Latest Comic : Friday, August 10. 2018

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Mars at Closest Approach in 2018

Mars as seen in 10-minute intervals starting from the midnight of August 1, 2018

Mars comes close to Earth every two years or so, but due to the elliptical orbit the closeness varies a lot. It came as close as 0.373 AU in 2003, while it was 0.674 AU away at its approach in 2012. The closest approaches happen every 15 or 17 years, and the latest one happened on 16:50 KST, July 31, 2018, at a distance of 0.385 AU. The next one will happen in 2035. Since this year's occurrence happened during the day, I did the next best thing and got my telescope set up that night to take a good look.

Unfortunately, Mars is experiencing a planet-level dust storm since early June and it has not subsided yet. A peek at the planet during last week's lunar eclipse indeed showed a mostly uniform orange disk, confirming my fears. I wasn't about to give up, so I got my Baader filter out and hoped for the best. Thankfully, the two-hour shooting session did not go to waste as the hours of post-processing finally revealed some discernible surface details, as you can see here.


You can even observe the planet visibly rotating in this video that incorporates all the photos I took. It's similar to what I made two years ago, but the continuous shooting made for a more fluid animation.

Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 100 - 1/100s - (f/10)
Filters: Baader Moon & Skyglow
Time: 2018-07-31 23:59 - 2018-08-01 01:50 KST
Location: Naju, Korea
481 photos processed with PIPP 2.5.9 and RegiStax 6.1.0.8

Century's longest total lunar eclipse and Mars

36-photo composite of the July 2018 total lunar eclipse and the trailing Mars (click for higher resolution)

Those living in Korea was able to see the second total lunar eclipse of the year, following the one in January 31. I had multiple reasons to watch this eclipse. There wasn’t going to be another total lunar eclipse visible in Korea for nearly three years (next one is on May 26, 2021). Also, Mars was just past the opposition, shining bright next to the Moon and forming an interesting celestial pair. Finally, the eclipse was billed as the longest in the century, including more than 103 minutes of totality.

Weather cooperated well, and I was able to both observe and record the progress without a hitch. The result is the composite photo above. It was the first time my newly acquired Sony SEL55210 lens was put to use for astrophotography and it performed adequately.

Celine witnesses her first lunar eclipse after waking up early

One minor disappointment was that the Moon was to set below the horizon during the middle of the totality. So I focused on watching it comfortably in the house with my daughter instead of trying to see through every moment. In fact, it was first such eclipse visible through the southerly window since 2011, enabling Celine to see the phenomenon for the first time. She was impressed with how the full Moon progressively got dimmer from the left corner, eventually becoming red from the Earth’s shadow. Next time, I hope I can show her the comeback part.

Device: Sony A5000 + SEL55210 (E 55–210 mm F4.5–6.3 OSS)
Settings: 55mm - ISO 100 - 1/500s to 5s - f/4.5
Filters: None
Time: 2018-07-28 01:12-04:40 KST
Location: Naju, Korea

On the road with Bolt EV, part 2

The trunk was packed again to make the return trip to Naju from Ulsan

After arriving in Ulsan and charging the Bolt EV's battery as seen in the last post, my four-member family went about our own business for a couple of days. When it was time to return home, we dropped by a nearby Costco to pack up some items in the trunk. While the space was smaller compared to the one in the cars I used to drive, we were able to fit everything in.

We spent 18% of the battery charge during our stay, leaving 76%. It seemed a bit risky to attempt a full return without a mid-trip recharge since the previous trip used 73% of the battery. Still, I thought it presented an interesting opportunity to see the car's limits and pressed on casually, with the air conditioning on. The following time-lapse video shows what happened in its entirety.


As you can see, the Bolt EV was able to return to the charging station in the parking lot at home just barely. Like the previous trip, this sort of drain-to-the-bottom run should be attempted only if you're sure of the range and the charger is ready at the end. So what was the scariest moment?
Continue reading "On the road with Bolt EV, part 2"

On the road with Bolt EV, part 1

iPhone 5S set up for time lapse recording on the Bolt EV driver seat's headrest

It’s been more than a month since I started driving Bolt EV. The lack of any engine noise, as well as the responsive acceleration and regenerative breaking continue to impress even now. I felt that the car definitely belonged to the 21st century and was glad that this was the first car I bought. Driving experience aside, many still wonder and ask if the car is truly good enough for a long drive and whether the charging speed was any good. This is where showing the experience would be better than explaining.

Here is the video of my recent cross-country round trip with Bolt EV in time lapse mode using the setup you see in the photo above. It should be noted that the Korean Peninsula is only about 300km wide and the South Korean part is about 400km long. Therefore the “cross-country” isn’t on a such grand scale here. Still, the range of Bolt EV (383km) implies that it could go almost anywhere in the country with a single full charge and this is important for many potential buyers in Korea.


On the video, Bolt EV took on the task of taking my family on a routine trip to my parents’ home at the opposite coast. This trip from Naju to Ulsan covered a distance of 302.8km, of which more than three quarters were on the expressway. The day was warm and humid (more than 25C on average, with a bit of rain) and so the air conditioning was running, yet the car nevertheless passed with flying colours with plenty of margins to spare. We started out with 91% charge, and still had 18% left after reaching the destination. Let's see this in more detail.
Continue reading "On the road with Bolt EV, part 1"

FLIR ONE Pro - Inside Uses

Oven-baked spaghetti looks innocuous at a casual glance

Indoor uses of thermographic imaging camera include finding leaks of heat or water, owing to the fact that people doing repairs may have the budget and the repeated usage that justify owning such a device. But as the cost to buy one goes down and the size becomes small enough to carry in a pocket, more uses come up. The one I found useful in raising kids is cooking and food safety. As you can see here, a bowl of spaghetti straight out of an oven didn't look particularly dangerous at first...

But the bowl is quite hot at over 85C, enough to cause a burn

But with FLIR ONE Pro, you could see that the handle was quite hot. The spaghetti itself was also sizzling at over 70C. This image served as a good way to teach my kids why they should be careful with a bowl that came out of an oven.
Continue reading "FLIR ONE Pro - Inside Uses"

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