We recently had a blue supermoon (on 31 August 2023). If you saw it, did you think it was super? Me neither. In my previous post, I wrote about blue moons—what they are, why they happen—and in this post I aim to do the same for supermoons. Supermoons happen when a full moon occurs at a … Continue reading Blue Supermoon: Part 2
Tag Archives: Astronomy
Blue Supermoon: Part 1
On 31 August 2023 we’re going to have a blue supermoon, which will be neither particularly blue, nor particularly super, though to read some of the media coverage of these events, you might expect to see something like the image above. So I thought I might write a bit about blue moons (this post) and … Continue reading Blue Supermoon: Part 1
The Solar System’s Place In The Milky Way: Part 1
When I wrote recently about the pole stars of other planets, I was aware of one thing my sky maps didn’t show—the rotation poles of our galaxy. They weren’t really relevant to that discussion, but I’m now prompted to write a bit about the Milky Way galaxy, and our relationship to it, because I’ve just … Continue reading The Solar System’s Place In The Milky Way: Part 1
The Advent Of Atomic Time
This is, to a large extent, a companion piece to my post about leap seconds, in which I described how the irregular rotation of the Earth means that the time as measured by our atomic clocks would fall out of synchrony with the actual movement of the sun in the sky, were it not for … Continue reading The Advent Of Atomic Time
Pole Stars Of Other Planets?
When I wrote about Philip Latham’s juvenile science-fiction novel Missing Men Of Saturn (1953) recently, I pointed out that Latham had made an astronomically well-informed guess about a possible pole star for Saturn’s moon Titan. Latham (a professional astronomer) knew the orientation of Saturn’s rotation axis, which would have allowed him to deduce the location … Continue reading Pole Stars Of Other Planets?
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Which Way Does Space Station V Rotate?
The “Phenomena” posts have been a little tied up with abstruse orbital mechanics and obscure revisions to lists of Scottish hills, of late, so I thought it might be time for a break from all that. So this post is about something superficially trivial in the film 2001: A Space Odyssey, which has mildly annoyed … Continue reading Which Way Does Space Station V Rotate?
Keplerian Orbital Elements
1. All planets move in elliptical orbits, with the sun at one focus.2. A line that connects a planet to the sun sweeps out equal areas in equal times.3. The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit. Kepler’s Laws of Planetary Motion (formulated … Continue reading Keplerian Orbital Elements
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Same Sun, Other Skies
A section of the horizon was etched sharply against a pearly region of the sky. Every pointed irregularity of that part of the horizon was in keen focus. Above it, the sky was in a soft glow (fading with height) a third of the way to the zenith. The glow consisted of bright, curving streamers … Continue reading Same Sun, Other Skies
Why Does The Illuminated Side Of The Moon Sometimes Not Point At The Sun?
I took the above panoramic view, spanning something like 120 degrees, in a local park towards the end of last year. The sun was almost on the horizon to the southwest, at right of frame. The moon was well risen in the southeast, framed by the little red box in the image above. After taking … Continue reading Why Does The Illuminated Side Of The Moon Sometimes Not Point At The Sun?
We Are Stardust (Supplement)
I published my original “We Are Stardust” post some time ago, introducing the infographic above, which shows the cosmic origins of the chemical elements that make up our bodies, according to mass. At that time I concluded that Joni Mitchell should actually have sung “We are 90% stardust,” because that’s the proportion of our body … Continue reading We Are Stardust (Supplement)