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

Darkness falls across the land

By Dewi W Lewis, on 24 March 2015

 

eclipse

These two photographs were taken in the quad during the eclipse. The first at 9:25 the second at 9:31am.

During this time the light dropped by a factor of 16: dropping from an Exposure Value (EV) value of 11 to 7, or 4 stops, to the photographers amongst you.

My eyes told me it got “a bit darker”, the reality was far more!

Hydrophobic art

By Oli Usher, on 5 March 2015

paint

Yau Lu (UCL Chemistry) is the lead author of some research which hit the headlines last week. His team has succeeded in making a water-resistant and self-cleaning coating which is both highly effective and very strong. Previous coatings have been weak, and easily scratched or flaked off.

Here, he shows how the hydrophobic  paint can be used to create a water-repellent design on glass. The hydrophobic coating, water and dye all come together to create an ephemeral artwork:

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Where noble gases won UCL a Nobel Prize

By Oli Usher, on 2 March 2015

IMG_0073-cc

Readers familiar with UCL will immediately recognise the Slade School of Fine Art – the North Wing on UCL’s historic (and grade I listed) quadrangle. What they may not know is that the building, which dates back to the 1870s, was originally also home to UCL’s Department of Chemistry.

It was in this building that some of UCL’s most famous contributions to chemistry were made: William Ramsay and his successor J Norman Collie both worked here.

In fact, as far as we can work out, it is the building in the world which has seen the discovery of the greatest number of chemical elements. Ramsay discovered argon, neon, krypton and xenon while working here, as well as isolating helium (which had been seen in the spectrum of the Sun, but not observed here on Earth) and radon. These elements are together known as the noble gases, and Ramsay’s discoveries secured for him the 1904 Nobel Prize in Chemistry – UCL’s first.

In 1913, the year of Ramsay’s retirement, UCL’s Chemistry department moved to a new purpose-built lab immediately behind its old home. The building – which still houses some of the department’s laboratories and offices – is now named after another towering figure in chemistry: Kathleen Lonsdale.

After a century of heavy use and piecemeal remodelling, the building is looking a little tired . A multi-million pound complete refurbishment of the building is planned to begin later this year.

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Twinkle: a new mission to study distant planets

By Oli Usher, on 9 February 2015

Twinkle. Credit: SSTL/Twinkle/DSS

A new satellite for observing extrasolar planets could be in orbit within four years, under plans drawn up by UCL and Surrey Satellite Technology Limited (SSTL). The Twinkle satellite, pictured above, will observe the light of distant stars with planets orbiting them.

As a planet passes between the star and Twinkle’s telescope, a small amount of the light passes through its atmosphere, imprinting on it the chemical signature of its atmosphere. This technique has been used by Hubble to analyse the atmospheres of a handful of exoplanets, but the Twinkle team hopes to probe at least 100 during the spacecraft’s mission.

UCL leads a consortium of UK institutes who will construct Twinkle’s scientific instrumentation, a highly precise infrared spectrometer which can tease out the faint signature of the planetary atmospheres from the starlight.

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Asteroid’s close encounter with Earth – the UCL view

By Oli Usher, on 2 February 2015

2004 BL86

Last week, asteroid 2004 BL86 passed near Earth. The ball of rock, a little over 300 metres across, passed 3.1 lunar distances from Earth.

This is far enough not to be of any serious concern – but it is closer than any other known asteroid will come to us until 2027. If an asteroid like 2004 BL86 were to hit Earth, we could expect widespread destruction – the famous Barringer Crater in Arizona was gouged out by an object just 50 metres across.

During its close approach, UCL’s observatory spotted the asteroid and snapped the picture above: a series of 30 second exposures separated by 9 second gaps. The asteroid can be seen moving rapidly against the background stars as the telescope was programmed to track the movement of the stars.

Reprogramming the telescope to hold the asteroid in its sights creates the image below – with the stars appearing as streaks instead.

2004 BL86

This video, featuring a series of observations of the asteroid made at the observatory over the night of 26-27 January, shows both types of observation, including a long shot tracking the asteroid across the sky.

Images by Steve Fossey, Theo Schlichter and Ian Howarth.

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A molecule-sized magnetic sensor

By Oli Usher, on 26 January 2015

STM image of iron phtalocyanine. Credit: Ben Warner, Fadi El Hallak and Cyrus Hirjibehedin (LCN)

STM image of iron phtalocyanine. Credit: Ben Warner, Fadi El Hallak and Cyrus Hirjibehedin (LCN)

This image shows a scanning tunnelling microscope (STM) image of a molecule of iron phtalocyanine, separated from an underlying layer of copper by a thin barrier of copper nitride.

The image is part of a new piece of research just published by UCL scientists. The iron phtalocyanine molecule forms part of a tiny magnetic sensor which is sufficiently sensitive that it can detect molecule-sized magnetic fields. This technology could allow far smaller hard disks and new computer memory designs.

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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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