Astronomy news

Dilation of Time

At http://phys.org/print339147471.html ... there is a fascinating abstract derived from an article in the December 23rd issue of PLOS ONE online journal, 'Implication of an Absolute Simultaneity Theory for Cosmology and Universe Acceleration' which suggests dark energy is not necessarily a factor in the expansion of the universe. It is all about the idea of time dilation and a different way of looking at Einstein's theory of relativity.

Forbush Decrease

A sudden decrease in cosmic rays bombarding the Earth's atmosphere has coincided, accidentally or otherwise, with a week or so of very cold weather. On December 21st ground based neuton monitors detected a sudden decrease in cosmic radiation - http://spaceweather.com December 29th - and this was due to three CMEs thrown out by the Sun, over the previous 48 hours, sweeping away, broom like, many of the cosmic rays normally in the vicinity of the Earth. The CMEs did not engage with the Earth or its atmosphere - they swept on by (sweeping up the cosmic rays in the process).

Venus is still mysterious

At http://phys.org/print338201746.html ... we have one of those schoolboy visions of Venus which is mostly hypothetical but written as reality. Venus is horrible! It sucks, we are told - but sucks what? It's as hot as an oven (actually, an awful lot hotter than an oven) and atmospheric pressure is 90 times that of the Earth. It rains sulphuric acid. It is a lethal place as far as humans are concerned - so no bus stops for spaceship tours on Venus. We won't be visiting the place in a hurry.

Sizzling Sun

At www.jpl.nasa.gov/news/news.php?release=2014-440 ... we have this picture of the Sun

X-rays streaming off the Sun. This is the first picture of the Sun by NASAs nuclear spectroscopic telescope array (NuSTAR). It was designed to look into deep space in order to study x-rays from black holes and supernovas etc. It was launced in 2012 but only now has it been turned around to focus on the Sun.

Polar Stratospheric Clouds

    these beautiful cloud formations are visible inside the Arctic Circle, floating in the lower stratosphere at 25km high - and they are full of colours. Go to http://spaceweather.com December, 2014, for lots of images of aurorae, meteors, and noctilucent clouds etc. It is thought polar stratospheric clouds are formed by sunlight shining through tiny ice particles.

Horse Head

The Horse Head nebula as once seen and diffused by NASA

but here it is again, diffused by infra red

see http://phys.org/print338453527.html

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.