Tiens @jaztrophysicist t'avais vu ciel et espace ?
(oui je sais j'arrive après la bataille, c'est juste que je lis sur du papier ce que tu racontes par ici -c'était à la bibli j'ai pas eu le temps de lire en entier, mais c'est assez fouillé — comme toujours dans ce magazine)
Stars removed for effect, perhaps showing the view from outside of our galaxy. 2.5 million light years away, M31 will collide and merge with the Milky Way in about 4.5 billion years.
William Optics 61mm Zenithstar OTA, ZWO183MC camera, Celestron CGEM mount. About 40x4min exposures.
#LookUp, my good people! The peak of the #Geminids meteor shower is tonight & tomorrow!
The Geminids are thought to originate from asteroid Phaethon: a weird beast that emits dust a bit like a comet. These dust bunnies then becomes the meteor shower.
JAXA's DESTINY+ mission is scheduled to launch in 2025 and fly past Phaethon to check it out at close quarters, and find out a bit more about its composition. It's possible dust from such "active asteroids" could have delivered organics to Earth.
What #astronomers learned from a near-Earth asteroid they never saw coming
No one spotted space rock 2023 NT1 until two days after it missed us.
By Briley Lewis | Published Nov 1, 2023
"In the summer, astronomers spotted an airplane-sized asteroid—large enough to potentially destroy a city—on an almost-collision course with Earth. But no one saw the space rock until two days after it had zoomed past our planet.
"This asteroid, named 2023 NT1, passed by us at only one-fourth of the distance from Earth to the moon. That’s far too close for comfort. Astronomers weren’t going to let this incident go without a post-mortem. They’ve recently dissected what went wrong and how we can better prepare to defend our planet from future impacts, in a new paper recently posted to the preprint server arXiv.
"We know from history that asteroids can cause world-shattering events and extinctions—just look at what happened to the dinosaurs. The study team estimated that, if NT1 hit Earth, it could have the energy of anywhere from 4 to 80 intercontinental ballistic missiles. '2023 NT1 would have been much worse than the Chelyabinsk airburst,' says University of California, Santa Barbara astronomer Philip Lubin, a co-author on the new work, referring to the meteor that exploded over a Russian city in 2013. As devastating as that would be, it’s 'not an existential threat like the 10-kilometer hit that killed our previous tenants,' he adds.
"The asteroid-monitoring system ATLAS, the 'Asteroid Terrestrial-impact Last Alert System”—four telescopes in Hawaii, Chile, and South Africa—discovered NT1 after the rock flew by. ATLAS’s entire purpose is to scour the skies for space rocks that might threaten Earth. So with this set of eyes on the sky, how did we miss it?
"It turns out that Earth has what Brin Bailey, UC Santa Barbara astronomer and lead author on the paper, calls a “blindspot.” Any asteroid coming from the direction of the sun gets lost in the glare of our nearest star.” There’s another way for asteroids to sneak up on us, too: the smaller the asteroid, the harder it is for our telescopes to spot them, even when the rocks come from parts in the sky away from the sun.
“'Currently, there is no planetary defense system which can mitigate short-warning threats,' Bailey says. 'While NT1 has no chance of intercepting Earth in the future, it serves as a reminder that we do not have complete situational awareness of all potential threats in the solar system,” they add. That leads to Lesson #1: We simply need better detection methods for planetary defense."
Even those with #wings on their feet need to pause now and then, 'till the wind picks them up again.
Me? I #walktober'd over to a #photo club tonight, and met some interesting folk, heard their thoughts on #photography 😀