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Archive for the 'UCL Science Picture of the Week' Category

Marvellous maps

By Oli Usher, on 20 October 2014

Part of George Greenough’s 1819 geological map of England & Wales, showing modern-day Cumbria (then Cumberland and Westmoreland)

Part of George Greenough’s 1819 geological map of England & Wales, showing modern-day Cumbria (then Cumberland and Westmoreland)

This picture shows part of George Bellas Greenough’s 1819 geological map of England and Wales – the first to comprehensively map what lies beneath England’s countryside. This page shows the counties of Cumberland and Westmoreland (modern Cumbria).

Greenough was a pioneering geologist of the 19th century who left his collections to UCL when he died in 1855. (His name is commemorated in UCL’s Earth Sciences student society, the Greenough Society.)

Some of Greenough’s maps, along with other historic items from UCL’s Geology Collections, were publicly displayed on Friday as part of Earth Sciences week.

 

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Space Shuttle commander visits UCL Academy

By Oli Usher, on 13 October 2014

NASA Administrator Charlie Bolden (right) with UCL Academy principal Geraldine Davies (left)

NASA Administrator Charlie Bolden (right) with UCL Academy principal Geraldine Davies (left)

Last week saw Charlie Bolden – a former Space Shuttle pilot who now heads up NASA – visit UCL Academy. In this week’s Picture of the Week, he can be seen visiting the school’s facilities with the principal, Geraldine Davies.

UCL Academy is a non-denominational state school in Swiss Cottage, around two miles north of UCL’s central London campus. The school, which is sponsored by UCL, educates local children and charges no fees, and has extensive input into its teaching from UCL academics and students. It opened in 2012, and recently sent its first student to UCL – to study chemistry.

Bolden gave an inspirational talk to students, and was mobbed by students as he toured the school afterwards.

UCL space scientist Lucie Green, who arranged the visit (and is one of the school’s governors), said: “UCL has a long history of working with NASA that began shortly after its formation in 1958. Today, we have an extended family that includes the UCL Academy and it’s wonderful to see the Academy being the focus for an inspirational visit by Charles Bolden. This is a very positive example of the value-added that comes from having such a broad community where we can work together for the benefit of the students.”

The event is covered in a post on the UCL Events blog, which begins:

Charlie Bolden was born in the deep south of the US, during the days of segregation and institutionalised racism. Despite this inauspicious start in life, he went on to a high-flying military career, commanded the Space Shuttle, spent 28 days in orbit and, in 2009, was made head of NASA by President Obama. He is the first African American to hold the position…

Read the full post here.

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UCL’s first Nobel Prize

By Oli Usher, on 7 October 2014

William Ramsay's Nobel Prize

William Ramsay’s Nobel Prize certificate. Photo: public domain

This week is Nobel Prize week. Prof John O’Keefe (UCL Cell & Developmental Biology) has just been announced as the winner of the 2014 Physiology or Medicine Nobel Prize for his work on positioning systems in the brain.

He joins a long list of Nobel laureates affiliated to UCL.

The very first of these was Sir William Ramsay, who won the 1904 Nobel Prize in Chemistry. Ramsay is seen as one of the fathers of chemistry at UCL, and he is responsible for the discovery of the noble gases. He also supervised two students who also went on to win Nobel Prizes themselves: Jaroslav Heyrovský and Otto Hahn.

Ramsay’s Nobel Prize certificate, pictured above, is held in UCL’s collections, along with his medal and some of the apparatus he used to carry out his research.

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Mapping the Apollo landing sites

By Oli Usher, on 29 September 2014

Lunar Orbiter Photographic DataApollo 11, which touched down in the Sea of Tranquility on 20 July 1969 was the first manned landing on the Moon. But prior to the human spaceflight project, NASA explored the Moon with robotic probes. One key element of this endeavour was the Lunar Orbiter programme, which included five spacecraft that mapped almost the entire lunar surface in 1966 and 1967. This was in part in order to identify landing sites for Apollo, but the missions also had broader scientific goals.

Shortly before the first manned landing, NASA published a catalogue of all their data from the Lunar Orbiter programme, entitled Lunar Orbiter Photographic Data. This features maps of the entire Moon, with the locations, sizes and shapes of all Lunar Orbiter photos marked on them, along with extensive technical information.

Today, missions like this work entirely online, but in those pre-internet days, the data had to exist in hard copy.

A copy of this book exists in UCL’s planetary science archives, the NASA Regional Planetary Imaging Facility. Among its pages is the mapping of the area Apollo 11 landed in, the Sea of Tranquility (Mare Tranquilitas here). This is located towards the right of this sheet, where the imaging (marked in red) is densest.

Lunar Orbiter V - Sea of Tranquility

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The LHCb experiment

By Oli Usher, on 22 September 2014

The LHCb experiment. Credit: CERN (licence)

The LHCb experiment. Credit: CERN (licence)

This week’s Picture of the Week is the LHCb (Large Hadron Collider beauty) experiment at CERN. Located in a cavern on the the French side of the Circle Line-sized cross-border particle accelerator, LHCb is as big as a house. The detector investigates why our universe is dominated by matter, rather than antimatter.

Prof Nick Brook, the newly appointed Dean of Mathematical & Physical Sciences at UCL, was the computing project leader on the LHCb experiment during the vital period leading up to first data taking. He joins joins a wide range of other CERN researchers based here.

Jon Butterworth, UCL’s head of physics, will give a public talk about his role at CERN and the discovery of the Higgs Boson on 15 October. Click here for more information.

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This picture may be reproduced providing you follow the conditions of the CERN licence.

 

Rosetta landing site chosen

By Oli Usher, on 15 September 2014

Rosetta landing site

The landing site for Philae, the lander component of the Rosetta mission, has been chosen and is marked here with a white cross. Photo credit: ESA

The Rosetta mission, which for the past decade has been on a long and convoluted journey to Comet C-G, has recently reached its destination. It is the only artificial object ever to enter orbit around a comet, and is currently circling around it at an altitude of around 30km. (The cometary nucleus itself is around 4km across.)

Part of Rosetta’s mission is to measure the properties of the plasma (electrically charged gas) that surrounds the comet. To this end, the spacecraft features a suite of five sensors built by the Rosetta Plasma Consortium, a scientific collaboration that includes UCL’s Prof Andrew Coates.

But as well as measuring the plasma around the comet, Rosetta will attempt something never achieved before: it will release a lander that, later this year, will touch down on the comet’s surface. The European Space Agency has today announced the site that the lander, known as Philae, will aim for: a spot known as Site J, pinpointed in the photo above with a white cross. The landing site was chosen as the best compromise between safety (the surface of the comet is uneven in places and could damage the probe) and scientific interest (some parts are more active than others).

Copyright: ESA images are free to use providing they are credited, do not imply endorsement by ESA, do not feature identifiable individuals, and are not used in advertising or promotional materials.

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Close encounters with fear and dread

By Oli Usher, on 8 September 2014

Cover of Phobos: Close Encounter Imaging from the Viking Orbiters

Cover of Phobos: Close Encounter Imaging from the Viking Orbiters

This week’s Picture of the Week comes from UCL’s planetary science archives, and their rich collection of early NASA space images. Many of these are not available anywhere online, and some of them are hidden behind rather unpromising covers (see above).

The Viking missions to Mars, two identical spacecraft launched a few weeks apart in 1975, are well known for making the first successful landings on the surface of the red planet. But the Viking orbiters were important too, mapping the surface of the planet and observing its moons, Phobos (fear) and Deimos (dread).

This NASA book from 1984, entitled Phobos: Close Encounter Imaging from the Viking Orbiters is a comprehensive album of the observations the programme made of Phobos, the larger of the two moons.

This picture shows a typical spread, produced during the flyby of Phobos on May 26, 1977 by Voyager Orbiter 1.

Phobos from Viking 1

Phobos from Viking 1

Although it is the larger of the two moons of Mars, Phobos is still very small, and seems likely to be an asteroid captured by Mars’ gravity, rather than a moon formed at the same time as its parent planet.

A fraction of the size of Earth’s Moon, its gravity is not strong enough to have pulled it into a sphere, leaving the irregularly-shaped object visible here.

A Russian mission to land on Phobos and return a sample to Earth, Fobos-Grunt, malfunctioned shortly after launch in November 2011 and never left Earth orbit.

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Mapping the light of the cosmos

By Oli Usher, on 1 September 2014

This image shows one possible scenario for the distribution of light in the cosmos. Photo credit: Andrew Pontzen/Fabio Governato

This image shows one possible scenario for the distribution of light in the cosmos. Photo credit: Andrew Pontzen/Fabio Governato

Figuring out what the structure of the universe is surprisingly hard. Most of the matter that makes up the cosmos is totally dark, and much of what is left is in tiny, dim galaxies that are virtually impossible to detect.

This image shows a computer simulation of one possible scenario for the large-scale distribution of light sources in the universe. The details of how light (and hence galaxies and quasars) is distributed through the cosmos is still not a settled question – in particular, the relative contributions of (faint but numerous) galaxies and (bright but rare) quasars is unknown.

A faint dwarf galaxy

(New research from UCL cosmologists published last week shows how we should be able to find out soon.)

However, astronomers know that on the largest scales, the universe is structured as a vast web made up of filaments and clusters of galaxies, gas and dark matter separated by huge, dark voids. Observational astronomy is making strides forward in mapping out these structures in gas and light, but the smallest galaxies – less than a pixel across in the image above – might never be seen directly because they are simply too faint.

A Hubble image of a nearby faint dwarf galaxy (right) shows the challenge involved in observing these objects even when they are in our galaxy’s vicinity.

These computer models are one way of trying to extrapolate from what we know to what is really there. New research from UCL now shows how we can also use future observations of gas to find out more about this elusive population of tiny galaxies.

This simulated image shows the distribution of light in an area of space over 50 million light-years across. The simulation was created by Andrew Pontzen of UCL and Fabio Governato of the University of Washington.

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Photo album from the Dark Energy Survey

By Oli Usher, on 18 August 2014

The Dark Energy Survey, which has just begun its second year of observations, is gathering data about one of the most puzzling phenomena to be discovered in the past century: that the universe is not only expanding, but is doing so at an ever faster rate. Some as yet unknown force dubbed ‘dark energy’ is driving this acceleration.

Dark energy affects the appearance and evolution of the universe on very large scales. The Dark Energy Survey aims to find out more about this phenomenon by studying measuring four key cosmological probes:

  • The number of galaxy clusters;
  • The distances to faraway supernovae;
  • The bending of light by gravitational lensing;
  • and the pattern of the distribution of galaxy clusters across the universe.

Observing these requires sharp images that can detect very distant (and hence faint) objects, and so the the images collected by the Dark Energy Camera, the survey’s workhorse, are often quite stunning.

This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster, roughly 65 million light-years from Earth. It is 135,000 light-years in diameter, just slightly larger than our own Milky Way galaxy, and contains more than a billion stars. Credit: Dark Energy Survey.

This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster, roughly 65 million light-years from Earth. It is 135,000 light-years in diameter, just slightly larger than our own Milky Way galaxy, and contains more than a billion stars. Credit: Dark Energy Survey.

To mark the beginning of the second year of DES’s five-year observing run, the team have published a gallery of the most attractive images from the first year of operation, including the image of galaxy NGC 1398, pictured above. The complete the gallery is at the end of this post and in the faculty Flickr gallery.

UCL is deeply involved in DES, and Prof Ofer Lahav, Vice-Dean (Research) of Mathematical & Physical Sciences, is chair of the DES UK board and co-chair of the DES international science committee.

More information on UCL’s involvement in the DES science programme is available in an article on the UCL news pages.

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Copyright: Dark Energy Survey photos are free to use providing they are credited to the Dark Energy Survey. Any queries on reuse should be sent to Fermilab Visual Media Services at vismedsr@fnal.gov.

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Dawn of the neutrinos

By Oli Usher, on 11 August 2014

In Fermilab, just outside of Chicago, an intense beam of neutrinos leaves a particle accelerator. Less than one hundredth of a second later, the neutrinos reach Northern Minnesota, over 700 kilometres away. Here, scientists and engineers are developing a number of large experiments to help them understand the properties of neutrinos – currently an area of considerable uncertainty in the world of physics.

One of these is a device known as CHIPS-M, pictured here at dawn on 1 August, just before it was deployed underwater in the flooded Wentworth-W mine pit in the background.

The CHIPS-M detector at dawn, on the day it was deployed in the flooded mine pit in the background. Photo courtesy Jerry Meier (University of Minnesota)

The CHIPS-M detector at dawn, on the day it was deployed in the flooded mine pit in the background. Photo courtesy Jerry Meier (University of Minnesota)

(This pit belongs to Cliffs Natural Resources who have kindly granted access and the land where the detector and control-shed are sitting has been provided by PolyMet Mining.)

This neutrino detector may look large (it is a 3.5m x3.5m cylinder), but it is in reality a small-scale prototype for a device which will be many times larger. The team developing the instrument is led by Prof Jennifer Thomas (UCL Physics & Astronomy).

Neutrinos barely interact with normal matter. Even though we know vast numbers of them pass through the Earth thanks to their production in nuclear reactions in the Sun, detecting even a single neutrino is extremely challenging, and larger detectors improve the odds of seeing one by increasing the amount of matter in their path.

Neutrino detectors can work in a number of ways. CHIPS-M works through detecting Cerenkov radiation which is produced in the water inside it. Like all methods of detecting neutrinos, it is indirect.

CHIPS-M consists of a large bag storing 50 tonnes of water, equipped with highly sensitive detectors, like the ones used in the IceCube Experiment in Antarctica,  that can pick up the tiniest flashes of Cerenkov radiation. When a muon-neutrino enters water, very occasionally, it will interact with the water and produce  a charged muon. Sometimes the muon-neutrinos oscillate into electron neutrinos and they can produce a charged electron. Both of these charged particles, if they have enough energy,  move through the water faster than light can. The electromagnetic wake these particles leave behind them is visible as a brief flash which can be picked up by the detectors.

In order to minimise false-detections caused by cosmic rays, energetic particles that come from space, CHIPS-M is placed 60 metres deep at the bottom of a flooded mine pit: the water above it shields it from some of this interference as indeed does the orientation of the photo-detectors inside the bag.

 

The CHIPS-M detector being lowered into the mine pit and filled with water. In the boat is UCL physicist Prof Jennifer Thomas. Photo courtesy Jerry Meier (University of Minnesota)

The CHIPS-M detector being lowered into the mine pit and filled with water. In the boat is UCL physicist Prof Jennifer Thomas. Photo courtesy Jerry Meier (University of Minnesota)

And yet despite this shielding, over the year-long experiment, it is estimated that it will detect around 170,000 cosmic rays and just 20 neutrinos. Any positive identification of neutrinos in this period is in reality just icing on the cake, though – the primary objective of CHIPS-M is as a test-rig for technologies that will be used in future, for instruments far larger and more sensitive than this.

 

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