On December 17th, the European Space Agency’s CHEOPS telescope will blast into space to take a closer look at some of the potentially habitable planets we’ve found beyond our solar system. Ahead of its launch, Horizon takes an in-depth look at what we already know about such exoplanets and what’s still to learn. We speak to Dr Michaël Gillon, who in 2017 was instrumental in discovering a system of seven Earth-like planets outside our solar system, about the diversity of the thousands of exoplanets we’ve found so far and next steps for research. We talk to scientists who are trying to understand the structure of Super-Earths – planets up to 10 times the size of Earth – by recreating elements of planetary cores in their labs, and others who are trying to understand how different planetary systems formed in the first place. Finally, we delve into one of the most important conditions for life to exist on exoplanets – their atmospheres – and find out how scientists are trying detect the biosignature gases that indicate the presence of life.
It may be that life is lurking out there on other planets. But stuck here on Earth, how can we ever know for sure? A good place to start is by looking for the compounds on other worlds that are known to be the key ingredients of life as we know it.
Twenty-four years ago, Swiss astronomers Michel Mayor and Didier Queloz discovered the first planet orbiting a sun-like star outside our solar system – a milestone recognised by this year’s Nobel prize in physics. Today we know of thousands more ‘exoplanets’, and researchers are now trying to understand when and how they form.
Rocky planets larger than our own, so-called super-Earths, are surprisingly abundant in our Galaxy, and stand as the most likely planets to be habitable. Getting a better idea of their interior structures will help predict whether different planets are able to generate magnetic fields – thought to be conducive for life to survive.
From the first discoveries of planets beyond our solar system in the 1990s, we now know of thousands of alien worlds, some of which could even be habitable to life as we know it. Now we need to detect more of these exoplanets and study them in detail, says astronomer Dr Michaël Gillon from the University of Liège in Belgium, who was involved in one of the most important exoplanet discoveries to date.
In January, we examine how the cryosphere - ice sheets, glaciers, sea ice and other frozen parts of the planet - is changing and what this means for our planet. Earth’s cryosphere reflects the sun’s heat, regulating climate. But as the cryosphere melts, sea levels are rising and there are other impacts too – such as glacier collapse, which can generate massive avalanches. We speak to glacier expert Professor Andreas Kääb about the current state of the planet’s ice and snow and how better satellite measurements can help us understand the impacts of melting. We look at Earth’s so-called 'third pole’ of the Tibetan plateau and how ice melt will affect the millions who live in the mountains and those who depend on its run-off for water. We look at a project drilling in the Antarctic for what could be the world’s oldest ice (1.5 million years old) to see what it can reveal about climate history. And we speak to sea ice scientist Polona Itkin to get a glimpse into a day in her life aboard German icebreaker Polarstern, currently carrying out the largest Arctic expedition in history.
Seven years after scientists successfully managed to adapt a gene editing system used by bacteria into one that can be easily used in labs to edit human genes, we take a look at some of the emerging applications and ethical issues of CRISPR-Cas9. We talk to the head of the European Group on Ethics in Science and New Technologies about whether the simplicity and low cost of CRISPR means that there is potential for misuse and what should be done about this. We find out how scientists have used CRISPR to create cows lacking two sugars that trigger the human immune system, leading to hopes of longer-lasting heart valves for transplant patients and healthier red meat. And we speak to researchers who are using CRISPR to improve other gene editing technologies.
Sea ice researcher Dr Polona Itkin of UiT The Arctic University of Norway in Tromsø is currently aboard a research vessel spending one year trapped in Arctic sea ice to study climate change up close. On 20 January she spoke to Horizon from the ship, Polarstern, about working through the polar night, the shortcomings of satellite data and fending off polar bears.
Each year, more than a million wildebeest migrate across the grassy plains of the Serengeti National Park in Tanzania into Kenya’s Masai Mara National Reserve. But on the borders of these protected areas, human populations are increasing and wild ecosystems are struggling to survive in the face of development. Understanding these pressures is crucial for protecting people and wildlife, and to curb illegal activities such as poaching.
Sea ice researcher Dr Polona Itkin spoke to Horizon about life aboard a research vessel drifting in the Arctic.
Researchers aim for new ways to reduce tensions and poaching.