Astronomy end of term round-up

Almudena Visser

Explores The Latest News Updates On Astrophysics

HERE are some exciting updates you may have missed.

Saturn’s rings discovered to be remarkably young: development, it was discovered last month from Hubble Telescope observations that icy particles from the rings are slowly raining down on Saturn’s atmosphere, meaning they could disappear altogether in another 100 million years, their lifetime a mere blink of an eye in cosmic terms. First observed by the astronomer Galileo Galilei in the 1600s, the origin of Saturn’s rings is not yet known, and remains the next puzzle for planetary astronomers.

While Saturn itself is thought to be around four billion years old, its famous rings are only a fraction of this age, having appeared only 400 million years ago, according to research published in the journal Science Advances by astronomers from the University of Colorado Boulder.

Fine rocky grains travel through our solar system constantly, settling as dust on planets and rings alike: Researchers studying data from the Cosmic Dust Analyser and Cassini space missions noted that while Saturn is coated in such dust, its rings are surprisingly clean and formed of 98 per cent pure water in ice form. From the lack of dust present in the rings, it was deduced that they must be much younger than the planet, having formed more recently. In another

Massive galaxies perplex astronomers: Zooming out somewhat to a larger scale, recent observations by the internationally funded James Webb Space Telescope have found unexpectedly massive galaxies that may have thrown a spanner in the works for current galactic formation models. The unrivalled sensitivity of this recently launched telescope has allowed astronomers to peer at a handful of galaxies so distant their light has been travelling for 13 billion years. This is almost as long as the Universe is thought to have been around (13.8 billion years), meaning these were some of the first ever sources of light.

Galaxies take considerable time to grow, which increases with size. Given their enormous luminosities and masses, it is unclear how these early universe galaxies, made up of millions of stars, managed to reach their huge sizes in a mere 800 million years, a short time in astronomical terms. According to current models, which predict slow galactic growth, young galaxies of this age should be 10 to 100 times smaller, yet somehow these ones are not. A flurry of theories have been proposed by astronomers, including that illusive ‘dark matter’, an as yet undetected and hypothetical type of matter that doesn’t interact with light, may be responsible for this conundrum. Broadly speaking, dark matter has been proposed as a type of matter formed of unknown particles that interact solely by gravity, rendering it invisible, providing extra mass to galaxies to stop them flinging themselves apart with their rapid rotations. It is thought to account for 85 per cent of the niverse’s mass. With increasingly sophisticated instruments being used to push the frontiers of astrophysics, it is the goal of many within the astrophysics community to solve this long standing mystery.