Astronomy news

Gravity and the earth ... and the Sun.

Some exciting science at www.bbc.co.uk/news/science-environment-12911806?print=true ... GOCE, the Gravity Field and Steady-State Ocean Circulation Explorer, is onboard a satellite launched in 2009 and moves around the earth from pole to pole at an altitude of 255km. It is able to map the very small differences in pull exerted by the mass of the planet from one region to the next - from mountains to ocean trenches. It can calculate gravity at any given point that it observes.

The Planet Mercury

NASAs Messenger spacecraft is now in orbit around Mercury and has returned the first image of the planet. Altogether some 360 + images have been taken by NASA and these will be released later in the week. See www.sciencenews.org/view/genric/id/71951/title/First_portrait_of_Mercury...

Einstein

At www.dailygalaxy.com/my_weblog/2011/03/could-space-time-be-a-mirage-new-t... there is a story about gravity and relativity and variations as advanced by Peter Herova that eliminates dark matter and dark energy by adjusting Einstein. In contrast, at www.physorg.com/print220174620.html where it claims Einstein's theory fights off challengers. 

Saturn

See www.jpl.nasa.gov/news/news.cfm?release=2011-0912cid=release_2011-091 and www.space.com/11205-saturn-strange-radio-signals-cassini.html for some perplexing signals from Saturn. The Cassini spacecraft has revealed a variaton in radio-waves as a result of the planet's rotation in its southern and northern hemisphere. They also change with the seasons (see www.nasa.gov/multimedia/videogallery/index.html?media_id=74390781 Apparently, Saturn is weird. Saturn emits radio waves - but unlike Jupiter. It may all be to do with the Sun's influence on Saturn.

Flying Saucers and the Rings of Saturn

This story is at www.dailygalaxy.com March 17th ... and concerns weird flying saucer shaped moons in the rings of Saturn that have intrigued astronomers after seeing them on images transmitted by the Cassini spacecraft. A paper in the December 6th issue of Science says the two Yorkshire Pudding shaped Aunt Bessie like moons seem to be formed from the same material as the rings themselves. They are in effect, clumps of ice and dusty accretions. The actual flying saucer shape is found elsewhere in the universe - around what are thought to be black holes, around stars, around Jupiter etc.

Apophis - the asteroid

At www.physorg.com/print219060207.html we learn that astronomers are keeping tabs on asteroid Apophis as it approaches a close encounter with the earth in 2029. The position of the asteroid over the next few months will enable astronomers to study it more closely - before its orbit takes it back into the Sun's glare. That makes observation virtually impossible.

X-Flares and Quakes

At http://spaceweather.com March 12th, it is said it is just a coincidence that the earthquake in Japan coincided with a geomagnetic storm - in case anyone was thinking otherwise. Earthquakes occur without geomagnetic activity and vice versa - but does that put paid to the possibility?

Enceladus (heat from the Poles) and ET life in a meteorite

At www.jpl.nasa.gov/news March 7th ... heat from the south polar region of Saturn's moon Enceladus has been found to be much greater than previously deduced. The new information is derived from the Cassini spacecraft and has been written up in a paper in the Journal of Geophysical Research (March 4th, 2011). At the south Pole there are a number of linear fissures which seem to indicate the heat is internal - but this is guesswork.

Sun Spots - mystery solved?

At www.physorg.com/print218294599.html (and see also http://wattsupwiththat.com March 3rd for the same story but with lots of comments). Scientists think they have solved how the Sun works - and have produced a computer model on its past performances. The real meat is yet to come - can they predict how the Sun will behave in the future?

The earth is being bombarded by space dust - but where does it come from?

The story is at www.physorg.com/print218218067.html and no doubt at the NASA web site too. NASA are saying that every day 100 tons of meteoroids - frangments of dust and gravel and sometimes small rocks enters the atmosphere of the earth - but it is unclear from what source. It is generally assumed the passage of comets leave behind trails of debris after they round the Sun.