Astronomy news

Big Bang Revision

At http://phys.org/print298800472.html ... some scientists are proposing a revision of Big Bang. They say the birth of the universe may have happened after a four dimensional star collapsed into a black hole and ejected debris. It came about as there are problems with the current Big Bang theory - in their opinion. The universe appears to have a uniform temperature but the age of the universe, a mere 13.5 billion years, does not give enought time to reach a temperature equilibrium. Or something like that. The article is at www.arxiv.org/abs/1309.1487

Dark Matter and Lunar Tides

At www.dailygalaxy.com/my_weblog/2013/09/dwarf-galaxies-found-to-harbor-100... ... and the title of the post says it all. Modelling of telescope observations, which sounds like a paradox, was used to determine that in some galaxies dark matter decreased from centre outwards but in others it was more or less constant.

Noctilucent

In Northern Earth 135 (autumn, 2013) there is a little piece with the title, 'what would our ancestors make of this?' which set me thinking. Noctilucent clouds are ripples in the sky, in the mesosphere (50 miles upwards) and they tend to be visible in the first hour after sunset (during the twilight zone). They form on the smoke trails of meteors burning up as they enter the atmosphere leaving a layer of particles on which moisture can form reflective crystals.

Voyager out of the solar system

NASA has released information on the current status of Voyager 1 and the spacecraft has moved into interstellar space, is the claim. It is 12 billion miles from the Sun and it seems over the last year it has been travelling through plasma or ionised gas, present in the space between stars. Voyager is still in the transition zone but is actually outside the solar bubble. See www.jpl.nasa.gov/news/news.php?release=2013-277&cid=release_2013-277

Resurrection in Space

At http://phys.org/print298024131.html ... the quixotically named Don Quixote asteroid, the third largest Near Earth Object (or NEO), has changed status. It is now regarded as a comet. Such dead comets are thought to have shed all their water and carbon dioxide in the form of ice that gave them their coma and tail - it is thought that when approaching the vicinity of the Sun comets emit lots of dust and water ice as a result of heat.

Two rates of expansion and the zodiacal lights

At http://phys.org/print297931761.html ... measuring the speed the Universe is expanding has come up with a problem. The mainstream view is that the observable universe has been expanding since the Big Bang and the speed of this is known as the Hubble Constant - but how fast is the rate of expansion? Measuring cosmic microwave background radiation has been the accepted methodology until recently. The Planck satellite, belonging to the ESA, delivered a different rate of exapansion several months ago which has caused a problem.

Seeding the Earth

At www.sciencenews.org/view/generic/id/353090/description/Meteorite_that_fe... ... the meteorite that fell last year grounded in California. After melting away some minerals with acid a number of sulphur and oxygen containing organic compounds were left behind, several of which have never been identified in meteorites previously (PNAS, September 9th). The molecules possibly formed at the same time as the early Earth, warm and rich in water.

Catching Up

At http://phys.org/print297333060.html ... is a piece on Brown Dwarf stars and why they might have failed to become bright Sun like objects. There are of course theoretical uncertainties in understanding brown dwarfs, we are told.