THE FARSIDE OF THE SUN IS ACTIVE: Multiple solar radio bursts and CMEs have emanated from the farside of the sun this week. Helioseismic maps of the sun show the reason why. There are three significant sunspot groups transiting the farside. One of them is an old friend: Sunspot 4274, which caused the Veteran's Day aurora and radiation storm. It'll be back after Thanksgiving. Solar flare alerts: SMS Text.
INTERSTELLAR COMET 3I/ATLAS IN COLOR: Who needs satellites and space agencies? Using a backyard telescope on Earth, amateur astronomers Michael Jäger and Gerald Rhemann have just captured the best-yet color image of interstellar visitor 3I/ATLAS. It is unmistakably a comet.
"We used a 12-inch telescope with a QHY600 cooled astronomy camera and color filters," says Jäger.
With one exception (discussed below), the photo is "classic comet." The comet's long tail streams straight away from the sun, sculpted by solar wind. Its blue color comes from carbon monoxide ions, CO+, a compound found in almost all Solar System comets. The comet's head is green because of another common molecule, diatomic carbon (C2), which is released from icy comet cores when they get close to the sun.
Now for the exception: There is a jet poking out of 3I/ATLAS's head toward the sun. It stands out in this black-and-white image taken by Michael Jäger and Gerald Rhemann on Nov. 20th:
This is unusual. Solar System comets rarely have such "anti-tails." This has prompted some (actually just one) astronomer to suggest that 3I/ATLAS might have an artificial thruster.
There is, however, a completely natural explanation. 3I/ATLAS spent a very long time in interstellar space. Billions of years of cosmic ray bombardment may have altered its surface--knocking hydrogen atoms out while heavier molecules remained behind. Now that 3I/ATLAS is in our solar system, sunlight is warming that crust and causing it to shed relatively large, heavy grains of dust. These grains are too massive to be quickly pushed around by radiation pressure or the solar wind. Instead they linger, creating a sunward-pointing jet that does not bend backward like a normal tail.
The backyard conclusion: 3I/ATLAS is a comet, and a wonderful one.
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THE HYDROGEN-ALPHA RING FOR MEN: The Earth to Sky Store sells a lot of gifts for women. This one is for men. It's the Hydrogen Alpha Ring, returning from a trip to the stratosphere on Nov. 16th.
You can have it for $126.95. The Hydrogen-Alpha Ring is the same color that hydrogen atoms emit in the sun's hot atmosphere: Red at a wavelength of 656 nanometers. Space-black edges of beveled tungsten carbide frame the deep-red band.
Multiple sizes were flown. If you're not sure, select size "11" during the checkout process; that fits most fingers. Your purchase comes with a greeting card showing the ring in flight, and telling the story of its journey to the edge of space.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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