In 2016, astronomers using data from NASA’s Kepler mission, discovered a planet unlike anything in our solar system –a “water world” planetary system orbiting the star Kepler-62 –a five-planet system with two worlds in the habitable zone — their surfaces completely covered by an endless global ocean with no land or mountains in sight.
The Milky Way is a dynamic museum of ancient merging relics, river-like streams of stars stripped from dwarf satellite galaxies that flow through the galaxy revealing its history and structure that allow astronomers to better understand how galaxies in the universe have formed and evolved.
In 1993 Stephen Hawking proposed in Black Holes and Baby Universes that there might be “primordial black holes which were formed in the early universe that could be less than the size of the nucleus of an atom, yet their mass could be a billion tons, the mass of Mount Fuji. A black hole weighing a billion tons,” Hawking explained, “would have a radius of about 10-13 centimeter (the size of a neutron or a proton). It could be in orbit either around the sun or around the center of the galaxy, emitting hard gamma rays with an energy of about 100 million electron volts.”
Hubble astronomers found something extraordinary at the heart of nearby globular cluster NGC 6397 –a concentration of smaller black holes lurking there instead of one monster, supermassive black hole. Ancient stellar jewelry boxes, globular star clusters are densely packed objects, glittering with the light of a million stars in a ball only about 100 light-years across dating back almost to the birth of the Milky Way.
Our sun is travelling around the center of the Milky Way at 220 kilometers per second, says Gerry Gilmore with the Institute of Astronomy at the the University of Cambridge, referring to the fact that our Milky Way Galaxy lies inside a sphere, or “halo”, of dark matter that extends out far beyond the luminous Galactic disk, surrounded by a spheroidal halo of old stars and globular clusters, of which 90% lie within 100,000 light-years of the Galactic Center. “If there were no dark matter there, adds Gilmore, if there were just stars, we would be travelling at a ‘mere’ 150 km per second,” Gilmore adds. (more…)