Wednesday, 3 January 2018

THE FIRST KNOWN INTERSTELLAR ASTEROID


This oddly elongated visitor to the Solar System was discovered on 19 October 2017 by Rob Weryk and Marco Micheli at the Institute for Astronomy in Honolulu, Hawaii, using observations from the Very Large telescope in Chile.


The asteroid's name 'Oumuamua' means 'a messenger from afar arriving first'.


http://www.bbc.co.uk/news/science-environment-42053634


The asteroid's speed and trajectory indicate it may have originated in a planetary system around another star. Oumuamua's observed properties suggest that it is a dense object, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over long periods of time. It could have been wandering through the Milky Way, unattached to any star system for hundreds of millions of years before reaching our Solar System.


Searches across four different radio frequency bands for anything that might resemble a signal resulting from alien technology have so far drawn a blank.


Professor Alan Fitzsimmons of Queen's University Belfast and colleagues have carried out measurements suggesting Oumuamua may have an insulating, carbon-rich layer on the outside, due to long exposure to cosmic rays, that could have shielded an icy interior from its encounter with the Sun.


http://www.bbc.co.uk/news/science-environment-42397398



Wednesday, 18 May 2016

Ivinghoe Beacon & Aylesbury Vale, from Whipsnade Downs, Bedfordshire.

A pleasant walk last Sunday over the chalk grasslands of Whipsnade Downs, searching for Duke of Burgundy butterflies, a rapidly declining species in the UK. Pleased to find more than twenty specimens. Also spotted Green Hairstreak, Red Admiral and Dingy Skipper butterflies.

Wednesday, 11 May 2016

BLUEBELLS IN HAY WOOD ON STOPSLEY COMMON, LUTON

A fine display of bluebells last Sunday morning, on a hot and sunny May day, in this small and relatively unknown but picturesque wood in Luton.

Friday, 1 May 2015

FOR MAY DAY



An excerpt from The Shepherd's Calendar, May.
John Clare Poet (1793 - 1864)

...
Come queen of months in company
Wi all thy merry minstrelsy
The restless cuckoo absent long
And twittering swallows chimney song
And hedge row crickets notes that run
From every bank that fronts the sun
And swathy bees about the grass
That stops wi every bloom they pass
And every minute every hour
Keep teazing weeds that wear a flower
And toil and childhoods humming joys
For there is music in the noise



John Clare – The Shepherd’s Calendar (May - excerpt)
(With thanks to Roger Arborfield)

Thursday, 30 April 2015

25 YEARS OF THE HUBBLE SPACE TELESCOPE

The Hubble Space Telescope has completed 25 years of astronomical observation since its launch on 24 April 1990.
http://www.bbc.co.uk/news/science-environment-32433839

Nasa Administrator Charlie Bolden said 'A quarter of a century later, Hubble has fundamentally changed our understanding of our Universe and our place in it'.

An early problem was a flaw found in the telescope's primary mirror that blurred its images A smart fix was installed by spacewalking astronauts in 1993 that allowed its instruments to correct for the aberration in the reflecting surface.

Engineers expect the observatory to keep operating for at least another five years. Its successor , the much bigger James Webb Space Telescope, is due for launch in 2018.

The scientific contribution of Hubble is enormous. Before Hubble, astronomers did not know whether the Universe was 10 billion or 20 billion years old. Hubble's study of pulsating stars narrowed the uncertainty. The age of the Universe is now known to be 13.8 billion years. Hubble also played a part in revealing the expansion of the Universe, and provided definitive evidence for the existence of super-massive black holes at the centre of galaxies, among many other discoveries.

Comment: The images received from Hubble have been truly breathtaking, and often stunningly beautiful. Hubble in many ways has revolutionised astronomy and cosmology.

Tuesday, 31 March 2015

DARK MATTER AND GALACTIC COLLISIONS

New observations on collisions of clusters of remote galaxies have shed further light on the nature of dark matter, enabling some theories to be ruled out.
http://www.bbc.co.uk/news/science-environment-32066013

Astrophysicists studied 72 collisions between galactic clusters. Visible light was recorded by the Hubble Space Telescope, and x-rays by the Chandra Observatory. The researchers tracked the movement of the three main components of galaxies: stars, clouds of gas, and dark matter.

Although dark matter, which makes up 85% of the matter in the universe, does not emit or absorb light, it does have gravity and its presence can be detected by its bending effect on light passing nearby.

Dr Richard Massey of Durham University and colleagues were able to map the dark matter during the galactic collisions. Unlike the gas clouds which interact strongly, and stars which glide past, the dark matter passes through everything and emerges unscathed.

The strongest result from the study was further evidence that dark matter really is present in the galactic clusters. Further, many theories of dark matter can now be ruled out, for example that dark matter is a  'dark version' of ordinary matter, made of 'dark atoms'.

Comment:  Dark matter and energy are slowly yielding their mysteries to these astrophysical observations. It's difficult not to feel that one day there will be a major breakthrough in our understanding.

Tuesday, 24 February 2015

REMEMBERING FUKUSHIMA NUCLEAR DISASTER 

There are several events in London next month marking the fourth anniversary of the Fukushima nuclear disaster, and opposing nuclear power. August this year will see the seventieth anniversary of the nuclear destruction of Hiroshima and Nagasaki.   I'm speaking at SOAS University of London on Tuesday 3 March, and also at the rally in Parliament Square at 2.30 pm on Saturday 14 March.