Lunar Eclipse on Sunday

[update: changed the time of mid-eclipse to 2:47 UT from 2:48 UT. thanks to Joe Stieber for catching the error. the one minute difference doesn’t change the rest of the article.]

Sunday evening will see the last of the recent tetrad of lunar eclipses for observers in the Americas. The eclipse will occur in the morning for observers in Europe, Africa, and western Asia. This eclipse has been hyped a bit more than usual due to the Moon being a ‘Super Moon’. What that means is the Moon is at the close part of its orbit to Earth and appears a little bit larger than usual. Regardless, all total lunar eclipses are worth seeing and this one will be very nice for western US observers as it will be located low on the horizons making for some nice views. Occurring during the early evening also means we don’t have to be up at weird hours of the night to see this one. This is especially convenient for showing the kids.

The Moon will enter the penumbra of Earth’s shadow at 00:12 UT though most observers will have a difficult time noticing any darkening of the Moon until around ~00:40 UT (8:40 pm EDT, 7:40 pm CDT). At that time the Moon will be below the horizon for Tucson and most observers in the Mountain and Pacific time zones.  The Moon enters the umbra of Earth’s shadow and really starts to get dark at 1:07 UT (9:07 pm EDT, 8:07 pm MDT, 7:07 pm MDT). At Tucson the Moon rises at 1:09 UT (6:09 pm PDT) only 1 minute after the start of the partial eclipse and 7 minutes before sunset. As the Moon gets higher and the sky gets darker it will become easier to see even as Earth’s shadow takes a bigger and bigger bit out of it.

The total phase of the eclipse begins at 2:11 UT (10:11 pm EDT, 9:11 pm CDT, 8:11 pm MDT, 7:11 pm PDT). The middle of the eclipse and the time when the Moon should appear darkest occurs at 2:47 UT (10:47 pm EDT, 9:47 pm CDT, 8:47 pm MDT, 7:47 pm PDT. Totality ends at 3:23 UT (11:23 pm EDT, 10:23 pm CDT, 9:23 pm MDT, 8:23 pm PDT) and the whole show should be over (meaning no obvious darkening of the Moon visible by ~5:20 UT.

Here in Tucson, the Moon will appear to rise at due east and will be observable in the southeastern sky for the entire eclipse.


View of the eastern horizon at the time of mid-eclipse for Tucson, Arizona. Chart created with Stellarium.

If you have a pair of binoculars or are taking images of the eclipse, note that two other relatively bright solar system objects are near the Moon. The planet Uranus is located ~15° to the due east or lower left of the Moon. At that time Uranus will be magnitude 5.7 (barely visible to naked eye observers from dark sites) and located 19.98 AU from the Sun and 19.02 AU from Earth (that’s 1.86 million miles from the Sun and 1.77 million miles from Earth). The Moon will be 0.0024 AU from the Earth (222,000 miles from the center of the Earth) or ~7900 times closer than Uranus. To the southeast of the Moon and about 11° away is the brightest asteroid, (4) Vesta. It will be 2.42 AU (225 million miles) from the Sun and 1.43 AU (133 million miles) from Earth or ~600 times further away than the Moon. Vesta will be a little fainter than Uranus at magnitude 6.2. Use the star chart below to find Uranus and Vesta.


Location of Uranus and asteroid Vesta relative to the eclipse Moon on Sunday evening Sep. 27. Chart created with Stellarium.

The next lunar eclipse will be on 2016 March 23 but will be a rather poor penumbral eclipse (meaning the darkest part of the shadow doesn’t cross the Moon). The next series of total lunar eclipses occur on 2018 January 31, 2018 July 27, and 2019 January 19. The first and third of this triad are visible in the US. Go to the NASA Lunar Eclipse page for more detail on these and other lunar eclipse.

Mid September Meteors

Finally, for the first time since the peak night of the Perseids we got a few clear nights in Tucson. The nights of Sep 16/17 and 17/18 saw 44 and 37 meteors being detected by the SALSA3 camera system, respectively. Most of the meteors are sporadics meaning they are not affiliated with any known shower. The Orionids (ORI) which will be a major producer of meteors for a few days around its Oct 21 peak were producing a few meteors per night. Other minor showers such as the September Perseids (SPE), September Lyncids (SLY) and Delta Aurigids (DAU) were occasional meteor producers.

A new meteor shower was reported by Petr Jenniskens in the Central Bureau Electronic Telegrams. The Chi Cygnids (CCY) was seen in video data from Europe and California on the nights of Sep 14 and 15 UT. A quick look through my data did not turn up any CCY candidates.

Obs Date(UT)     Time    TOT SPO ANT ORI SPE SLY DAU Oth
SAL 2015-09-20  08h 55m   28  19  3   1   -   1   1   3
SAL 2015-09-19  06h 48m   17  14  0   1   -   0   1   1
SAL 2015-09-18  09h 31m   37  26  4   2   -   1   3   1
SAL 2015-09-17  10h 30m   44  36  4   2   1   0   -   2
SAL 2015-09-16  04h 29m   9   4   2   1   1   0   -   1
SAL 2015-09-15  08h 54m   16  8   2   1   0   3   -   2
SAL 2015-09-14  03h 50m   21  13  1   5   1   0   -   1
SAL 2015-09-13  05h 05m   27  17  4   1   2   2   -   1

SAL - SALSA3 camera in Tucson (Carl Hergenrother)
VIS - Visual observations from Tucson (Carl Hergenrother)
Time - Total amount of time each camera looked for meteors 
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions
ORI - Orionids
SPE - September Perseids
SLY - September Lyncids
DAU - Delta Aurigids
Oth - other minor showers

Morning Sky Planets

Anyone up before dawn has probably noticed Venus shining like a brilliant beacon high in the eastern sky. For most of 2015, Venus was a bright object in the evening western sky. Last month it caught up with and passed the Earth moving roughly between the Earth and Sun. Over the past few weeks, it has moved out ahead of Earth which made it appear to rapidly climb higher and higher in the eastern morning sky.

Though not as bright as Venus, both Jupiter and Mars are also visible to the lower left of Venus. Over the next few weeks, all three planets will come into conjunction with each other [Oct 17 – Mars + Jupiter, Oct 26 – Venus + Jupiter, Nov 3 – Venus + Mars].


Early September Meteors

It’s been hard to get a good idea of nightly meteor rates recently. There hasn’t been a single night over the past ~2 weeks that wasn’t affected in some way by clouds. One night (Sep 4/5) was completely clouded out and another (Aug 31/Sep 1) saw a single meteor being detected between the clouds. Unfortunately I had a camera problem on the night of Sep 9/10 that saw no data collected. Not sure what happened but at some point (presumably) early in the night, the power strip that the camera and controlling computer are plugged into was switched off. My guess is our cat knocked into it.

We are currently between major showers. The Perseids of August are long over and the Orionids of October are slowly building. Even though the peak of the Orionids are over a month away, it is one of the most active showers out there right now. The September Perseids (no relations to the Perseids of August) also produced a small number of meteors during the nights of Sep 6/7/8/9. Most years this shower is a minor producer of meteors but experienced outbursts in 2008 and 2013. The 2008 outburst was detected by an earlier incarnation of my SALSA meteor video system and was the subject of the very first Transient Sky post.

Obs Date(UT)     Time    TOT SPO ANT ORI SDA AUR SPE SLY Oth
SAL 2015-09-12  09h 11m   17  11  1   4   -   -   0   1   0
SAL 2015-09-11  03h 50m   9   8   0   1   0   0   0   0   0
SAL 2015-09-10  00h 00m          --- Camera Off ---
SAL 2015-09-09  03h 59m   16  11  1   1   0   0   2   1   0
SAL 2015-09-08  04h 14m   6   4   0   1   0   0   1   0   0
SAL 2015-09-07  08h 42m   19  15  2   0   0   0   2   0   0
SAL 2015-09-06  08h 49m   23  15  3   3   0   1   0   1   0
SAL 2015-09-05  00h 00m            --- Clouds ---
SAL 2015-09-04  06h 59m   13  12  0   1   0   0   -   -   0
SAL 2015-09-03  04h 38m   8   8   0   0   0   0   -   -   0
SAL 2015-09-02  02h 25m   3   2   1   0   0   0   -   -   0
SAL 2015-09-01  00h 18m   1   1   0   0   0   0   -   -   0
SAL 2015-08-31  03h 36m   6   4   1   0   0   1   -   -   0

SAL - SALSA3 camera in Tucson (Carl Hergenrother)
VIS - Visual observations from Tucson (Carl Hergenrother)
Time - Total amount of time each camera looked for meteors 
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions
ORI - Orionids
SDA - Southern Delta Aquariids
AUR - Aurigids
SPE - September Perseids
SLY - September Lyncids
Oth - other minor showers