Mercury Update - Details for 2018

Mercury has seven elongations in 2018. The initial sighting for each of these is tabulated below:

Sequence

Initial Sighting Date (2017/18)

Observing Location

Greatest Elongation (2018)

#1

December 24, 6:10 am EST Swede Run, Moorestown, NJ

January 1, western (morning)

#2

February 26, 5:56 pm EST Baseball Fields, Maple Shade, NJ

March 15, eastern (evening)

#3

April 22, 5:26 am EDT Old Mart Site, Pennsauken, NJ

April 29, western (morning)

#4

   

July 12, eastern (evening)

#5

   

August 26, western (morning)

#6

   

November 6, eastern (evening)

#7

    December 15, western (morning)

 

Elongation #3

The first sighting of the third elongation for 2018 was on April 22, 2018, at the old mart site in Pennsauken, NJ. Mercury, at magnitude +0.9, was initially seen with 15x56 binoculars at 5:26 am EDT, 5 minutes after it rose when it was at 1.0 altitude and 89 azimuth (and 53 minutes after the start of astronomical twilight, 46 minutes before sunrise). Its diagonal rising path was followed until 5:40 am when it reached 3.5 altitude. It was also seen with an 85 mm spotting scope at 27x, but it was not seen with unaided eyes. The sky was quite clear this morning, even along the eastern horizon (unlike the streaky horizon clouds present on the three previous failed attempts in the past week at Swede Run). The bright planets Mars, Saturn and Jupiter were obvious to unaided eyes upon arrival at 5:23 am.

 

Elongation #2

The first sighting of the second elongation for 2018 was on February 26, 2018, at the baseball field complex in Maple Shade, NJ. Mercury, at magnitude -1.4,  was initially seen with 15x56 binoculars at 5:56 pm EST, when it was at 5.4 altitude and 3.6 below Venus (at the 5 o'clock position). Mercury was followed until 6:10 pm when it descended into the tree tops at 2.2 altitude. It was never seen with unaided eyes. Venus, magnitude -3.9, was initially seen with the 15x56s at 5:52 pm, then immediately afterwards with unaided eyes. It was the first sighting of Venus with unaided eyes since its superior conjunction on January 9, and the first sighting since it was seen with binoculars on January 25.

The second sighting of the second elongation for 2018 was on February 28, at Swede Run in Moorestown, NJ. It was briefly seen in 15x56 binoculars at 5:54 pm EST, when it was 2.4 from Venus at the 5 o'clock position, in the same 4.5 binocular field. Shortly after, it disappeared into a thickening cloud bank above the western horizon.

The third sighting of the second elongation for 2018 was on March 3, at the baseball field complex in Maple Shade, NJ. It was briefly seen in 15x56 binoculars at 6:34 pm EST, when it was 1.1 to the right Venus, through a gap in the clouds just above the distant tree tops. At the time, it was mostly overcast, except for some fast-moving clear streaks in the clouds along the western horizon (it was also somewhat windy from the remains of yesterday's nor'easter). The image below was captured at 6:36 pm with a Canon 6D digital SLR camera (on a fixed tripod) and a Sigma 70 to 300 mm, f/4-5.6 zoom lens set to 300 mm focal length, then cropped to about 60% of the original size (and a 16:9 ratio), which yielded a field about 4.6 wide x 2.6 high. Venus (magnitude -3.9) is on the left, dimmed somewhat by the foreground cloud and Mercury (magnitude -1.2) is on the right. They were approximately 3 altitude in the picture. Venus was seen with unaided eyes several times as the clouds passed, but Mercury was not unambiguously seen with unaided eyes.

 

An image from March 3, 2018.

The fourth sighting of the second elongation for 2018 was on March 4, at Swede Run in Moorestown, NJ. Mercury and Venus were initially seen with 10x50 binoculars on arrival at 6:03 pm, then Venus was seen immediately with unaided eyes, but not Mercury with any certainty (1.2 separation). Upon completing camera and tripod setup at 6:15 pm, Mercury was definitely visible with unaided eyes. By 6:25 pm, they were both easily visible with unaided eyes. They were still visible as they disappeared into the distant trees around 6:40-6:45 pm. The sky was quite clear.

The fifth sighting of the second elongation for 2018 was on March 5, at the railroad tracks near Steinhauer School in Maple Shade, NJ. Mercury and Venus were initially seen with 10x50 binoculars on arrival at 5:52 pm, 4 minutes before sunset. Venus was then seen immediately with unaided eyes, but not Mercury with any certainty (1.5 separation). I then went to the baseball field complex, and after setting up the camera, Mercury was definitely visible at 6:15 pm with unaided eyes. By 6:30 pm, they were both easily visible with unaided eyes. They were still visible as they approached the distant trees around 6:40-6:45 pm.

The sixth sighting of the second elongation for 2018 was on March 9, at home in Maple Shade and at Swede Run in Moorestown, NJ. It was a very clear evening and I saw both Venus and Mercury out the rear window of my kitchen, through tree branches in the back of the yard, with unaided eyes at 6:30 pm EST. I then left for Swede Run, and as I drove along the railroad tracks in Maple Shade, I could see the pair quite brightly through my windshield as I made a short detour west, then in my exterior rear-view mirror after I turned back towards Swede Run. At Swede Run, they were prominent above the horizon when I arrived at 7:50 pm. I last saw Mercury at 7:15 pm when it was around 1 altitude. Venus was still at magnitude -3.9 while Mercury had dropped to magnitude -0.9. The reason I went to Swede Run was to spot the "Humanity Star" satellite, which I did. It was unusual in that it was mostly a dim, binocular object (appx. magnitude 6), except for irregular bright blinks (appx. magnitude 2), most unlike an Iridium flare or a tumbling satellite.

The seventh sighting of the second elongation for 2018 was on March 18, at Swede Run in Moorestown, NJ. It was a very clear evening and I saw both Venus and Mercury again after sunset (7:10 pm EDT), but they were also joined by the 1.5-day-old Crescent Moon. The picture below shows them at 8:01 pm EDT. The Moon, of course, is at the lower left, Venus is at the center and Mercury is at the upper right (Canon 6D + 200 mm f/2.8L, not cropped).

 

An image from March 18, 2018.

All three objects were easily visible above the tree tops to the west. The Moon was at 4.3 altitude and 2.5% illuminated. Venus, 3.9 from the moon, was at 5.3 altitude and magnitude -3.9. Mercury, 3.8 from Venus, was at 7.2 altitude and magnitude +0.4. After taking pictures, I looked at Mercury with an 85 mm spotting scope at 27 to 60x, hoping to see its crescent shape (at the time, Mercury was 30% illuminated). It was difficult to discern due to the small diameter (8.5") and poor seeing, but Mercury looked oval rather than round.

The eighth sighting of the second elongation for 2018 was on March 24, at Atsion Field in Wharton State Forest, NJ. There were some murky thin clouds along the western horizon and Mercury was now 7 below-right of brilliant Venus. She was first sighted at 6:45 pm EDT, 30 minutes before sunset, with 15x56 binoculars, then shortly after, with unaided eyes. Mercury was finally spotted at 7:36 pm with an 80 mm refractor at 53x (1.9 field), not far above the tree tops. Knowing the position, it was then seen with the 15x56s. It was popping in-and-out of the clouds and was never seen with unaided eyes. At the time, Mercury was 9.8" apparent diameter, 11% illuminated, magnitude +2.2 and 8.2 altitude. In the scope at 102x, Mercury looked non-circular, perhaps like a horizontal oval, although with poor seeing at that altitude, it wasn't clear-cut. It certainly didn't look like the thin crescent it was. The crescent would have appeared horizontal since Mercury was 12.8 directly above the sun at the time (the ecliptic was tilted a steep 74 to the horizon and Mercury had an ecliptic latitude of +3.4). A dramatic change from six days ago on March 18 and probably the last sighting for this fine elongation.

 

Elongation #1

The first sighting of the 2018 elongation cycle was on December 24, 2017, at Swede Run in Moorestown, NJ. It was initially seen with unaided eyes just above the tree tops at 6:00 am when it was magnitude +0.2 and 3 altitude. However, because the sky was generally cloudy with clearing mainly between streaky clouds along the eastern horizon, there were no visible reference stars to confirm the position. In particular, Antares was 8 from Mercury at the 4 o'clock position, and until I saw both objects, I couldn't be sure which was which. With 15x56 binoculars, I spotted Antares in the trees at 6:10 am, and over the next five minutes, it showed movement up and to the right, so it wasn't a distant antenna warning light (there are many antennae around Lockheed-Martin in that direction). Antares was also confirmed by spotting Aliyat (Sigma Scorpii) 2 from Antares at the 1 o'clock position.

The second sighting of the first elongation of 2018 was on December 28, 2017, at Swede Run, when the temperature hovered around 14F. It was initially seen with an unintentional glance of unaided eyes just above the tree tops at 5:55 am, when it was magnitude -0.2 and 3 altitude. A few minutes later, Antares was spotted 8.6 to the right of Mercury (at the 3:30 o'clock position), confirming the sighting. The image below, looking southeast down Westfield Rd towards the intersection of Borton Landing Rd, was captured at 6:04 am EST with a Canon 6D digital SLR camera and a Canon 100 mm f/2.8L macro lens on a fixed tripod. It was exposed 1 second at f/4, ISO 4000. It was cropped to about 75% of the original size for a field 15 wide x 10 high. Mouseover for labels. Mercury was still visible with unaided eyes when I left at 6:30 am.

An image from December 28, 2017.

The third sighting of the first elongation of 2018 was on January 1, 2018. First, I wanted to make sure I saw this 2018 elongation in 2018, not just 2017, and second, I wanted to catch Mercury on the day of its greatest western elongation, which is January 1 at 2:58 pm EST. We're still in a cold spell and the temperature hovered around 8F. Initially, I went to Swede Run in Moorestown, NJ. After picking up (4) Vesta (in Libra) with 15x56 binoculars at 5:45 am EST, I spotted Mercury in the treetops at 5:52 am with the 15x56s, then saw it with unaided eyes at 5:53 am; it was magnitude -0.3 and 2.3 altitude. After leaving Swede Run, I decided to check out the old Mart site in Pennsauken, NJ, which had been my workhorse morning twilight site until construction started there in August 2017. As soon as I pulled up, I could easily see Mercury through the windshield at 5.2 altitude. Based on what I could see in the semi-darkness of twilight (the sun wouldn't rise until 7:22 am), they were still preparing the ground at the Mart site as no visible structures had risen yet. When I arrived home at 6:25 am, Mercury was still easily visible at 7.4 altitude in brightening skies. Mercury's position viewed from home this morning was reminiscent of the first sighting in this series of observations back in January 2011.

The fourth sighting of the first elongation of 2018 was on January 14, 2018, from Swede Run during morning twilight with the temperature at 14F. I arrived at 6:15 am EST, and although the sky was generally clear, there was a band of clouds starting a few degrees above the tree line and ending below Jupiter and Mars, which were around 30 altitude. The Crescent Moon was in the band of clouds and popped in and out of view until it emerged from the cloud bank at 6:45 am. Regardless, glimpses of the moon through the clouds guided me to Mercury, which I picked up at 6:16 am with 15x56 binoculars. Saturn, a couple of degrees west of Mercury, also peeked in and out of the clouds and during the next ten minutes, I momentarily had Mercury and Saturn in the same binocular field several times. Finally, I was able to see Mercury with unaided eyes at 6:25 am, but I never caught Saturn with unaided eyes.

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The current sighting streak is now 47 elongations in a row, starting in January 2011, which includes seven complete calendar years of six or seven elongations. The years 2011 and 2015 each had seven (7) elongations, while 2012, 2013, 2014, 2016 and 2017 each had six (6). Click here for previous sightings. The purpose of this ongoing effort is not to set some sort of record, especially since I have no idea what sort of record might exist, but to demonstrate that locating and seeing Mercury is not nearly as difficult as many suppose. It just takes some planning and a little effort.

 

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Last Update: Sunday, April 22, 2018 at 03:57 PM Eastern Time