Dr. John Barentine FRAS
@JohnBarentine
Astronomer. Historian. Arizona native. Proud LGBT American. 🏳️🌈 Retiring to asteroid 14505. @[email protected]
My field of study is having a moment, y'all. We made the cover of @ScienceMagazine. My inner 16-year-old, who read this same journal in his high school library three decades ago, is grinning from ear-to-ear at the moment. science.org/toc/science/38…
My dudes, it’s not *that* kind of “defense”.
NASA currently leads the nation's planetary defense efforts, but some are calling for the Space Force to take control. space.com/astronomy/aste…
Every now and then make sure to spend a night far away from big city lights.
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AST's BlueWalker-3 was launched in Sep 2022, it had been transmitting TT&C on 435.700 MHz inside the #amateurradio band as part of a constellation with plans for 243 more satellites transmitting TT&C in the 430-440 MHz amateur band. BW3 operates under network filings made on…
Today's H-alpha Sun in good seeing conditions at 16:40 UTC.
"@CurtinUni researchers have undertaken the world's biggest survey of low-frequency satellite radio emissions, finding Starlink satellites are significantly interfering with radio astronomy observations, potentially impacting discovery and research." phys.org/news/2025-07-a…
Today's H-alpha Sun in good seeing conditions at 16:50 UTC. I fiddled with the etalon today in order to get it closer to the line center, which brings out some more detail in the eastern half of the disc.
Light pollution is one of the most radicalizing phenomena to me, in how it has robbed the majority of the world's population of one of the most beautiful parts of our planet's patrimony.
"A Connecticut man claims state courts don’t comply with a state law. He is looking for answers about the light pollution he contends is emanating from court buildings in the state and has now taken his quest for dark skies to the courts." courant.com/2025/07/22/a-c…
Today's H-alpha Sun in fair seeing conditions (and through thin clouds) at 16:45 UTC.
tl;dr summary: it's the ipRGCs (intrinsically photosensitive retinal ganglion cells). "[O]ur results suggest cone photoreceptors do not play a measurable role in the effects of light on melatonin suppression and subjective alertness at night." cell.com/iscience/fullt… #Vision
.@DianeTurnshek on her longtime efforts to combat light pollution in Pittsburgh, Pennsylvania: "I would like to teach people that darkness has value. That it’s not just the absence of light." (by @caraNYT for @nytimes) nytimes.com/2025/07/22/cli…
Yes, but how many giraffes is that?
A plane-sized asteroid is expected to pass Earth next week. Here's why this encounter is more routine than remarkable, according to NASA experts. abcnews.link/B4vKJBI
#TIL I learned about 'space humanism' from @STEMartsLab.
Today's H-alpha Sun in good seeing conditions at 17:00 UTC.
"This discovery answers the longstanding mystery of the star’s varying brightness and provides insight into the physical mechanisms behind other variable red supergiants." #astronomy noirlab.edu/public/news/no…
Today's H-alpha Sun in good seeing conditions at 17:05 UTC.
