Simulated galaxy composite / MSSL/UCL (background image NASA/HST)
ExoMars PanCam Field Trials / Andrew Griffiths/MSSL, UCL
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Aurora Borealis, Iceland, 2015 / Carlos Gauna
Introduction The Mullard Space Science Laboratory (MSSL), UCL’s Department of Space and Climate Physics, is the UK’s largest and most wide-ranging university space science group. We are based at Holmbury St Mary near Dorking in Surrey, and have around 175 people working on space science and engineering projects and research. In astrophysics, we study the extreme Universe, the life of galaxies and the nature of the Universe as a whole. In solar system science, we study our active Sun, solar wind & space weather, space plasmas, planetary science & imaging and climate extremes. Our scientific work is supported by excellent engineering staff and facilities, which allow us to lead and collaborate on missions from ESA (European Space Agency), NASA, Japan, Russia and China. Much of our work is through the UK and European Space Agencies. Our design offices, workshops, test and assembly facilities, environmental testing equipment and clean rooms allow the conception, build, test, calibration and delivery of space instrumentation to the highest international standard. Mullard Space Science Laboratory
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Artists’s impression of a Type Ia supernova / ESA/ATG medialab/C. Carreau
The extreme Universe Stars end their lives in extraordinary ways. Stars like the Sun end up as hot dense cores. Larger stars explode as supernovae, and their remnants are ultra-dense neutron stars. Even larger stars end their lives as black holes, after an immense cataclysm which generates gamma-rays detectable from the furthest reaches of the cosmos. MSSL investigates neutron stars and gamma-ray bursts using facilities in X-rays and the ultraviolet/optical – mostly instruments we’ve built for ESA’s XMM-Newton (X-ray Multi-Mirror Mission) and NASA’s Swift satellites. We are particularly interested in highly-magnetised neutron stars called magnetars, which emit spectacular outbursts of soft-gamma-rays, and in young hot neutron stars still cooling after their supernova. We use these objects to examine the physics of ultra-dense matter, and the extraordinary interaction of radiation and matter in the most extreme magnetic fields in the Universe. The novel technique of X-ray polarimetry is one of our current interests, as is the nature of the fireball resulting from the formation of the black hole, and whether there is a continuum of characteristics between supernovae and gamma-ray bursts. At the centres of at least most galaxies there are even larger black holes, millions of times more massive than those formed in stellar explosions. They lie at the focal point of the galaxy’s gravitational field, growing by taking in gas, stars, and stellar remnants. The strong gravity of these large but extremely dense objects shapes the space around them. The path that light takes is no longer straight, and as seen from a distant observer, the scene about them is distorted and multiplied. We calculate these effects, including absorption and scattering by intervening material in disks and clouds, to predict their signatures in our observations, and hence to arrive at the nature of the environments of black holes.
What happens to stars at the end of their lives? How does light travel near a black hole? What is the environment of black holes in active galaxies?
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The outline of our Galaxy, the Milky Way / ESA/Gaia
The life of galaxies The emission of energy from the region around black holes at the centre of galaxies disrupts the inflows from the external universe of gas which is the fuel for the next generations of stars. Supernova explosions and high velocity winds from young hot stars also drive out the interstellar gas from the galaxy, and these effects combine to choke off the formation of new stars. By examining the stellar populations, using, for example, spectroscopic surveys, and by fitting population models, we recreate the potential evolutionary paths of galaxies of different types and in different environments, to understand more about the general principles governing galaxy evolution. In particular we are interested in the relative importance of black holes and supernovae in this process. As much of the star formation occurs in dusty environments from previous generations of stars, this investigation requires data in the far infrared or submillimetre band where dust is most transparent, and for this we use instruments we’ve built for ESA’s Herschel satellite. Our own Milky Way is particularly important for understanding how galaxies evolve, because we can observe individual stars and their motions within it. By building dynamical and stellar evolution models in our computers, we can model in detail the mix of different generations of stars, and make predictions about the Milky Way’s structure. We compare these predictions with data from ESA’s Gaia satellite, and especially from the spectroscopy instrument in which we’ve had a significant role. This is how we explore the predicted observational signatures from spiral arms, to discover how these beautiful features are formed, and whether they are long-lived or transient.
What is the structure of our Milky Way? How do spiral arms form? What do stellar populations tell us about a galaxy’s past? How do black holes and star formation affect the way galaxies evolve?
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The nature of the Universe On the largest scales, we work to understand the properties of the Universe. After its origin in a Big Bang, the Universe has expanded and cooled. We can measure the temperature of leftover radiation to extraordinary levels of accuracy, for example using data from ESA’s Planck satellite, to understand the origin of the fundamental physics of matter, and how the initial structure of the Universe may have been imprinted from the quantum mechanics of subatomic particles. Because gravity is always attractive, the mutual attraction of matter in the Universe should lead to its expansion rate slowing, but measurements in the last two decades have shown that it is increasing. The amount of energy required to increase the expansion rate is enormous; it is most of the energy in the Universe. As we have no understanding of its nature, we call it Dark Energy. Also, after many years of ingenious investigations, we have found that most of the matter in the Universe appears to be unlike normal atoms and molecules, so we call this Dark Matter, and it causes increasing clumpiness in the Universe as it ages. Although this material isn’t as concentrated as in the regions around black holes, it bends the light travelling to us from distant galaxies; a process called weak gravitational lensing. These slight distortions provide powerful constraints on the clumpiness of the Dark Matter, and, as we look further away and back in time, on how the clumpiness has evolved. Because this clumpiness is affected by how much Dark Energy there is, we can study both Dark Energy and Dark Matter using weak gravitational lensing. We are building the camera for ESA’s Euclid satellite to make exquisite images of billions of distant galaxies, and developing the advanced mathematical and statistical techniques to extract the cosmological information from them.
Why is the expansion of the Universe accelerating? How can we use large surveys to measure the properties of the Universe?
Artist’s impression of Euclid / ESA/C. Carreau
Solar Xray Flare X 20, April 2, 2001 / ESA/NASA/SOHO
Our active Sun Our Sun is our nearest star and the only star we can study at close range. From Earth, we can detect visible light from the photosphere at about 6000 K and radio waves. Solar eclipses reveal the corona, the million-degree region which is the source of the solar wind. The material is hot enough to be a ‘plasma’ – the fourth state of matter beyond solid, liquid and gas. A million tonnes per second of solar wind escapes the Sun, carrying the solar magnetic field into the heliosphere. We study how the solar wind is produced and escapes, why the corona is hotter than the photosphere, and impulsive events on the Sun such as flares and coronal mass ejections (CMEs). One of the key processes is magnetic reconnection, where oppositely directed magnetic fields explosively join, unleashing accelerated particles, flares and CMEs. High in the Sun’s atmosphere, filaments of slightly cooler plasma may arch away from the Sun. In space, we study energetic radiation from active events, such as X-rays and far ultraviolet wavelengths. We work on magnetic topologies and their evolution and propagation, with a goal of forecasting solar wind conditions away from the Sun. Energetic radiation tells us about solar flares and CMEs. We study the active Sun using spacecraft such as Hinode, STEREO (Solar TErrestrial RElations Observatory) and SOHO (Solar & Heliospheric Observatory), and from 2018, Solar Orbiter . One key aspect is the north-south polarity of the emerging magnetic field, as well as shocks and variations in the solar wind. The polarity is critical to how damaging a solar event may be when it arrives at Earth. If there is a southward polarity, reconnection can be triggered upstream and downstream of Earth, allowing solar wind in.
What is the relationship between coronal mass ejections and the heliosphere, including the magnetic field polarity? What are the mechanisms for energetic proton release from solar flares, and the relation to sun- quakes?
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Solar wind, space weather and space plasmas Earth’s magnetic field gives some protection from solar and galactic cosmic rays and from the solar wind. Reconnection can allow particles into the magnetosphere, both upstream of the Earth and in the magnetic tail. Tail reconnection can shoot particles towards and away from Earth, in violent ‘substorms’. The Earth-directed particles follow the magnetic field and, in the polar region, collide with atmospheric particles to excite atoms and molecules, producing the aurora. The auroral regions couple the magnetosphere to Earth’s ionosphere. Some of the particles become accelerated and trapped, adding to the Earth’s radiation belts. We make in-situ measurements in the Earth’s magnetosphere to study key physical processes, including reconnection, acceleration, shocks and turbulence. We study particle acceleration in the aurora, initiation of substorms and radiation belt particle acceleration, using Cluster, THEMIS (Time History of Events and Macroscale Interactions during Substorms) and MMS (Magnetospheric MultiScale). We also study the link between events on the Sun and in the solar wind and we will explore the link more through Solar Orbiter . We play lead roles in the Extreme UV imager and the Solar Wind Analyser on the mission. We are also very active in applied research, working with water companies, airlines and insurance companies to examine how space weather affects our daily lives. Coronal mass ejections sometimes reach out in the direction of Earth / ESA/NASA - SOHO/LASCO/EIT
What are the mechanisms for particle acceleration in the aurora and the role of wave acceleration in the radiation belts? What is the nature and origin of solar wind strahl, and the effect of solar wind discontinuities on the heliosphere?
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Planetary science and imaging Plasma effects on solar system objects other than Earth depend on the object and its environment. Reconnection is important at magnetised objects, such as Mercury, Ganymede and the gas giant planets. But at unmagnetised objects, for example, Venus, Mars, Titan, Pluto and comets, the magnetic field drapes, and plasma can interact with any atmosphere or exosphere. This can lead to the loss of atmosphere over time at these objects.
What is the importance of ionospheric photoelectrons as a cause of plasma escape at Titan, Venus and Mars? What is the link between in-situ plasma and remote sensing measurements at comets, including solar wind speed? Was there or is there life on Mars?
The magnetic environment of Saturn / ESA/Cassini
We study ionospheres and their interaction with their environments using photoelectrons. We have discovered heavy negative ions in Titan’s atmosphere which is the source of Titan’s haze and eventually fall to Titan’s surface. This same process plays a role at Pluto and perhaps Triton. We also study Jupiter’s and Saturn’s magnetospheres. We use Cassini, Mars Express, Venus Express and Chandra for this work. From 2030, we will use JUICE (JUpiter ICy moons Explorer) to study Jupiter’s magnetosphere and its interaction with Ganymede, Europa and Callisto. For comets, we study the effect of activity on the solar wind interaction. We use Rosetta to study the changing interaction of comet 67P and we compare this with Giotto at comets Halley and Grigg-Skjellerup. We also use comets to infer solar wind conditions at different parts of the solar system, and we model cometary sodium tails. At Mars, the loss of atmosphere over 3.8 billion years has made it uninhabitable at the surface. We use orbital imagery to study changes on the surface and the role of water, and we use super-resolution to improve the results. We are also preparing to study the geology and atmospheric physics using the ExoMars rover. Our PanCam instrument has a powerful combination of 3D wide-angle cameras to identify minerals, water and dust, and a high resolution camera to add texture, for launch in 2018.
Earth from Space: A southern summer algal bloom / ESA/ENVISAT
Venus in the ultraviolet and the infrared / ESA/Venus Express
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Windstorm striking Porthleven, Cornwall, January 4, 1998 / Simon Burt
Climate extremes Weather and climate extremes - notably tropical storms, extra-tropical storms and precipitation extremes - cause disaster and loss worldwide each year. We examine the drivers of variability in these events, and we model and predict their occurrence. This work is underpinned by historical and real-time satellite data, climate reanalysis data, weather station data and our own modeling. We also study the influence of solar activity on cold winters. Our work includes a strong applied theme with product development and licensing to the insurance industry and links to humanitarian organisations. We have created innovative extreme weather services for global tropical storms and European extreme weather, and we are developing a 100-year UK wind gust database to underpin new UK windstorm products. MSSL has been at the forefront of space science since the beginning of the space age, and will celebrate 50 years at the Holmbury St Mary site in 2017. We are involved in many of the key missions for the future including JWST (James Webb Space Telescope), Euclid, Solar Orbiter, ExoMars, JUICE and SMILE (Solar Wind Magnetosphere Ionosphere Link Explorer). We lead and collaborate on proposals for future missions and instrumentation. Our engineering is second to none; for example, our Cluster PEACE (Plasma Electron And Current Experiment) instrument continues to work well on all four spacecraft of the ESA Cluster mission after more than 15 years in orbit. Our research also has strong impacts in other fields, such as space weather effects, crack detection in steel manufacture and hurricane forecasting and relief. We are at the leading edge of scientific research and technology and our goal is to understand our place in the Universe.
How do we improve our understanding of the drivers and predictability of the UK/European winter
climate and Atlantic hurricane activity? How do we use 100
years of data to develop innovative UK windstorm products for the insurance industry?
Hurricane Katrina, 2005 / NASA
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Specialist Precision Engineering
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• Component prototyping and short runs
• In-house CADCAM design system
4 ManorWay, OldWoking,Woking Surrey GU22 9 JX
Tel: 01483 767756 Fax: 01483 740548 Email: sales @bctengineering.co.uk
www.bctengineering.co.uk
Remote Visualization for Next Generation CAE Improve team performance by ensuring real-time collaboration
High security: transfer pictures, not data High performance: remote GPU access with low-speed and high-latency networks Consolidation: move graphics processing and data to the datacenter – not on desktop
www.transtec.co.uk/en/go/hpc
Contacts: Telephone: +44 (0)1483 204 100
General Contact: office@mssl.ucl.ac.uk Public Outreach: outreach@mssl.ucl.ac.uk Industrial Contracts: Richard Cole (r.cole@ucl.ac.uk) Systems Engineering and Technology Management: Michael Emes (m.emes@ucl.ac.uk) Internet: www.ucl.ac.uk/mssl Twitter: @MSSLSpaceLab
Back cover: UK snowbound from space, January 7, 2010 / NASA Cover image: Coronal hole, October 10, 2015 from Solar Dynamics Observatory / NASA/SDO
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