Astro Blog

https://www.scientificamerican.com/article/astronomers-spot-first-ever-space-rock-from-another-star/ Source:   By Lee Billings, Scientific American Excerpt: For the first time ever, an asteroid or comet from another star has been caught hurtling through our solar system, astronomers announced late Thursday. Provisionally designated A/2017 U1, the object appears to be less than a half-kilometer in diameter and is traveling at just over 40 kilometers per second—faster than humanity’s speediest outbound space probes. Because this is the first object of its type to be found, there are as yet no official rules for naming it, and its discoverers have balked at suggesting anything besides “Interstellar.” Whatever one might call it, though, it is presently racing away from the sun and has sparked a stampede of astronomers rushing to observe it before it fades entirely from view in the darkness of interstellar space. “All we can say right now is this was something that was tossed out of ano

https://www.nytimes.com/2017/10/16/science/ligo-neutron-stars-collision.html Source:   By Dennis Overbye, The New York Times 2017-10-16. . . For GSS A Changing Cosmos chapter 9. Excerpt: Astronomers announced on Monday that they had seen and heard a pair of dead stars collide, giving them their first glimpse of the violent process by which most of the gold and silver in the universe was created. The collision, known as a kilonova, rattled the galaxy in which it happened 130 million light-years from here in the southern constellation of Hydra, and sent fireworks across the universe. On Aug. 17, the event set off sensors in space and on Earth, .... Such explosions, astronomers have long suspected, produced many of the heavier elements in the universe, including precious metals like gold, silver and uranium. ...a pair of neutron stars, the shrunken dense cores of stars that have exploded and died, collided at nearly the speed of light. These stars are masses as great as the sun packed