BAN #169: Venus and Jupiter make a pretty pair, Kill your Facebook account

25 November 2019   Issue #169

[Saturn image credit: NASA / JPL / Space Science Institute / Gordan Ugarkovic]


Subscribers are the fifth brightest natural objects in the sky.


Pic o’ the Letter

A cool or lovely or mind-bending astronomical image/video with a short description so you can grok it

Did you see the Venus/Jupiter conjunction the other day? They passed about a degree apart in the sky, low to the west after sunset. It was a remarkable sight; the third and fourth brightest natural objects in the sky (after the Sun and Moon; the International Space Station gets about as bright as Venus but isn’t natural) so close together, especially at dusk.

I wanted to get some photos, so I found a nice little pond (northern Colorado has a bazillion of them) and set up. It was cold, but not frigid, and I wasn’t too uncomfortable. So I think it was worth it to get this shot:

[Venus (lower) and Jupiter (higher) against the twilight above the Rocky Mountain Foothills in Colorado. Click here for a full-size version. Credit: Phil Plait]

I have to say, I’m pleased with how it turned out! And this is right off the camera, with no adjustments made at all after the fact. I took this around 5:30 on Saturday, 23 November 2019. It’s a 5-second exposure at f/4, at a telephoto length of 95mm with a Nikon P900. I took about 70 shots in total, but this was the best.

I was delighted to catch their reflections in the water, too! But why do they look like lines?

If the water were perfectly still, it would act like a mirror, reflecting the sky such that the planets would look like dots. The angle of incidence equals the angle of reflection, and all that. I’d have seen the reflection of each planet directly below it in the water, on a line between my camera and the planet, such that the angle the light hits the water is equal to the angle of it bouncing upward toward my camera.

However, ripples in the water change that. Each ripple acts like its own little mirror. So in a patch of water farther away, a ripple can pop up can a part of it is at the right angle to reflect the planet-light to me. And that’s true for a patch even farther away, as well as a patch closer… as long as they are in a line along the water directly below the planet. That stretches the reflection out into those lines.

The reflections also are broadened in width a little bit because each ripple is like a little hill of water, curved, such that even if it wasn’t directly under the planet, it could still catch a bit of light and send it my way (like a mirror at an angle off to the side a little can reflect light toward you). That has a narrow tolerance, though, so you don’t see the line super broadened.

If you missed it, don’t sweat: There are more fun planetary conjunctions coming up. I mentioned a few on Twitter.

[Click that to see the thread.]

If you can, always take the opportunity to look up! There’s a lot of stuff going on in the sky over your head, and a lot of it is really pretty.



Personal Stuff

Yeah, but not too personal

One year ago today I deleted my Facebook accounts.

I have zero regrets about it. None. Despite the fact that over that time I’ve no doubt lost traffic because of this decision, since losing that avenue to my audience means less traffic to my blog posts, fewer people I can reach. But sometimes doing the right thing means taking a personal hit.

Over the past twelve months there has not been a single bit of news that makes me second guess my decision, and in fact everything — everything — that comes out about Zuckerberg and Facebook reinforces my trust that I made the right decision. The corruption and bad faith running through FB is almost cartoonish.

If I had even a whiff of regret, then maaaaaybe it would be that I could’ve deleted it all even earlier. But even then IMHO I’ve made up for that by being loud and clear to urge others to delete their accounts as well.

I know I can’t make a very big dent in that Goliath’s business, but I’m reminded of a scene from M*A*S*H. B.J. has been helping a local family in Korea, devastated by the war, and spending a lot of time and effort to do so. After some time, Hawkeye, exasperated with the devotion B.J. put into, says to him, “You can’t change the whole world!”

B.J. smiles a little, and states matter-of-factly, “Nope. Jut my little piece of it.”

That really stuck with me, and I find it to be a very motivating bit of philosophy. I have a bigger soapbox than some, smaller than others’, but whatever size my piece of the world is that I can change, change it I will.

So: If you can, delete your Facebook account. I understand if you can’t — your job, your social life, whatever, may depend on it — but if you can, then give it a try. Here’s how to do it.


Blog Jam

What I’ve recently written on the blog, ICYMI

[The Pleiades, from Friday’s post. Credit: Adam Block /Steward Observatory/University of Arizona]

Monday 17 November, 2019: The Sunburst Arc: A quirk of gravity reveals how the infant Universe lit up

Tuesday 18 November, 2019: New observations hint that Jupiter’s moon Europa erupts with water geysers (corrected)

Wednesday 19 November, 2019 :Whack 'em or nuke 'em: How to deflect a killer asteroid

Thursday 20 November, 2019: Two gamma-ray bursts emit highest energy photons ever seen from GRBs

Friday 21 November, 2019: The Pleiades like you’ve never seen them before


Et alia

You can email me at thebadastronomer@gmail.com (though replies can take a while), and all my social media outlets are gathered together at about.me. Also, if you don’t already, please subscribe to this newsletter! And feel free to tell a friend or nine, too. Thanks!