A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP), using state-of-the-art theoretical models. The new study shows that groups of stars with the same age always flare as the result of massive galactic collisions. When taken all together, these flares, nested like the petals of a blooming rose, puff up the disk and constitute what astronomers call the "thick" disk.
The supermassive black hole is 40 million times as massive as the sun and powers a quasar that existed 700 million years after the Big Bang.
The asteroid zoomed by Earth at a perfectly safe distance of around 1.8 million miles (2.9 kilometers).
Images show surprise changes to the spacecraft as it interacted with the atmosphere.