Dark Matter - is it there or is it not there?

26 Apr 2012

The invisible ingredient of the universe is taking a pounding this week. At http://phys.org/print254566203.html ... German astronomers have discovered vast structures of satellite galaxies and clusters of stars surrounding the Milky Way, as if there had been some kind of collision between galaxies some time in the past and pieces of one of them had attached themselves to the orbit of our galaxy. Of course, there might well be some other kind of explanation - but this is what the German researchers are suggesting in the paper published in Monthly Notices of the Royal Astronomical Society. The very presence of them challenges the existence of dark matter as the space in space is being squeezed too tightly to accommodate it. Apparently, there are 3,000 million stars plus gas and dust arranged on a flat disc with arms that wind out from a central bar - in the Milky Way. Looking outside the box of our galaxy a number of smaller galaxies and spherical clusters of stars orbit with the Milky Way - but outside it's basic structure. Consensus astro-physics says there is about 23 per cent of dark matter but it seems there is not the room to accommodate it - or that is what is being suggested. Are the cosmology models wrong?

Meanwhile, at www.jpl.nasa.gov/news/news.cfm?release=2012-117&cid=release_2012-117 ... the Dawn spacecraft has new images of asteroid Vesta including surface composition and clues to internal structures. One sentence stood out - 'breccias, which are rocks formed during impacts from space debris ....' - what does NASA mean? Is it just breccias on Vesta that were formed by impacts or are they suggesting breccia formations on Earth likewise were formed by impact. If so, this would mean reinterpreting some basic geology. Also, NASA say that various layers on Vesta were blasted away in such impact events - again, can this thinking be transferred to the Earth. Large strips of recent geology are missing from almost any point on Earth, assumed to be eroded by wind, water or ice. Is it possible some of the stripping away of geological strata has a different origin than simply erosion. Might that be a seismic change in thinking? It sounds all a bit like some of the speculative geology we can see on the Thunderbolts web site, www.thunderbolts.info , such as Picture of the Day, where readers are told that electric discharges are to blame. Is NASA saying that a similar kind of thing could be attributed to blast and melt? I've probably read too much into this but if they are seriously saying it can happen on an asteroid orbiting in space why cannot something similar happen on Earth, orbiting in space and coming into contact with space rocks etc. The only difference, is that Vesta is orbiting in the so called 'asteroid belt' and impact is assumed to have been a regular feature of it's past. The consensus is that the Earth has not been subject to such a bombardment - not in the last hundreds of millions of years?