astronomy
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Aviation vs. Eclipse
Contrails form behind jet aircraft flying through the stratosphere. Since high-altitude aviation is happening all around the earth more or less constantly, planes are painting the sky everywhere. (Here is one time-lapse. And another. And one of my own.) Many contrails don’t last, of course, but many do, and together they account for much of… Continue reading
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Saving Mount Wilson
This was last night: And this was just before sunset tonight: From the Mt. Wilson Observatory website: Mount Wilson Observatory Status Angeles National Forest is CLOSED due to the extreme fire hazard conditions. To see how the Observatory is faring during the ongoing Bobcat fire, check our Facebook link, Twitter link, or go to the HPWREN Tower Cam and click on… Continue reading
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A rare sky treat
Across almost 73 laps around the Sun, I’ve seen six notable comets. The fifth was Hale-Bopp, which I blogged about here, along with details on the previous four, in 1997. The sixth is NEOWISE, and that’s it, above, shot with my iPhone 11. There are a couple other shots in that same album, taken with… Continue reading
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Coming From Every Here
To answer the question Where are SiriusXM radio stations broadcasted from?, I replied, If you’re wondering where they transmit from, it’s a mix. SiriusXM transmits primarily from a number of satellites placed in geostationary orbit, 35,786 kilometres or 22,236 miles above the equator. From Earth they appear to be stationary. Two of the XM satellites,… Continue reading
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The universe is a start-up
“Pillars of Creation” is a live view of stars forming in a neighboring region of the Milky Way. (Inside the Eagle Nebula, 5,400 to 6,100 light years away.) The Solar System, formed 4.6 billion years ago. Earth became a planet .46 billion years later. That was 9.247 billion years after the Big Bang, which happened 13.787 billion years ago, meaning… Continue reading
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Venus, Moon, Jupiter and Mercury in the dawn’s early light
Walked out on the front deck this morning and grabbed a photo set of the Moon between conjunctions with Venus (that was yesterday), Jupiter (tonight and tomorrow) and then Mercury (Saturday), before passing next to the Sun as a new moon on Sunday. More about the show at EarthSky. Get up early and check it… Continue reading