kepler. Artist for Tycho: Eduard Ender (1822-1883). Artist for Kepler, unknown. Source: Wikipedia

Tycho Brahe and Johannes Kepler are inexorably linked in astronomical history. Tycho was famously stingy with the results of his observations. It was only after his death that Kepler was able to have access to them. Mars was the planet that was hardest to model in both the Ptolemaic geocentric and Copernican heliocentric universes, since both assumed the planetary orbits were circular. So both resorted to epicycles in an attempt to tweak their models in an attempt to fit with observational reality.

Both Tycho and Kepler have craters named for them on the Moon. Tycho gets a splashy crater on the southern part of the Moon. Kepler, however, gets a small crater on the plains of Oceanus Procellarum west of the crater Copernicus on the left side of the Moon, as we see it

06/09/2017 – Ephemeris – Watch the mini moon rise tonight

June 9, 2017 1 comment

Ephemeris for Friday, June 9th. Today the Sun will be up for 15 hours and 29 minutes, setting at 9:26, and it will rise tomorrow at 5:57. The Moon, at full today, will rise at 9:26 this evening.

In recent years we’ve talked about the super moon, when the full Moon appears especially large because it’s at perigee, or closest to the Earth at that time. Well tonight’s full Moon will be a the opposite, a mini Moon. The Moon reached apogee, its farthest from the Earth in it’s orbit at 6:21 last night, and 15 hours later, at 9:10 this morning the Moon was full. However I bet that when the Moon rises tonight that it will appear just as big as it always does, especially if you forget that it’s supposed to be a mini moon. The Moon is in an elliptical orbit of the Earth that this month varies from 252,500 miles (406,400 km) yesterday down to 222,400 miles (357,900 km) on the 23rd. Thanks to the Sun, and especially Jupiter and Venus, those distances change a bit every month. Tonight Saturn will be seen just below the moon.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Mini Moon and Super Moon

Mini Moon and Super Moon for 2017. Created using Cartes du Ciel (Sky Charts).

10/14/2016 – Ephemeris – Super Moon Sunday and a weird comet

October 14, 2016 Comments off

Ephemeris for Friday, October 14th. The Sun will rise at 7:57. It’ll be up for 11 hours and 1 minute, setting at 6:59. The Moon, 2 days before full, will set at 7:03 tomorrow morning.

The full moon on Sunday will be the Hunter’s Moon it will also be a super moon, though not quite as super as November’s super moon. I tend to disparage the effect because of the optical illusion that makes the Moon appear larger when near the horizon than when higher up. Besides there’s nothing out there of comparable size to compare it to. Farther out in space, the comet 29P/Schwassmann-Wachmann 1, which is weird among comets in having a nearly circular orbit between Jupiter and Saturn. It can be observed over it’s entire orbit. Normally a comet out that far is pretty much inactive. However every once in a while it produces an outburst, brightening and expelling a cloud of gas and dust. This can occur up to 7 times a year.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


This month’s super Moon will appear to be 33.4 minutes of arc in diameter when it will rise Sunday night at 7:40 p.m. in the Traverse City/Interlochen area.  It will be 222,393 miles (357,906 km) away.  November’s super Moon will rise November 14 at 5:53 p.m. and appear to be 33.6 minutes of arc in diameter.  Note that half a degree is 30 minutes of arc.  Last April 2nd’s mini Moon was 29.4 seconds of arc in diameter when it rose.  It was 252,262 miles (405,977 km) away.  This full Moon will appear 13.6% larger than last April’s  full Moon.

09/22/2015 – Ephemeris – Equinox tomorrow and September 27th Moon’s triple whammy

September 22, 2015 Comments off

Ephemeris for Tuesday, September 22nd.  The Sun will rise at 7:29.  It’ll be up for 12 hours and 11 minutes, setting at 7:40.   The Moon, 1 day past first quarter, will set at 2:02 tomorrow morning.

Tomorrow at 4:20 a.m. before most of us wake up summer will officially end and Autumn will start.  That’s the exact time of the autumnal equinox.  We are noticing that the days or rather daylight hours are getting noticeably shorter day by day.  Autumn will end when the days will stop getting shorter on the first day of winter, December 21st.  The full moon this Sunday is triply important.  Most important is that a total lunar eclipse will happen.  Second, it is the Harvest Moon, the nearest full moon to the autumnal equinox, more on that next week.  Also it is the closest the Moon gets to the Earth all year.  Yup it’s a so-called supermoon.  If the Moon were a 2 inch ball it would be 20 feet from an 8 inch Earth.  The supermoon is a foot closer.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


That last bit about the Moon being a two-inch ball will come in handy if you come to the Girl Scout Badge Bash at ECCO in Traverse City Thursday night.

09/08/2014 – Ephemeris – There’s a super Harvest Moon tonight!

September 8, 2014 Comments off

Ephemeris for Monday, September 8th.  The sun will rise at 7:13.  It’ll be up for 12 hours and 53 minutes, setting at 8:06.   The moon, at full today, will rise at 7:44 this evening.

Tonight’s full moon is the Harvest Moon, being the closest full moon to the autumnal equinox.  It’s about the earliest Harvest Moon on can get in the year, occurring 14 days before the equinox because the moon’s cycle is 29 ½ days, and the autumnal equinox falls on the 22nd not the 23rd as usual.  On top of that it’s another supermoon.  Perigee or the Moon’s closest approach to the Earth of the month occurred yesterday.   We were all oblivious to the fact until some astrologer wrote about it a few years ago.  It’s nice to know.   Actually there’s a supermoon every month but it only nearly coincides with the full moon one to three times a year at consecutive full moons.  Trouble is the Moon always appears bigger near the horizon.  It’s an illusion.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


See here for last month’s discussion about the supermoon.


Supermoon, Smoopermoon

August 9, 2014 2 comments

Pardon me if I don’t get excited by the fact that we are going to have a “supermoon” August 10th. On the night of the full moon it will be at perigee, its closest point to the Earth in its orbit.  The distance according to our Celestial Calendar page is 356,897 kilometers.  That’s 221,766 miles.  At apogee this month, on the 24th, the moon will be 406,523 kilometers, or 252,602 miles away.  That’s somewhat larger than 11 percent difference in distance, due to the Moon’s elliptical orbit.  The name for the smallest moon is micromoon.  Either is an exaggeration of terms.

A supoermoon compared to a micromoon.  Credit: Michael Myers.

A supoermoon compared to a micromoon. Credit: Michael Myers.

I don’t remember the supermoon term growing up.  Wikipedia says it was coined by astrologer Richard Knolle in 1979 according to his web post from 2011.  Oooo, an astrologer.
There’s a profession astronomers can respect. </snark>*

Being a relatively old guy, 1979 was well past my formative years as an amateur astronomer and even four years after I started producing my Ephemeris programs for Interlochen Public Radio.  Yet I only remember supermoon being a big deal or any deal at all for the last few years.
The actual size of the supermoon aside, folks mistake the normal optical illusion of an enlarged moon rising as the supermoon.  The moon always looks larger when it’s near the horizon than when it’s high in the sky.  The same thing happens to the sun, it looks larger rising and setting, the when higher in the sky.  Caution:  Use a solar filter to observe the sun.  In photographs the Moon is the same size whether on the horizon or high in the sky.  Actually the horizon moon will appear slightly smaller on the horizon.  One, it will be squished vertically by the action of the refraction of the earth’s atmosphere. Two, it is nearly 4,000 miles farther away at the horizon than at he zenith, where we’re the radius of the Earth closer to the Moon.

I challenge anyone to be able to actually detect, by looking at the moon in the sky, whether they are looking at a supermoon or not.  There’s nothing of comparable size out there.  The same thing will happen when one thinks the full moon is so white.  OK, there’s some gray too.  However the Moon’s total albedo of reflectance is 0.136 or 13.6%.  Some say 0.07 or 7%, comparable to a charcoal briquette.  If one could get Saturn’s moon Enceladus, with nearly a 100% albedo, next to the Moon without it turning into a comet by sublimating away, the dinginess of our Moon would be immediately obvious.

08/08/2014 – Ephemeris – Supermoon plus astronomical fun in the Grand Traverse Area

August 8, 2014 Comments off

Ephemeris for Friday, August 8th.  The sun rises at 6:36.  It’ll be up for 14 hours and 21 minutes, setting at 8:58.   The moon, 2 days before full, will set at 5:17 tomorrow morning.

In two days the Moon will reach perigee within a few hours of being a full moon.  This has become known as a supermoon.  Perigee is the point where an Earth orbiting object is closest to the Earth.  The farthest point is called apogee.  The coincidence of full moon and perigee was coined as the supermoon by astrologer Richard Knolle in 1979, but apparently didn’t catch on until he wrote a popular article in 2011.  No wonder I hadn’t heard of it, this program had been on for 4 years before the term was even coined.  The problem with appreciating the supermoon is the lack of a reference of nearly the same size.  The moon always looks large when it’s near the horizon.  It’s a well-known optical illusion,  It’ll fool us every time.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


Saturday evening the 9th the Grand Traverse Astronomical Society (GTAS) will host a Sun and Star Party at Thoreson Farm at the Sleeping Bear Dunes National Lakeshore.  It’s the concluding event at the Port Oneida Fair.  Solar viewing will be from 4 to 6 p.m., and the evening event will run from 9 to 11 p.m. with the main attraction will be the nearly full Moon, the planet Saturn and colorful binary stars and bright star clusters.  Thoreson Farm is located on South Thoreson Road.  South Thoreson Road runs into M22, about a mile west of Port Oneida Road.

Sunday evening the 10th the GTAS will attend the Meteors and S’mores event at the Leelanau State Park at the tip of the Leelanau Peninsula.  The event will run from 8:30 p.m. to 11:45 p.m.  The Perseid meteor shower will reach peak a couple of days later, but there will still bright Perseids visible to the vigilant.

I’ll have more to say about the supermoon tomorrow in a non-Ephemeris post.