Wesley's Tool-Box

Night sky is home to various satellites, both natural and artificial. I've taken photos of these objects in the past few days and here are a couple them for you to enjoy.

The Iridium satellites are known for their flares caused by the interesting shape of their antennae. I had a chance to observe Iridium 97 moving down the northern sky with my iPhone XS. While the satellite shined noticeably for about twenty seconds, this merging of a 1-minute, 610-photo session reveals that it was still dimly visible for some time before and after that. The rest of the satellite reflects the sunlight, just not as effectively.

Device: iPhone XS
Settings: 26mm - ISO 2500 - 1/15s - f/1.8
Filters: None
Time: 2019-02-17 19:04:46-19:05:46 KST
Location: Naju, Korea
610 photos merged with Startrails 2.3


This lunar year's first Full Moon (Jeongwol Daeboreum) was coincidentally a Super Moon. A bigger one would not appear until December 24, 2026. I took this photo just moments after the phase reached its peak, with a visible size of 34' 02.37" and a distance of 350,840km. As a result, it appears nearly 4,000 pixels wide (3,955 pixels, 0.516"/pixel). Unless I keep using the P1000 seven years later, this would be the largest photo of the Moon this camera would ever take.

Device: Nikon P1000
Settings: 3000mm - ISO 100 - 1/400s - f/8
Filters: None
Time: 2019-02-20 01:11:49, 01:14:07 KST
Location: Naju, Korea
2 photos merged with Pixelmator 3.8.1

Tiangong-1, the first Chinese space station, is set to fall back to Earth around April 2. Its orbit had been slowly decaying since its service was ended in 2016. I found out that it would be visible for one last time in the sky this morning, so me and my daughter Celine decided to witness its streak. I set up my iPhone X on a tripod and placed it on the window facing north. Then I launched NightCap Camera app in satellite capturing mode.

Shortly after 5:30AM, Tiangong-1 made its bright (-0.6 magnitude, 181km altitude) appearance from the west, streaking towards east and quickly dimming. Just as it disappeared from our eyesight, another bright flash appeared to the east of Polaris and then quickly disappeared. From my experience I knew that was an Iridium flare. CalSky website verified it to be Iridium 80, showing up at 5:30:36AM with a magnitude of -2.0. We were very lucky to see the two together - since the space station will disappear in a couple of days it was truly a once-in-a-lifetime experience.

On the photo, you can see, starting from the top left and looking towards bottom right, the Tiangong-1, Polaris, Iridium 80, and the Cassiopeia constellation. Click on the image to see it in full size.

Device: iPhone X
Settings: 28mm - ISO 2112 - 61s - f/1.8
Filters: None
Date/Time: 2018-03-31 05:30:01 KST
Location: Naju, Korea

It's been more than two years since I talked about satellite flares here, but I now have something to show you. As you can see, I had a camera successfully capture the flares coming from an Iridium satellite for the first time. Past efforts used iPhones because I was focused in capturing the motion of the flares. In this photo, the ever-growing Naju Bitgaram City provided a colourful backdrop.

Device: Sony A5000 + SELP1650 (E PZ 16–50 mm F3.5–5.6 OSS)
Settings: 24mm - ISO 400 - 20s - f/4.5
Filters: None
Time: 2016-08-30 05:06 KST
Location: Naju, Korea

Last Thursday, Iridium 12 was making a bright, magnitude -6.1 flare in the northern sky just below Polaris, so I took its photos with my iPhone. To eliminate the camera shake in the images, I used Hugin for the first time. It seems to do an excellent job of it.


Device: iPhone 5S
Settings: 30mm - ISO 2000 - 1/15s - f/2.2
Filters: None
Time: 2014-04-03 19:58 KST
Location: Suwon, Korea
240 photos stabilized with Hugin 2013.0.0 and combined with Startrails 2.3

This is a recording of the flare from Iridium 20 satellite over at Yatap subway station in Seongnam.

Device: iPhone 5S
Settings: 30mm - ISO 1250 - 1/15s - f/2.2
Filters: None
Time: 2014-01-28 19:25 KST
Location: Seongnam, Korea