Astronomy news

Comets ... Halley as Jupiter

At www.physorg.com/print252088815.html ... is Comet Wild2 subject to space weathering, is the question being asked, but it is a reference to a rusty red colouration on its surface. Microfocus Spectroscopy has shown Wild2 has been bombarded by particles in the solar wind and by micrometeorites for a long time, depositing grains of iron and reddening the surface (or that is the current thinking).

Harmony in the solar system

A paper by Nicola Scafetta in the Journal of Atmospheric and Solar-Terrestrial Physics is bound to get alarmists in a tangle - see http://tallbloke.wordpress.com/2012/03/21/nicola-scafetta-major-new-pape... ... the abstract of the online paper says the Schwabe frequency band of the Zurich sunspot numbers between 1749-2011 is found to contain three major cycles in periods of 9.98, 10.9 and 11.86 years. The frequencies appear to be closely related to the spring tidal periods of Jupiter and Saturn, and the tidal sidereal period of Jupiter.

Mercury - and polar wandering

Mercury is throwing up some surprises according to a paper in Science - see www.physorg.com/print251643931.html. For example, it has an iron core that comprises approximately 85 per cent of the planet's radiance. Mercury's mantle and crust occupy the outer 15 per cent. The authors also speculate that polar wandering has taken place on Mercury - something out of bounds as far as the Earth is concerned. They even mention redistribution of mass - reshaping the geoid.

The Sun and the Asteroid

At www.physorg.com/print251533118.html ... a piece on sunspots and solar flares and an image of a solar flare from March 13th. The flare is described as a burst of radiation yet goes on to say the radiation is derived from the release of magnetic energy.

NASA mission to the Sun

At www.physorg.com/print251143024.html ... namely, the Solar Probe Plus mission and a piece of electronic wizardry being assembled by Justin Kasper - eyes across 100 million miles of space. Within 7 years the planned mission will journey to the centre of the solar system in order to study the solar wind. It will address key points - how does the corona heat to a phenomenal degree and what powers the solar wind, the stream of charged particles that flows from the corona.

Near Miss to Miss us again

At www.physorg.com/print251104689.html .... we learn that the asteroid that came close to earth earlier in the year will do the same thing next year. Known as 2012 DA14 it has an orbit synchronised with that of the earth's orbit - and it jumps inside and outside of the path of the earth two times a year.

WISE mapping

At www.sciencedaily.com/releases/2012/03/120313163921.htm ... 'flying through a geomagnetic storm' is an astronaut onboard the International Space Station commenting on what he can see as he flies over the auroral light show.

Dione

The Cassini spacecraft has detected a thin atmosphere that includes oxygen and ozone on Saturn's moon, Dione - see www.jpl.nasa.gov/news/news.cfm?release=2012-056&cid=release_2012-056. Admittedly, it is a faint atmosphere but enough to get news of it published in Geophysical Research Letters. Oxygen, it seems, is common in the Saturn system, already detected on the moon Rhea and in the rings around the planet.

Fireballs in February

At http://fireballs.ndc.nasa.gov there is information on fireballs over North America - and presumably elsewhere too. The story can also be seen at www.physorg.com/print249203167.html and it seems that in this february just gone there were some rather large space rocks entering the atmosphere of the earth. They were peculiar in that they were slow and penetrated much further and deeper than they are prone to do, breaking up closer to the surface. The origin of them is also somewhat puzzling as they have different orbits and trajectories.

Titan

At www.jpl.nasa.gov/news/news.cfm?release=2012-048&cid=release_2012-048 there is some interesting information available about Saturn's moon, Titan, the subject of a number of papers in the science press recently. The Cassini spacecraft has beamed back some wonderful images and has shown how Titan's atmosphere resembles that of the earth - with clouds, rainfall, and river valleys, lakes and other geological characteristics that have surprised astronomers to a certain degree.