Starts With a Bang! 10 Nov 2018, 15:01 UTC Nothing in the Universe lives forever. All the stars that will ever form will someday burn out; distant galaxies and clusters of galaxies get pushed away from one another by dark energy; even the stars within a galaxy, on long enough timescales, will get gravitationally ejected. At the centers of galaxies, though, the largest single objects in the Universe form and grow even today: supermassive black holes. The most massive ones contain tens of billions of solar masses in a singularity surrounded by an event horizon, making them the most massive individual entities we know of. But even they won’t live forever, and Jim Gerofsky wants to know what happens to cause them to die, asking: [J]ust what is Hawking radiation? The science press articles keep referring to the electron-positron virtual pair production at the event horizon, which makes a lay person think that the Hawking radiation consists of electrons and positrons moving away from the black hole. As discovered by Stephen Hawking in 1974, black holes eventually evaporate. This is the story of how.
Astro Bob 10 Nov 2018, 05:24 UTC What looks like a red rash on this image are “hot spots” caused by heat from fires sensed by the orbiting Suomi NPP satellite. But wait. What’s that odd dot off the coast of Brazil in the middle of the Atlantic Ocean? Can’t be a fire, and it’s not a volcano or a natural gas flare. Scientists working with the satellite think it’s almost certainly connected to SAMA.
Astrobiology Magazine 9 Nov 2018, 21:00 UTC Ralph, one of NASA’s most well-traveled space explorers, has voyaged far and accomplished much.
Centauri Dreams 9 Nov 2018, 20:12 UTC After the Parker Solar Probe’s close pass, the spacecraft has gone nearer the Sun than any other craft. The Helios B probe was the previous recorder holder, setting the mark back in 1976. Helios B reached perihelion in April of 1976 at a distance of 43.4 million kilometers (26.9 million miles), inside the orbit of Mercury. A record the Parker probe surpassed with ease.
NASA Space Station Blog 9 Nov 2018, 18:27 UTC A crew of three from around the world are heading into the weekend aboard the International Space Station. The Expedition 57 trio from the United States, Russia and Germany studied a variety of space phenomena today including physics, biology and time perception.
Starts With a Bang! 9 Nov 2018, 15:01 UTC One of the most profoundly remarkable properties about our atmosphere is that it’s transparent to not only sunlight, but to starlight as well. As we turn our eyes skyward after the Sun goes down, a glittering tapestry of planets, stars, galaxies, and nebulae illuminates the heavens. If we want to view it, all we have to do is look with the proper tools. But our view of what’s out there, from here on Earth, is limited in ways we rarely think about. Even on a cloudless night, any light coming to us from space must pass through over 100 kilometers (more than 60 miles) of atmosphere, which itself has continuous variations in density, temperature, and molecular composition. Any light coming in has to contend with the atmosphere, and even though the atmosphere is transparent, that light inevitably gets distorted. For the first time, astronomers are finally capable of overcoming Earth’s atmosphere. Here’s how.
Many Worlds 8 Nov 2018, 20:49 UTC In the known history of our 4.5-billion-year-old solar system, the insides of but one planet have been explored and studied. While there’s a lot left to know about the crust, the mantle and the core of the Earth, there is a large and vibrant field dedicated to that learning. Sometime next month, an extensive survey of the insides of a second solar system planet will begin. That planet is Mars and, assuming safe arrival, the work will start after the InSight lander touches down on November 26.