Twinkle is a small, low-cost mission that will use spectroscopy to decode the light from hundreds of extrasolar planets and solar system objects. Twinkle will be able to reveal, for the first time, the chemical composition, weather and history of a large population of worlds orbiting distant stars. The Twinkle satellite will be built in the UK and launched into a low-Earth orbit within 3 to 4 years, using a platform designed by Surrey Satellite Technology Ltd and instrumentation led by UCL.
Why do we need Twinkle?
The Earth is special to us – it’s our home. But is it really special as a planet?
Every star you can see in the night sky is likely to be orbited by planets. There are probably a hundred billion planets in our galaxy alone. Are Earth and the Solar System rare examples where all the conditions are just right to support life? Or are there trillions of worlds out there that have an environment that is habitable?
Right now, nobody knows the answers.
In only 25 years, we have discovered over 3700 “exoplanets” in distant solar systems, and spotted many thousand more objects that may turn out to be alien worlds. But for all except a handful, we know only three things: where they are, how big they are and how close they are to their sun.
What about the interesting things? What’s the weather like? How have they evolved? Do big planets tend to swallow up small planets? Are there gases in the atmospheres that are the tell-tale markers of life?
International space agencies are not planning a mission to answer these questions for at least a decade. However, we have the capability and expertise – today – to find the answers.
Twinkle is a small mission with a big ambition: to be the first spacecraft to reveal what alien worlds are really like.
Twinkle will be the first mission specifically designed with the unique capabilities required for characterising exoplanet atmospheres. Its capabilities can also carry out space-based spectroscopy of solar system objects. Spectroscopy of exoplanets’ atmospheres has been pioneered with the Hubble and Spitzer space telescopes, both now nearing the end of their missions.
Other current and planned exoplanet space missions (e.g. Kepler, TESS, CHEOPS, Gaia and PLATO) and ground-based facilities (e.g. HARPS or Super-WASP) are designed to find new planets, rather than characterise their atmospheres. Twinkle will fill a current gap in facilities suitable for this challenging area of science.
How Twinkle will work
Orbiting around the Earth, unimpeded by our atmosphere, the Twinkle satellite will study more than 100 exoplanets as they orbit distant stars.
Twinkle will analyse starlight filtered through the halo of atmosphere surrounding the planet as it passes in front of its star. Molecules absorb and emit specific wavelengths, embedding a unique pattern of lines within from the electromagnetic spectrum. Twinkle will pick out these characteristic spectral ‘fingerprints’ and deduce which gases are present.
A planet’s atmosphere can tell the story of its history and evolution: impacts, volcanic activity can significantly alter the gases that will be found, and whether features like clouds will form. On our planet, life has significantly altered the atmosphere through time; this is likely to happen on other planets too.
Gases present in a planet’s atmosphere hold clues to whether it formed in its current orbit or whether it has migrated due to collisions, tidal forces or the gravitational influence of other planets. The make-up, evolution, chemistry and physical processes driving an exoplanet’s atmosphere are strongly affected by the distance from its parent star.
Twinkle’s instrument will analyse light in the visible and near-infrared wavelengths (0.4 to 4.5 micrometers). This will allow Twinkle to detect a wide range of molecules, including water vapour, carbon dioxide, carbon monoxide, hydrogen sulphide and exotic metallic compounds. Twinkle will detect organic molecules such as methane, acetylene, ethylene and ethane. It will also be sensitive to precursors to amino acids (the building blocks of life) e.g. ammonia and hydrogen cyanide.
By measuring the visible light reflected by an exoplanet and the infrared heat that it emits, Twinkle will work out the planet’s energy balance, its temperature and whether clouds are present or absent in the atmosphere. For very large planets orbiting very bright stars, Twinkle will even be able to obtain two-dimensional maps of temperature and clouds. With repeated observations over the lifetime of the mission, this will tell us about climate and weather on those planets.
A New Model for Astronomy Missions
Building an astronomy mission currently takes a decade or more. It’s time to approach space science from a different perspective.
Twinkle is using tried-and-tested technology to pioneer a new era of low-cost commercial missions for astronomy research. Our vision is to use existing technology to do highly innovative science, creating missions at one tenth of standard costs.
Surrey Satellite Technology Ltd (SSTL) will construct the spacecraft using the SSTL-300 platform it has developed for high-resolution Earth imaging. Twinkle will use off-the-shelf components and will reuse existing software to maximise cost, effectiveness and reliability. The spacecraft will have a high level of autonomy to minimise operational costs.
The Twinkle satellite will carry unique instrumentation designed to analyse the atmospheres of exoplanets and give radical insights into worlds orbiting distant stars. Twinkle will be the first dedicated satellite to provide this type of data and our market studies show an intense demand from scientists worldwide working in this cutting-edge field of research.
Twinkle will be built to operate for a minimum of three years, with the possibility of an extended lifetime of five years or more.
Twinkle will deliver:
• The first spectral observations of at least a hundred exoplanets
• The first dataset optimised for characterising exoplanet atmospheres
• The first thermal maps of exoplanets and their cloud cover at multiple wavelengths in the optical and infrared
• Repeated observations of exoplanets to monitor changes in climate and atmospheric composition
• Opportunities for all countries to access space data
• An education programme to engage school students with cutting-edge research
Twinkle will demonstrate:
• That cutting-edge astrophysics mission can be done quickly and cheaply by using of off-the-shelf technology.
• A new model for developing an astronomy mission independently from government funding and for releasing data
• UK leadership in science and engineering
Impacts on science:
• Ground-breaking insights into how planetary systems form and evolve
• A revolution in our understanding of weather and climate on exoplanets, especially those orbiting very bright stars.
• Observations of other astronomical objects (e.g. planets, asteroids and moons in our Solar System, stars in our galaxy)
Impacts on industry:
• Closer collaborations between the research and industrial communities
• Potential for a steady stream of small astronomy missions that can provide ongoing business for UK SMEs
Impacts on society:
• Twinkle will widen participation in STEM through education activities
• Twinkle will engage new audiences with science through social media and outreach activities
Who is Behind the Twinkle Space Mission?
Twinkle is the first mission from Blue Skies Space Ltd, a company co-founded by Prof Giovanna Tinetti, Professor Jonathan Tennyson and Dr Marcell Tessenyi in 2014 with the aim of enabling cost-effective, quickly-delivered scientific instruments for users worldwide through a service-based model.
The science consortium is led by UCL and includes researchers from Cardiff University, University of East Anglia, University of Hertfordshire, Imperial College, Keele University, University of Leicester, University of Manchester, The Open University, Oxford University, Queen Mary University London, Royal Holloway and Royal Observatory Edinburgh.
The satellite will be constructed by Surrey Satellite Technology Ltd (SSTL). In just thirty years, SSTL has established itself as a world leader in small satellite development, operations and services. The company has designed, manufactured, integrated, tested and launched 47 satellites and has more than 200 hundred years on-orbit experience. Successful projects include the Disaster Monitoring Constellation. SSTL is supplying the instrumentation for 22 satellites that will form Europe’s Galileo navigation constellation.
The instrument consortium includes Cardiff University, Open University, Leonardo-Finmeccanica, Surrey Satellite Technology Ltd, STFC Rutherford Appleton Laboratory, STFC UK Astronomy Technology Centre, UCL Department of Physics and Astronomy, UCL Mullard Space Science Laboratory.
Further details can be found on our Team page.
Twinkle Mission Status
Twinkle completed its Payload Study in July 2016. It is currently undergoing its Mission Definition Phase to generate a master construction schedule. Construction of the satellite will begin in the spring of 2018 for a launch in late 2020.
Preliminary work and the instrument study are funded through a grant from the European Research Council and UK universities. Funding for the overall mission will come from a combination of public and private sources.