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

PanCam taking shape

By Oli Usher, on 8 December 2014

UCL’s contribution to the ExoMars Rover – the European Mars mission scheduled for touchdown in 2019 – is gradually taking shape. Quite literally.

The ExoMars PanCam optical bench being milled. Photo: MSSL

The ExoMars PanCam optical bench being milled. Photo: MSSL

This photo shows a prototype of the main structure of the panoramic camera (PanCam) instrument being machined out of a block of metal. PanCam will be the rover’s primary camera, producing high resolution 3D images of the Martian surface, and it is being being built by scientists and engineers at UCL’s Mullard Space Science Laboratory.

The ExoMars PanCam optical bench. Photo: MSSL

The Finished product. Photo: MSSL

The structure is known as the ‘optical bench’. All the precision-built optical components, including detectors, lenses, mirrors and filter wheels (below), will be attached to this rigid housing.

Filter wheels for ExoMars PanCam. Photo: MSSL

Filter wheels for ExoMars PanCam. Photo: MSSL

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Nanodrills in action

By Oli Usher, on 2 December 2014

A team of scientists at UCL and partner institutions has today published a study showing how certain harmful bacteria use tiny ‘nanodrills’ to make holes in our cell membranes.

These rings of toxin molecules assemble themselves on the cell membrane, then slice down, punching a hole and spitting out the piece of membrane they cut away. The rings then hold the hole open, much like an eyelet.

Nanodrills in action

Nanodrills in action. Credit: eLife/Bart Hoogenboom/UCL

This image is a still from a ‘video’ produced by an atomic force microscope (AFM) in Bart Hoogenboom’s lab at UCL. AFMs feel a surface rather than seeing it – a tiny needle is repeatedly moved across the surface and feels the shape and hardness of the sample: lighter colours represent raised surfaces.

In the full video (below), we see the ring-like structures skating over the surface of the membrane, before they start perforating the membrane.

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Peeling an egg

By Oli Usher, on 24 November 2014

Peeling a frog's egg

Peeling a frog’s egg. Credit: Armin Kramer

This sequence of images shows the painstaking act of peeling a frog’s egg. The egg is gripped with tweezers, carefully torn open, and the cell nucleus inside is separated out. The nucleus is the small, pale blob in the centre of the final frame, and it is well under a millimetre across.

This difficult procedure is a key element in new research published by UCL scientists today. In the study, scientists probed the membrane that surrounds the cell nucleus in order to determine the structure of tiny pores that play a key role in cell biology.

A full summary of their research, including a remarkable image of these pores, produced using an atomic force microscope, is available from UCL News.

You can also watch a video of the process below.

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Fossil crab

By Oli Usher, on 17 November 2014

Fossilised crab. Credit: UCL Geology Collections

Fossilised crab. Credit: UCL Geology Collections

This specimen, from UCL’s Geology Collections, shows a well-preserved fossilised crab. Its legs are largely intact and even the texture of its abdomen can be made out. The claws, however, are missing.

Crabs’ claws are one way to tell male and female specimens apart (males’ claws are generally larger). Interestingly, the shape of a crab’s underside also hints at its sex in most species.

(Any amateur or expert determinations of this crab’s sex are most welcome in the comments below.)

Crabs have existed since the Jurassic period, 145-200 million years ago.

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Countdown to touchdown

By Oli Usher, on 10 November 2014

Comet C-G, seen by Rosetta’s NAVCAM on 6 November 2014. Philae’s landing site is towards the top of the image. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

After a decade of travelling around the Solar System, the Rosetta probe is now at its destination: Comet 67-P/Churyumov-Gerasimenko (or Comet C-G to its friends).

The Rosetta mission is made up of two parts which have spent the last decade bolted together: the orbiter, and the lander, known as Philae.

Just after 9am GMT on Wednesday, Philae will separate from the mother ship and begin its descent to the comet’s surface. Around seven hours later, if all goes well, it will touch down on C-G’s rough surface.

This will be the first ever landing on a comet.

The gravitational force between two objects is directly proportional to their masses and the distance between them. Philae, at around 100kg, weighs much the same as a (large) human being, but the comet has a tiny fraction of the Earth’s mass. The pull between them is therefore minuscule – of the order of the gravitational force experienced by an object weighing just one gram on Earth.

Even though Philae will only be approaching Comet C-G at walking pace, the low gravity means it will need to attach itself to the surface with a harpoon to avoid bouncing back into space.

Because of this, the manoeuvre has been compared to a ‘docking’ rather than a ‘landing’.

UCL’s Prof Andrew Coates is a member of the Rosetta Plasma Consortium, which will be monitoring the plasma environment of the comet during Philae’s descent and landing. (He was also closely involved with the design and construction of Rosetta’s scientific payload.) He will be at mission control in Darmstadt on Wednesday as the lander begins its descent.

“The Rosetta orbiter and lander provide unique perspectives on how comets interact with the solar wind and on charged dust from the surface. The historic landing attempt will be a huge opportunity for coordinated observations,” says Prof Coates.

Comet seen over Rosetta's solar array, 14 October 2014. Credit: ESA/Rosetta/Philae/CIVA

Comet seen over Rosetta’s solar array, 14 October 2014, when the comet was around 16km away. Credit: ESA/Rosetta/Philae/CIVA (All rights reserved)

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The Hubble Space Telescope’s successor: UCL’s contribution

By Oli Usher, on 3 November 2014

JWST NIRSpec calibration assembly. Photo credit: UCL MSSL

JWST NIRSpec calibration assembly. Photo credit: UCL MSSL

The James Webb Space Telescope (JWST), currently under construction by NASA and ESA, will be the successor to the wildly successful Hubble Space Telescope. Unlike Hubble, which specialises primarily in observing the same light our eyes see (with limited ultraviolet and infrared capabilities), JWST is specially designed to observe in the infrared.

These wavelengths are interesting to scientists as they allow them to peer through thick dust clouds which scatter visible light, revealing areas of star birth and planetary systems forming. They also reveal the distant past of the cosmos, which has been redshifted out of the visible spectrum thanks to its extreme distance. Infrared observations are extremely challenging to do from the ground as most wavelengths of infrared are absorbed by the atmosphere.

(Hubble’s capabilities in visible light will be largely replaced by a new generation of ground-based observatories, such as the European Extremely Large Telescope.)

A vast project like JWST involves numerous institutions around the world – and among their number is UCL. UCL’s Mullard Space Science Laboratory is providing part of the NIRSpec (Near Infra-Red Spectrograph) instrument, which in turn is part of the European contribution to the telescope project. JWST will also be launched from a European Ariane rocket in 2018.

NIRSpec will break down the light into its component wavelengths, allowing for precise measurements of the motion and chemical makeup of stars and galaxies.

The Calibration Assembly, pictured here, built by UCL, ensures accurate observations by periodically testing the accuracy of the instrument’s colour measurements.

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Simplifying complex data

By Oli Usher, on 27 October 2014

One challenge in science is how to represent vast datasets in a way that the human eye and brain can understand. UCL statisticians Sofia Olhede and Patrick Wolfe have worked on methods of simplifying data on relationships between things in a way which captures all the important features, but is not so unwieldy that the patterns are lost.

blogs contour

The top pair of images on this page show data on how frequently blogs supporting different parties link to each other – showing frequent linking between fellow US Republican Party blogs and US Democratic Party blogs (top and bottom quadrants of the picture) but very little crossing the political divide (left and right quadrants). Peaks (in red and yellow) show groups of blogs that link to each other frequently, blue areas show combinations of blogs that rarely never link to each other. The lower image is a 2D map of exactly the same data.

The next image shows a mathematical approximation of the shape of the distribution of linking in that data – showing how the underlying pattern of blogs linking to each other is actually rather simple.

blogs idealized

 

A detailed article on the science behind these images – and what they tell us – will be published here on the UCL Science blog on Wednesday.

Picture credits: Patrick Wolfe, Sofia Olhede (UCL Statistical Science).

Data from Adamic and Glance

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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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