Astronomy news

Moon Dogs

The first full moon of 2018 is a supermoon. The extra brightness on January 1st and 2nd is expected to cause side effects - such as moon dogs. These are rainbow coloured splashes of light to the left and right of the moon created by the light bending actions of ice crystals in high cirrus clouds (see http://spaceweather.com 28th December 2017) ....

Christmas Aurorae

At http://spaceweather.com  24th December we have news of a sprawling coronal hole that has sent us a nice Christmas present - an auroral display. It is not however a major geomagnetic event - but a rather minor one. More interesting is the meteor shower emanating from the asteroid Phaethon, described by Space Weather as a rocky comet. Phaethon came within 10 million km of the Earth  and the Pue space telescope picked up the images below. The arrow is pointing at a large concavity or depression. It also seems it is a bigger object than thought - with a diameter of 6km.

NASA and the Sun

At www.sciencenews.org/article/sun-corona-outer-atmosphere-complex ... newly analysed images could help solve mysteries about solar wind and the superhot corona. The outer corona may appear smooth and calm but freshly analysed images from NASAs STEREO spacecraft show an unexpected texture. It is full of knots, whorls and blobs.

Uranus

Worlds in Collision is making a dramatic comeback. What with collisions on Earth creating the Moon, and variously theories regarding Venus and Jupiter we now have Uranus as part of solar system billiard balls - see www.space.com/39123-crash-that-tilted-uranus-made-moons.html ... the crash that tilted Uranus made its moons. Uranus is tilted on its side. A new study claims an impact bowled Uranus over, sideways, and may have created its moons in the process - solving two problems with a single theory. Uranus possesses 27 moons 18 of which orbit its equatorial zone.

Alien Probes

Some people, it would seem, are seriously looking at the possibility the Oumuamua asteroid may be an alien spacecraft. It has exhibited some peculiar features - not least its pencil slim shape and its high speed. See www.scientificamerican.com/article/alien-probe-or-galactic-driftwood-set... ... is it a piece of galactic driftwood passing through our solar system or could it be an alien space ship.

Kech Cosmic Re-ionization Mapper

At https://phys.org/print432547128.html ... on the 'things are getting interesting' cavalcade this one is worth looking at. The Keck Cosmic Web Imager (KCWI) has been operative since September (2017) and detects light in the blue spectrum, or pattern of the visible wavelength. KCWI has been quite successful to date. However, when the second part of the project takes off, the Kech Cosmic Re-ionisation Mapper, it will map emissions of hydrogen at 'very high red shifts' in order to understand the environments of the first stars that formed.

Gravity Speed of Light

Jovan has sent in a lot of links this week. Here are two of them. At http://blogs.discovermagazine.com/d-brief/2017/12/08/speed-of-gravity-li... .... why does gravity travel at the speed of light. This idea is derived from the recent gravitational waves generated from a collision of two stars, 130 million years of age - in a far away galaxy. They reached the Earth in August 2017. These were neutron stars and the collision caused a gravitational wave - but gravity appears to have traveled at the same speed as light emitted from the same collision.

Fault on Mars

Robert sent in a number of links on the same subject - geology on Mars. More specifically, a so called fault line. See for example www.dailymail.co.uk/sciencetech/article-5177241/Glitches-matrix-NASA-rev... ... NASA reveals a stunning image from Mars. Robert asks, but is it all what it seems, a fault line.

Why iron meteorites make landfall but chondrites explode

Why iron meteorites reach the surface of the Earth but chondrites and conglomerate meteors tend to explode in the atmosphere - breaking into many pieces and leaving small scatters on the surface. It's all to do with air penetrating cavities in rocky meteorites causing them to weaken and explode apart. In other words, our atmosphere naturally protects the surface from the hazard of real meteorites - but there are always exceptions to the rule. Large chondrites have the ability to penetrate much closer to the surface - or even reach the surface.

Red Spot

Jovan sent in the links below - www.missionjuno.swri.edu/news/juno-probes-depths-of-great-red-spot ... and www.space.com/39066-jupiter-great-red-spot-depth-juno-spacecraft.html ... data collected by NASAs Juno spacecraft indicates that the great red spot penetrates deep below the upper atmosphere of Jupiter. The red spot is a giant oval of crimson coloured clouds that race counter clockwise around the perimeter of the anomaly ....