Expanding Plume from DARTs Impact

What happens if you crash a spaceship into an asteroid? In the case of NASA's DART spaceship and the small asteroid Dimorphos, as happened last week, you get quite a plume. The goal of the planned impact was planetary protection -- to show that the path of an asteroid can be slightly altered, so that, if done right, a big space rock will miss the Earth. The high brightness of the plume, though, was unexpected by many, and what it means remains a topic of research. One possibility is that 170-meter wide Dimorphos is primarily a rubble pile asteroid and the collision dispersed some of the rubble in the pile. The featured time-lapse video covers about 20 minutes and was taken from the Les Makes Observatory on France's Reunion Island, off the southeast coast of southern Africa. One of many Earth-based observatories following the impact, the initial dot is primarily Dimorphos's larger companion: asteroid Didymos. Most recently, images show that the Didymos - Dimorphos system has developed comet-like tails.

from NASA https://apod.nasa.gov/apod/ap221005.html

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The Galactic Center in Radio from MeerKAT

What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio , the galactic center can be imaged and shows itself to be quite an interesting and active place . The featured picture shows the latest image of our Milky Way's center by the MeerKAT array of 64 radio dishes in South Africa . Spanning four times the angular size of the Moon (2 degrees ), the image is impressively vast, deep, and detailed. Many known sources are shown in clear detail, including many with a prefix of Sgr, since the galactic center is in the direction of the constellation Sagittarius . In our Galaxy's Center lies Sgr A , found here in the image center, which houses the Milky Way's central supermassive black hole. Other sources in the image are not as well understood, including the Arc , just to the left of Sgr A , and numerous filamentary threads....

Peculiar Galaxies of Arp 273

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The Observable Universe

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe . In light, the farthest we can see comes from the cosmic microwave background , a time 13.8 billion years ago when the universe was opaque like thick fog. Some neutrinos and gravitational waves that surround us come from even farther out, but humanity does not yet have the technology to detect them. The featured image illustrates the observable universe on an increasingly compact scale , with the Earth and Sun at the center surrounded by our Solar System , nearby stars , nearby galaxies , distant galaxies , filaments of early matter , and the cosmic microwave background . Cosmologists typically assume that our observable universe is just the nearby part of a greater entity known as "the universe" where the same physics applies. However, there are several lines of popular but spe...

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