a cautionary autobiography
I glanced out a window last night and saw this brilliant spectacle unfurl as the second stage of a Falcon 9 traversed the sky west of Phoenix at an altitude of 90 miles and ground speed reaching more than 10,000mph:
Since this was shortly after sunset, the exhaust plume was high enough to be illuminated by the sun from over the horizon. (Here’s SpaceX’s video and mission summary.)
Now in the first week of February 2025, Venus is approaching its peak brightness. Here is a picture of it near the waxing crescent moon while at a brightness magnitude of -4.8.
This makes it 23 times as bright as Mars, which had a magnitude of -1.4 in the photos following its lunar eclipse three weeks ago:
Venus has almost twice the diameter of Mars (which itself has twice the diameter of the moon), and presently it is also only 75% as far from Earth as is Mars.
Last night (13 January 2025), North American observers could see the nearly full Moon pass in front of Mars, hiding it for as long as an hour. I got some photos of Mars emerging on the other side:
As noted last week, right now Mars is relatively close to Earth and in nearly full phase, just like the Moon in these pictures, so we are seeing the entire “day” side of Mars. Mars is twice the diameter of the Moon, but presently it is more than 200 times as far from Earth.
Coming into 2025, have you noticed that Venus and Mars are growing quite bright? Looking at a map of planetary positions it’s easy to see why Mars is approaching a point of peak apparent brightness (which it will reach on January 16): it’s on the same side of the sun as we are, so it’s relatively close; and we are aligned to see the full reflection of the sun-lit “day” side.
With Venus it’s not as easy to figure out when its apparent brightness will be maximized. When Venus is closest to Earth we are looking at its night side, so there’s no reflected light to see. When we can see the full day side of Venus it’s at its furthest from Earth on the other side of the sun, so it’s reflecting the maximum amount of light in our direction, but being so much further away the amount of light that reaches us is lower. In fact Venus goes through “phases” just like our moon does based on its position relative to the Earth and Sun, as shown in this diagram:
Next is another diagram that shows two significant points in the relative orbit of Venus: “Greatest Elongation” is when (from our perspective) the angular distance between Venus and the sun is largest. It turns out that the peak apparent brightness for Venus occurs when it is just inside its points of greatest elongation, with slightly less than half of its day side facing Earth.
Venus is at greatest eastern elongation on January 10, which puts it at its highest point in the evening sky. Its brightness will peak on February 14, at which point it will be more than 20 times brighter than the brightest star we can see (Sirius). This is so bright that it can be seen during broad daylight, if you know where to look.
I went through my landscape photos and picked the best hundred, then spent time enhancing each one to make a good background image at 4k resolution (3840×2160 pixels). I have shared them through this Google Photos album under the CC BY-NC-SA license so you can save your favorites. If you simply save the images to an album in your own Google Photos then you can set that as your “Screensaver” for any Google-connected TV or device. Enjoy!
In Phoenix we got a decent occlusion of the sun at the peak of the October 14 eclipse. Here are photos I took through an infrared filter.
I happened to be in Salt Lake City during the equinox, where I learned that Utah has outlawed a lot of things. One random example: Happy Hour. Probably Utah also prohibits human sacrifices during equinox celebrations – I didn’t even bother to ask.
So aside from weird rules what else is there in Salt Lake City? Mountains. As my many readers know, I love to photograph interesting celestial events. So I went for a hike to get this equinox sunset:
These foothills can be deceptive. I parked at one between the Big and Little Cottonwood Canyons and began to climb straight towards a peak. The first few hundred feet was fine gravel, so I had to kind of scamper from weed to weed to avoid sinking and sliding back. Then I reached sturdier ground which supports thickets of shrub-like oak trees. Those obstruct the view of what’s above, so I couldn’t be certain whether I had a good path ahead. I did eventually run into a trail bearing human footprints (though I saw no one else the entire hike). The trail wound back and forth between rocks and trees, and it was still very strenuous: When I got back I checked a topographic map and found that the straight-line route I followed from 5500 to 7500 feet averaged a 45 degree slope!
I set up my old Sony A77II with an intervalometer for an hour and managed to capture these Perseid meteors. I was using my widest lens, 16mm, shooting ISO 1600 with 10 second exposures. It took some real work to post-process and compose this image: I had to find the frames with meteors and stack and align them in Photoshop. The result is nothing great for several reasons, including that (a) meteor shower photos should use a wider lens, and (b) should include a horizon or some ground feature for perspective.
It’s easier to get better results using a smartphone, not only because a typical smartphone has a very wide lens, but also because software can take care of identifying frames that contain meteors and aligning them. After the fact I checked the app store and found at least one cheap app that does this with a built-in “Meteor Mode.”
May 15, 2022
