Astronomy

A friend recommends this fun vid about the scale of our solar system, made by self-described “highly intelligent goofballs.” Follow UD News at Twitter!

The Japanese National Institutes of Natural Sciences (NINS) are reporting about new research that throws a small wrinkle into the search for life on planets outside our solar system. Such bodies, known as “exoplanets,” have emerged as one of the more exciting areas of astronomical study — an entire new field of research having essentially arisen in little more than two decades and now occupying many full-time researchers, several earth-bound telescopes, and even dedicated space missions. Early results have been impressive, with the improvements in sensor technology matched by the exponential increase in discovered bodies. After the first lone exoplanet was discovered around a main sequence star in 1995, a small trickle of additional exoplanets were discovered. Then the trickle Read More ›

From RealClearScience: The pebble accretion model, as the idea is called, suggests that tiny objects first coalesce together due to drag then gravitationally collapse and form larger objects one hundred to one thousand kilometers in size. These larger objects, now referred to as planetesimals, than draw in all the remaining pebbles and become the cores of larger planets. Simulations completed last year cast doubt on this interesting theory. They suggested that — in the context of our solar system — too many planetesimals would form — as many as one hundred objects the size of Earth! Since our Solar System only contains eight planets and five recognized dwarf planets, this theory was mostly ruled out. However, a new simulation carried Read More ›

If they do: Astronomers are constantly uncovering the “most distant,” “most massive” or “most energetic” objects in our universe, but today, researchers have announced the discovery of a truly monstrous structure consisting of a ring of galaxies around 5 billion light-years across. … Astronomers believe these GRBs (and therefore the galaxies they inhabit) are somehow associated as all 9 are located at a similar distance from Earth. According to its discoverers, there’s a 1 in 20,000 probability of the GRBs being in this distribution by chance – in other words, they are very likely associated with the same structure, a structure that, according to cosmological models, should not exist. Where have we heard this before? Copernicus, you are not going Read More ›

From Eurekalert: The team, led by UA astronomer Peter A. Milne, discovered that type Ia supernovae, which have been considered so uniform that cosmologists have used them as cosmic “beacons” to plumb the depths of the universe, actually fall into different populations. The findings are analogous to sampling a selection of 100-watt light bulbs at the hardware store and discovering that they vary in brightness. “We found that the differences are not random, but lead to separating Ia supernovae into two groups, where the group that is in the minority near us are in the majority at large distances — and thus when the universe was younger,” said Milne, an associate astronomer with the UA’s Department of Astronomy and Steward Read More ›

Here. REMEMBER PLUTO? TINY lonely rock orbiting the sun at the edge of the solar system? And then, in 2006, researchers summarily defrocked the little world of its status as a planet. Poof! Gone. This kind of thing has happened before. Many decades ago, paleontologists similarly decided that there wasn’t enough evidence to support the existence of the beloved Brontosaurus. Instead, they said that the noble thunder lizard was just an Apatosaurus. Poof. But mourn the Brontosaurus no longer! A team of heroes may have rescued it from paleontological purgatory. By cross-referencing the digitized bones from hundreds of long-necked cousins, a team of European scientists now says that they’ve identified enough unique anatomical details to reinstate the Brontosaurus at the Read More ›

Long-time visitors or regulars at UD will know that (along with StephenB who drew the significance to my attention . . . ) I champion the idea of self-evident, plumb-line first principles of right reason: That is, if we contemplate say a bright red ball on a table, we see a world-partition: W = { A | ~A } . . . which leads to manifesting the classic laws of identity [A is A not non-A], non contradiction [(A AND ~A) = 0] , and excluded middle . . . this, best expressed as (A X-OR ~A) = 1. Likewise, I have argued for a weak-form principle of sufficient reason. Contemplating that ball on the table, it is natural to Read More ›

The most common explanation for the formation of planet Earth is that it formed by gravitational collapse from a cloud of particles (gas, ice, dust) swirling around the Sun.  Specifically, the idea is that small planetesimals form as the various particles clump together (perhaps initially by cohesion, then by gravity), eventually growing into planets.  Known as the “accretion hypothesis,” this is the standard model of planet formation, not just for Earth, but for nearly all planets.* Significant debate continues regarding the formation of the Moon, but the most widely-held hypothesis is that the Moon formed in a similar way via accretion of impact material produced by a violent collision between a Mars-sized object and the Earth. For purposes of the Read More ›

Slightly off topic from the regular fare, but firmly in the ‘cool science stuff’ category. Photo of the partial eclipse this afternoon, taken in front of our house, with massive sunspot region 12192 visible near center: Equipment: Panasonic DMC-ZS3 with a Starmax 127EQ telescope and solar filter.  Also required: patience. I’m pretty happy with how it turned out, but it was a bit of a pain to get a good shot.  I think I’ll need to buy a decent camera mount soon . . .

Having read the recent post here on where Earth’s water came from, I just stumbled across an interesting article over at ExtremeTech.com from June of this year, evidently commenting on a find that was originally reported in Science (at least, that’s what I’ve gathered from reading a bit about it elsewhere). I’m not sure if anything came of this or if it was mentioned here and I missed it (I couldn’t find it in a search), but I thought it might spark some interesting discussion. From the article, titled Scientists discover an ocean 400 miles beneath our feet that could fill our oceans three times over: After decades of theorizing and searching, scientists are reporting that they’ve finally found a massive reservoir of Read More ›