Space


Just before totality on a total lunar eclipse. Credit: Flickr/John Johnson, CC BY-NC-SA

By Tanya Hill, Museum Victoria

At least twice a year, Earth comes between the sun and the moon. The result is a lunar eclipse, where we see the splendid sight of Earth’s shadow falling across the moon.



Astronomers have discovered an asteroid called 2014 OL339, that is the latest quasi-satellite of Earth – a space rock that orbits the sun but is close enough to Earth to look like a companion.

Our planet has one permanently bound satellite - the Moon, but also a likely large number of mini-moons or transient irregular natural satellites, and temporary natural retrograde satellites or quasi-satellites.
A team of researchers has proposed a solution to the problematic chemical composition of Neptune and Uranus, perhaps providing clues for understanding their formation.

Uranus and Neptune, which post-Pluto are considered the outermost planets in the Solar System by the International Astronomical Union, each have a mass approximately fifteen times that of the Earth and consist of up to 90% ice, with highly enriched in carbon. 

It's no surprise that water was crucial to the formation of life on Earth. What may surprise you is that water on earth is older than the sun itself.

Identifying the original source of Earth's water is key to understanding how life-fostering environments came into being and how likely they are to be found elsewhere. A new paper in Science says that much of our Solar System's water likely originated as ices that formed in interstellar space. Water is found throughout the Solar System, not just on Earth; on icy comets and moons, and in the shadowed basins of Mercury and in mineral samples from meteorites, the Moon, and Mars. 



Surprises in the dark. Credit: NASA GSFC, CC BY

By Rene Breton, University of Southampton

The nice thing about telescopes is that we can look back in time - light that is reaching us now may have originated a few hundred million years after the Big Bang, which means astronomers can view the universe as it was when it was much younger.

But sometimes we can be fooled by entire galaxies. DDO 68, otherwise known as UGC 5340, a ragged collection of stars and gas clouds, at first was thought to be a recently-formed galaxy in our own cosmic neighborhood.


But it's not as young as it looks. 


A cosmic oddity, dwarf galaxy DDO 68. Credit: NASA, ESA. Acknowledgement: A. Aloisi (Space Telescope Science Institute)