Sky and Telescope 21 Sep 2017, 18:05 UTC Particles traveling at fair fractions of the speed of light hit Earth all the time. These ridiculously energetic entities, called cosmic rays, are protons and larger atomic nuclei from space. Their energies range from about a billion to beyond 10 million trillion electron volts (109 to 1020 eV), or up to 10 million times higher than the energy at which the Large Hadron Collider smashes protons together. (Incidentally, this is why we know the LHC won’t create dangerous microscopic black holes.) Astronomers think the lower-energy cosmic rays (which are far more common) come from within the Milky Way, particularly from star-forming regions and supernova remnants. The more energetic ones — we’re talking 1,000 trillion eV — are thought to come from outside the galaxy.
Scientific American 21 Sep 2017, 17:00 UTC The encounter will give the spacecraft a boost on its deep-space trip to fetch samples from the asteroid Bennu
Centauri Dreams 21 Sep 2017, 15:11 UTC If New Horizons can make its flyby of Kuiper Belt Object MU69 at a scant 3500 kilometers, our imagery and other data should be much enhanced over the alternative 10,000 kilometer distance, one being kept in reserve in case pre-encounter observations indicate a substantial debris field or other problems close to the object. But both trajectories, according to principal investigator Alan Stern, have been moved closer following a ten-week study period, and both are closer than the 12,500 kilometers the spacecraft maintained in its flyby of Pluto.
NPR 21 Sep 2017, 13:51 UTC A project called the Event Horizon Telescope is analyzing data taken earlier this year using interferometry — and we may be remarkably close to "seeing" a black hole, says astrophysicist Adam Frank.(Image credit: J.A. Biretta, Hubble Heritage Team/NASA)
SPACE.com 21 Sep 2017, 12:11 UTC NASA's New Horizons spacecraft is zooming through the outer solar system with its eyes open once again. New Horizons woke from a five-month hibernation period — its first stretch of rest since before its epic Pluto flyby in July 2015 — last week, right on schedule, mission team members said.
SPACE.com 21 Sep 2017, 12:00 UTC Not one but two gigantic black holes lurk at the heart of the distant spiral galaxy NGC 7674, a new study suggests. These two supermassive black holes are separated by less than 1 light-year and together harbor about 40 million times the mass of the sun, researchers said.
EarthSky Blog 21 Sep 2017, 11:53 UTC Brown researchers have found new evidence of ice sheets in permanently shadowed craters near the north pole of Mercury. Image via Head lab/Brown University. The scorching hot surface of Mercury – the closest planet to the sun – seems like an unlikely place to find ice, but research over the past three decades has suggested that frozen water hidden away on crater floors that are permanently shadowed from the sun’s blistering rays. Now, a new study led by Brown University researchers suggests that there could be much more ice on Mercury’s surface than previously thought. The study, by researchers from Brown University, published September 14, 2017 in Geophysical Research Letters, adds three new members to the list of craters near Mercury’s north pole that appear to harbor large surface ice deposits. The researchers estimate the total area of the three sheets to be about 3,400 square kilometers (1,313 square miles) — that’s slightly larger than the U.S. state of Rhode Island. In addition to those large deposits, the research also shows evidence that smaller-scale deposits scattered around Mercury’s north pole, both inside craters and in shadowed terrain between craters. Those deposits may be small, but they could add up to ...
EarthSky Blog 21 Sep 2017, 10:02 UTC In this image of Aeolis Dorsa, the dotted white arrow points to curved strata recording point bar growth and river migration. Stacked above the point bars and completely confined within the dotted white and black lines are topographically inverted river deposits outcropping as ridges (e.g., black arrow). In places (e.g., south of the dotted white arrow), the ridges run against the dotted boundaries, suggesting flow was once redirected along a valley wall. Image via GSA. River deposits exist across the surface of Mars, and record a surface environment from over 3.5 billion years ago that was able to support liquid water at the surface. That’s according to a study published in the September 2017 issue of the Geological Society of America’s GSA Bulletin. A region of Mars named Aeolis Dorsa contains some of the planet’s most spectacular and densely packed ancient river deposits. These deposits are observable with satellite images because they have undergone a process called “topographic inversion” – that is, deposits that once filled low river channels have been lifted up so that they now exist as ridges at the surface of the planet. With the use of high-resolution images and topographic data from cameras on orbiting satellites, ...
Universe @ CSIRO 21 Sep 2017, 04:18 UTC Radio astronomy is undergoing a major boost, with new technology gathering data on objects in our universe faster than astronomers can analyse. But once that data is scrutinised it could lead to some amazing new discoveries, as I explain in my review of the state of radio astronomy, published today in Nature Astronomy. Over the next few years, we will see the universe in a very different light, and we are likely to make completely unexpected discoveries.