Astronomy

Thanu Padmanabhan asks: Our knowledge about the universe has increased tremendously in the last three decades or so — thanks to the progress in observations — but our understanding has improved very little. There are several fundamental questions about our universe for which we have no answers within the current, operationally very successful, approach to cosmology. Worse still, we do not even know how to address some of these issues within the conventional approach to cosmology. This fact suggests that we are missing some important theoretical ingredients in the overall description of the cosmos. I will argue that these issues — some of which are not fully appreciated or emphasized in the literature — demand a paradigm shift: We should Read More ›

Sometimes, it is important to go back to key sources, if we are to break through deep misconceptions.  This is particularly relevant for the design view of science, including on cosmological fine tuning. So, first Sir Fred (a key discoverer of the phenomenon): >>[Sir Fred Hoyle, In a talk at Caltech c 1981 (nb. this longstanding UD post):] From 1953 onward, Willy Fowler and I have always been intrigued by the remarkable relation of the 7.65 MeV energy level in the nucleus of 12 C to the 7.12 MeV level in 16 O. If you wanted to produce carbon and oxygen in roughly equal quantities by stellar nucleosynthesis, these are the two levels you would have to fix, and your Read More ›

From Nick Allen at Telegraph: US President-elect Donald Trump is set to slash Nasa’s budget for monitoring climate change and instead set a goal of sending humans to the edge of the solar system by the end of the century, and possibly back to the moon. … According to Bob Walker, who has advised Mr Trump on space policy, Nasa has been reduced to “a logistics agency concentrating on space station resupply and politically correct environmental monitoring”. … Its funding has gone up 50 per cent under President Barack Obama. At the same time Mr Obama proposed cutting support for deep space exploration by $840 million next year. More. Well, if They’re out there, We’ll find them. See also: Rob Read More ›

Most perplexing mystery in astronomy. From Elizabeth Gibney at Nature: What causes split-second blasts of radio waves that appear in the sky from billions of light years away is one of the most perplexing mysteries in astronomy. Now, for the first time, astronomers have seen a flash of high-energy γ-rays [gamma rays] that looks as if it was emitted by the same event that produced a fast radio burst (FRB) — a correlation that was predicted to help whittle down the zoo of possible explanations for the origin of FRBs. “If FRBs have γ-ray counterparts, it would be hugely constraining of models and extremely interesting,” says Victoria Kaspi, an astrophysicist at McGill University in Montreal, Canada. But as well as exciting Read More ›

From Daniel Stolte at University of Arizona News: Sputnik Planitia, a 1,000-kilometer-wide basin within the iconic heart-shaped region observed on Pluto’s surface, could be in its present location because accumulation of ice made the dwarf planet roll over, creating cracks and tensions in the crust that point toward the presence of a subsurface ocean. Published in the Nov. 17 issue of Nature, these are the conclusions of research by James Keane, a doctoral student at the University of Arizona’s Lunar and Planetary Laboratory, and his adviser, assistant professor Isamu Matsuyama. They propose evidence of frozen nitrogen pileup throwing the entire planet off kilter, much like a spinning top with a wad of gum stuck to it, in a process called Read More ›

Leonid Meteor Shower: In mid-November, spectacular “shooting stars” will streak through the night sky as the Leonid meteor shower hits Earth once again. This annual meteor shower is responsible for some of the most intense meteor storms in history, with meteors falling at rates as high as 50,000 per hour. This year’s Leonid meteor shower won’t be quite as impressive, though, said NASA meteor expert Bill Cooke. “This year, the Leonids are not in outburst, so the rates are going to be about 10 to 15 per hour,” he said. Outbursts occur when the Earth passes through a particularly dense patch of meteors. [Top 10 Leonid Meteor Shower Facts] Sure, but the show is free.

  From Elizabeth Howell at Space.com: November’s full moon on Monday (Nov. 14) will be the biggest and brightest one since 1948, making it a great time to get outside and marvel at the lunar sight for stargazers around the world. But if it happens to be cloudy in your area, don’t despair. You can still watch the so-called “supermoon” online in several live webcasts, starting tonight (Nov. 13). More.

From Astronomical Journal: In order to search for evidence of hydration on M-type asteroid (16) Psyche, we observed this object in the 3 micron spectral region using the long-wavelength cross-dispersed (LXD: 1.9-4.2 micron) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). Our observations show that Psyche exhibits a 3 micron absorption feature, attributed to water or hydroxyl. The 3 micron absorption feature is consistent with the hydration features found on the surfaces of water-rich asteroids, attributed to OH- and/or H2O-bearing phases (phyllosilicates). The detection of a 3 micron hydration absorption band on Psyche suggests that this asteroid may not be metallic core, or it could be a metallic core that has been impacted by carbonaceous material Read More ›

From Joshua Sokol at New Scientist: The problem was that the Boötes void was just too big. Voids grow because their dense edges have a much stronger gravitational pull than anything at their centres. But the universe wasn’t yet old enough to have inflated such a big bubble. For an explanation, we had to wait until the 1998 discovery of dark energy: a cosmic pressure that forces empty regions of space to expand as if someone was blowing air into each of the universe’s soap bubbles all at once. Many astronomers, now in a boom of cataloging and mapping voids, think these spooky regions that expose the naked fabric of the universe could point to the next big discovery. More. But Read More ›

From Charles Q. Choi at Space.com: New craters are forming on the surface of the moon more frequently than scientists had predicted, a new study has found. The discovery raises concerns about future moon missions, which may face an increased risk of being hit by falling space rocks. The moon is dotted with a vast number of craters, some billions of years old. Because the moon has no atmosphere, falling space rocks don’t burn up like they do on Earth, which leaves the moon’s surface vulnerable to a constant stream of cosmic impacts that gradually churn the top layer of material on its surface. You can see a before-and-after video of a new moon crater here.More. From New Scientist: The Read More ›

From Nola Taylor Redd at Space.com: Although planets surround stars in the galaxy, how they form remains a subject of debate. Despite the wealth of worlds in our own solar system, scientists still aren’t certain how planets are built. Currently, two theories are duking it out for the role of champion. The first and most widely accepted theory, core accretion, works well with the formation of the terrestrial planets like Mercury but has problems with giant planets. The second, the disk instability method, may account for the creation of these giant planets. Now, as for Mercury: Like Earth, the metallic core of Mercury formed first, and then gathered lighter elements around it to form its crust and mantle. Mercury, like Read More ›

From Space Telescope.org: The Hubble eXtreme Deep Field— and more The Hubble eXtreme Deep Field (2012) combines all previous observations of the Hubble Ultra Deep Field Published in 2012, the Hubble eXtreme Deep Field is not a new set of observations, but rather a combination of many existing exposures (over 2000 of them) into one image. Combining the Hubble Ultra Deep Field, the Hubble Ultra Deep Field – Infrared, and many other images of the same small spot of sky taken over almost 10 years, the Hubble eXtreme Deep Field pushes the limit even further. It is made up of a total of 22 days of exposure time (and 50 days of observing time, as the telescope can only observe Read More ›

From Brian Clark Howard at National Geographic News: Published in the journal Science Advances this week, a new study reported that our surrounding area of stars, gas, and dust—called the Local Arm, Orion Spur, or Orion–Cygnus Arm—is actually about 20,000 light-years long. The immediate implications are that the galaxy is actually a little more symmetrical and regular than scientists previously thought, says one of the study’s co-authors, Mark J. Reid of the Harvard-Smithsonian Center for Astrophysics. Although a better understanding of our galaxy’s structure doesn’t necessarily mean gravity or other forces acting on us are different from what we expect, it could help us better understand large-scale features in the future, notes Reid. More. See also: Cosmologist Luke Barnes on Read More ›

Starting this month. From Ross Logan at UK Mirror: The Five-hundred-metre Aperture Spherical Telescope (FAST) will search deep space in the hope of unlocking some of the universe’s deepest secrets Is Earth finally about to make contact with extra terrestrial life? That is one of the hopes for the world’s largest radio telescope, which will be switched on later this month. The finishing touches have now been put to the Five-hundred-metre Aperture Spherical Telescope (FAST), in south west China’s Guizhou Province, with the enormous 1,650-foot-wide dish set become operational from September 25. More. Good hunting! But one question that arises is, how do we know at what point we can come to a conclusion? See also: How do we grapple Read More ›

From Belinda Smith at Cosmos Magazine: Around 4.5 billion years ago, an object slammed into Earth vaporising most of the planet into a scorching cloud from which the moon was born. Geochemists in the US – Kun Wang from Washington University in St Louis and Stein Jacobsen at Harvard – examined minuscule amounts of potassium in moon and Earth rocks and found minute differences – possible only if their raw materials were thoroughly mixed in a superheated fog before they coalesced. The work, published in Nature, pokes a hole in the theory that the moon was born from a low-impact collision. More. In truth, we do not know very much about how the moon was formed, and theories rise and Read More ›