When a small galaxy strays too close to the Milky Way, the gravity from our larger galaxy reels it in. Gas and stars are ripped from the passing galaxy as it falls inward toward its doom, creating streams of material that stretch between the galactic pair. These streams continue to tear away stars until the infalling object has been completely consumed. After the merger is over, some of the only remaining signs of the devoured object are the stellar streams snaking through the Milky Way, a small sample of stars from a galaxy long gone.
In addition to being a record of the past, one of these streams may provide the first direct evidence for small scale clusters of dark matter—the elusive material that is believed to account for 85 percent of all matter in the universe. A recent analysis of a trail of stars reveals that it interacted with a dense object in the last few hundred million years. After ruling out the most likely suspects, the researchers determined that the relatively recently made gap in the stream may have been caused by a small clump of dark matter. If confirmed, the eddies of this stellar stream could help scientists sort through the competing theories about dark matter and perhaps even close in on the characteristics of the mysterious material.
8-6-2021 (August 6, 2021) is the Snakiest day of the year and it’s also this year’s CircuitPython Day! The day highlights all things CircuitPython and Python on Hardware. See you there!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.