Astronomy news

Bolide Events 1994-2013

NASA released the map below that reveals that small asteroids frequently enter and disintegrate in the Earth's atmosphere with a random distribution around the world. It is a visualisation of data gathered by US sensors over a 20 year period - some 556 occurrences of fireball activity.

 

Comet behaving like a comet

At www.dailygalaxy.com/my_weblog/2014/11/mars-once-in-a-million-years-comet... ... is another report on the NASA release on Comet Siding Spring from data produced by their MAVEN mission to Mars. Debris from the comet caused an intense meteor shower and enabled a new layer of ions, or charged particles, to the atmosphere of Mars. From observational data NASA scientists were able to make a direct connection between the input of the debris and the ions.

galactic corpses

At http://phys.org/print334486790.html ... we learn there is a mystery at the heart of our galaxy, the Milky Way. It has lots of gas, dust, and a huge black hole three million times the size of our Sun, but it has no pulsars - the corpses of dead stars. It is thought a lot of pulsars should exist at the galactic centre as stars form, thrive, and die - much like us. Eyes are being drawn towards the black hole - has it been munching on pulsars?

Going back to Comet Siding Spring's brush with Mars

Not a lot of information has come out of NASA on the recent close passage to Mars by Comet Siding Spring. However, at www.spaceweather.com on November 7th (scroll down if necessary) you will find a short bit taken from a NASA press conference. It resulted in a heavy meteor shower with an origin in the comet - and this is described as the highlight. A few tons of comet dust were deposited on Mars. A human sitting on the surface of Mars might have seen thousands of shootings stars per hour - a veritable meteor storm.

How the Sun works

At http://phys.org/print334398305.html ... we have an ultra violet image taken by the IRIS mission showing a network of solar jets. The journal Science has several articles on the IRIS discoveries - even though it only began in 2013. Intermittent small scale jets have been detected which appear to provide the energy behind the solar wind.

Apophis

At http://phys.org/print333876505.html ... in 2029, the asteroid Apophis is due to pass within 35,000km of the Earth - which is fairly close. What effect will it have? Well, a computer simulation by space scientists suggests that Earth's gravity will cause landslides - on the asteroid. The assumption behind the model is that gravity is the most potent thing to take into consideration. What if Apophis is accompanied by several smaller object in resonant orbit with the asteroid. How might it cope with Earth's magnetosphere?

Sand dunes on comet

 

This is an image from Comet Churyumov-Gerasimenko taken by the Rosetta spacecraft. Sent in by member Gary Gilligan it shows sand dunes on the surface of the comet - go to the link where you will see a succession of images, www.outerplaces.com/universe/technology/item/6469-stunning-results-image...

Magnetic fields and young stars

At http://phys.org/print333618940.html ... astronomers have found that the accretion discs around young stars also have a magnetic field which is described as a big surprise. This appears to indicate magnetic fields play a role in the formation of solar systems such our own one (Nature, 2014, DOI:10.1037/nature13850).

clouds above the Poles

At http://phys.org/print333394180.html ... astronomers are looking at strange clouds in the upper atmosphere of Titan, as seen by NASAs Cassini Mission - see also www.jpl.nasa.gov/news/news.php Oct 24th. These are described as methane ice clouds and they are situated above the Poles of Titan. The interesting thing is that the Earth  also has stratospheric clouds which are also above the Poles.

Unusual Comets

At www.scientificamerican.com/article/exocomets-around-beta-pictoris/ ... again, this is a piece of French observation and research beginning way back in 1986. The astronomer, Anne-Marie Legrange, and colleagues, witness something peculiar. Beta Pictoris seemed to be in the process of assembling its own planetary system. After months of trying to work out what was going on and what exactly they might have seen they came out with an odd explanation - for the time. They offered up what seemed to be an unlikely explanation.