Black Holes and a Rusty Moon

4 Sep 2020

At ... a new study questions decades of research on the evolution of spiral galaxies. This might be a game changer, as they say. A new technique has been used for a fresh look at spiral galaxies. In one third of those looked at the disc beneath the bulge does not preserve its exponential profile, but instead, a central flattening, or decrease, is found. This seems to imply the amount contributed from disc and bulge stars to the galaxy centre is different than previously stated in a substantial number of studies that assume an exponential increase up to the centre of the disc. Note the word assumption. Lots of assumptions litter science studies. This is not unusual. In other words, previous studies in sprial galaxy evolution, may be flawed by assuming that the brightness contributed to stars intrinsic to the bulge is less significant than it is. This seems to mean the stars brightness has been underestimated. For example, in spiral galaxies in which the disc represents 80 per cent of luminosity in the central area, its over estimation may lead to erroneous classification of the bulge. This has furher implications when dealing with galaxies with intense activity in their cores - associated with the presence of a super massive black hole. These inhabit the so called galactic nucleus. It might lead to a change in the mass correlation between bulge and black holes and place constraints on galaxy formation models. The key word here of course is 'might' - which might not of course.

Gary sent in a link to ... iron on the moon is rusting due to oxygen blown in on the solar wind. Oxidised iron, the mineral hematite, was discovered on the moon by planetary scientists - by analysing data from the Indian Chandrayaan 1 Mission. Iron is highly reactive with oxygen, forming the rust we see here on the earth. However, the lunar surface is devoid of oxygen. How then does hematite form on the moon. They explored if it was possible that water in lunar rocks, or beneath the surface, was responsible - which is  still a possibility. Hematite seems to be located on the near side of the moon, facing the earth. The key, may then exist on earth - and was transported to the moon. The researchers then refer to the Japanese lunar Kaguya Mission that found that oxygen from earth's atmosphere can be blown to the moon's surface by the solar wind when the moon is in the earth's magnetotail. Oxygen  could be the major oxidant although water and space dust may also play a role.

At ...  the universe seems to be humming with activity - in the form of gravitational waves. Is this telling us something about the theory? It seems, since gravitational waves hit the headlines a matter of months ago, astronomers have been finding them everywhere. They are jumping out of the sky from all over the place. These reverberations ripple forth and shake the fabirc of space time, we are told, like the clang of a cosmic bell. Researchers claim to have detected one such from a black hole merger - the mainstream preferred interpretation. The signal lasts just one tenth of a second. Computer simulation and models are used to reach the conclusion that black holes are the heart of the matter. Let's hope, for their sake, the so called state of the art models, are more authentic than climate models.

See also ... did meteorite impacts help create Life on Earth and beyond?