Astronomy news

It's 'not' an icy snowball

At www.sciencenews.org/article/rosetta-may-have-spotted-comet's-primordial-... ... the rugged terrain of Comet Churyumov-Gerasimenko was the subject of a talk at the 2014 AGU annual meeting in San Francisco (December, 2014). It seems an onboard instrument has been taking some very close up photographs of the surface of the comet and this has revealed is is not a dirty snowball. Well, who'd have guessed that. More interesting, is the images also show cliffs on the comet that are 10s and 100s of metres in height - together with mysterious pits.

Space Waves

NASA, on 16th December, in a news release, said that the Voyager 1 spacecraft, at the edge of the solar system, had experienced three shock waves. The third of these began as along ago as February 2014 and is still in progress as we approach 2015.

A similar kind of shock wave is produced by the Sun when it emits a coronal mass ejection, throwing out a cloud of plasma, generating a wave of energy. A video clip can be seen at www.jpl.nasa.gov/news/news.php?feature=4411. See also www.jpl.nasa.gov/video/details.php for a full list of videos on a variety of space subject.

Asteroids and Meteors

At http://phys.org/print338024091.html ... below is an image of cliffs on Comet Churyumov-Gerasimenko, processed by one Stuart Atkinson. The cliff is nearly verticle

   See also www.esa.int/Our_Activities/Space_Science/Rosetta/Comet_67P_Churyumov-Ger...

At http://phys.org/print337934945.html ... below we have another image, this time it is of the Chelyabinsk meteor of 2013 seen leaving a trail in the sky over some houses

67P and counting

Comet Churyumov Gerasimenko, known also as 67P, is almost as black as coal - but images show it as grey - see http://phys.org/print337631011.html ... This is a halfway mix between black and the white dots on the surface produced by ... we not what as yet. The image has been enhanced in order to show up surface details and black hides a lot detail. Apparently, there is no indication of icy patches on the surface of the comet - but the surface does have a dark dust, or crust. At http://phys.org/print334505509.html ... we have images of the comet in early November - prior to the lander.

Rosetta, are you wetter

At http://blogs.esa.int/rosetta/2014/11/07/virtis-detects-water-and-carbon-... ... as the data is being processed and we may have to wait a while for sound evidence it is worth going back on what was being said as Rosetta approached the comet in November (prior to the Philae lander getting everyone excited). The comment thread appears to have been usurped by EU enthusiasts - and you can keep up to date with the subject of what the comet is composed of at Thunderbolts forum.

A firewall in space

At http://phys.org/print336218352.html ... an invisible shield 7200 miles above the surface of the Earth appears to block dangerous electrons - a sort of protection from the solar wind and its excesses. Professor David Baker, who earned his doctorate under Van Allen and has maintained an interest in the Van Allen belts, two doughnut shaped rings above the Earth, went on to discover a third but transient ring (reported a year or so ago) situated between the two permanent rings. The new transient ring comes and goes according to space weather.

Siding Spring update

At http://phys.org/print336388496.html ... the approach of comet Siding Spring to the planet Mars a few weeks ago has now been updated by including images and data from the Indian space mission to Mars. A streak appears to radiate out of the comet's nucleus and it is this ejection of dust and gas that might have caused the meteor storm - but again, it may have nothing to do with dust or gas. At the same time, it is being suggested by NASA that this was a one in 8 million years event - quite how they arrive at that estimate is left unsaid.

Rosetta Update

At http://phys.org/print335689483.html ... the spacecraft is still orbiting the comet but is not in contact with the probe. However, it is able to continue with its own research, gathering data. In the long term it is hoped that Rosetta will be around long enough to witness the development of the comet's coma - as it get closer to the Sun.

The Sun and Lightning

At http://phys.org/print335609396.html ... we are told the Sun may be playing a part in the generation of lightning strikes on Earth by temporarily bending the Earth's magnetic field and allowing a shower of energetic particles to enter the upper atmosphere. Researchers from Reading University have been looking at this for some 5 years and their findings have been published in the journal Environmental Research Letters (this month).

What Gravity did for us

We all know what the Romans did for us - they created the border between Scotland and England. What did gravity do for us? It saved the universe according to a new scientific paper - see http://phys.org/print335524004.html It's all about Big Bang dynamics, the Higgs Bosun particles - and the expansion of the universe.