Physics Buzz

It’s the beginning of a story that draws you in, but it’s the ending that leaves you lingering, forever connected to the characters. At least if it’s a good story. The fairy tale of Rosetta and Philae , the first spacecraft and lander to rendezvous with a comet and travel with it in orbit around the sun, came to a close early Saturday morning (EDT) in a well-crafted ending.

Impression of Rosetta mission landing. Credit:  ESA/ATG medialab ; Comet image: ESA/Rosetta/Navcam History will be made when Rosetta's lander Philae makes a soft touchdown on a comet tomorrow.  ESA's Rosetta  spacecraft first captured the world's imagination back in January when it  reawakened  from hibernation, and tomorrow's landing will mark the crowning achievement in an already scientifically-rewarding mission.

A comet on express delivery from the Oort cloud of rock and ice that surrounds our Solar System makes a close approach of Mars this weekend. Martian satellites are already hunkering down against the potential onslaught of debris. Comet C/2013 A1, aka Siding Spring, shown as the reddish central object in four snapshots by NASA's  NEOWISE  mission in July 2014. Credit:  NASA/JPL On Sunday October 19th, comet C/2013 A1, familiarly known as comet Siding Spring, will fly within 87,000 miles of the Martian surface and NASA is determined not to miss the show. Check out their  slick animation  of how the close encounter will go down. The closest approach distance is tiny on astronomical scales — roughly equal to 1/3 the distance between us and the Moon.

Last September, two telescopes captured a spectacular flash of light on the moon's surface lasting more than 8 seconds — the longest and brightest flash ever confirmed on the lunar surface. Scientists have now attributed the record-breaking flash to a meteoroid impact and the resulting vaporization of plasma in a paper published online yesterday in the Monthly Notices of the Royal Astronomical Society . Despite the huge flash, the cause was relatively small — a rock about one meter across. Nonetheless, researcher Jose Madiedo (University of Seville) and his team estimate that the rock slammed into the surface at speeds exceeding 50 kilometers per second, leaving a crater roughly 45 meters wide. A picture of the lunar impact from September 11, 2013.  The flash caused by a meteoroid impact lasted for over 8 seconds — the longest flash ever confirmed. Image Credit : Jose Madiedo et. al/MIDAS Observatory/MNRAS

Early Friday morning, a streaking meteor illuminated the sky over Chelyabinsk, Russia. Seconds later, meteorite debris pummeled the city, injuring over 900 people . A shcokwave from the meteor's higher altitude explosions also cracked as it reached the ground and shattered glass windows. Below are a few videos of the incident as compiled by redditors "Therecanonlybetwo" and "hattmarington," respectively. The first video shows the meteor streaking across the sky from the view of a dashcam. The second video captured the booming shockwave's arrival on ground level and the subsequent damage.