What is the weather like on exoplanets?

16 Oct 2017

Image: Jurik Peter/Shutterstock

Prof Giovanna Tinetti is on a mission to to find out more about the weather and chemistry of exoplanets. Claire O’Connell reports.

We all know about the weather here on Earth. From hurricanes making headlines to apps that let us find out if the sun is likely to shine in the coming days, we are pretty clued in.

But what about the weather on other planets, and particularly the ones that lie outside our solar system? Discovering more about the atmospheric goings-on of exoplanets is just one of the new frontiers that Prof Giovanna Tinetti from University College London (UCL) is aiming to delve into.

Zoom out to exoplanets 

The discovery in recent decades of thousands of extrasolar planets beyond the familiar ones in our celestial backyard has opened up the door to exciting new research. Tinetti, who is professor of astrophysics at UCL, is on a mission to find out about them in more detail. 

In her talk ‘Brave new worlds: The planets in our galaxy’, which is hosted by Dublin Institute for Advanced Studies and takes place in University College Dublin (UCD) this Thursday (19 October), she will start at home and zoom out.

“I will begin with an overview, starting with the Earth, the planet we know, then zoom out and describe the planets in our own solar system and in our own galaxy,” she said. “The rest of the talk will be about what we know about the nature of exoplanets, what they are made of, what kinds of observations we can make today about the weather on exoplanets and the observatories we are planning for the future.”

Tinetti, whose background is in theoretical physics, developed an interest in exoplanets when she was doing her PhD in Turin, and she ‘converted’ to an exoplanet scientist. 

Over the years, more and more exoplanets were discovered – most notably by the NASA Kepler mission, which has detected thousands of planets orbiting stars beyond our solar system – but the finer details were limited.

“When exoplanets are discovered, most of the time you have limited amounts of information, such as their mass, velocity and distance [from their star],” explained Tinetti. “We are interested in more details like their weather, chemistry, temperature.”


Prof Giovanna Tinetti. Image: Bex Coates

Twinkle, twinkle, little satellite

Gleaning clues at such a distance is no easy task, though Dublin City University scientist Dr Ernst de Mooij and colleagues recently made a direct observation of weather changes on the gas exoplanet HAT-P-7b.

“If we [look at] the planets in our own solar system, we know they are quite variable and atmospheric conditions can change through time,” said Tinetti. “With exoplanets, we are just starting to get some hints of this.”

Homing in on exoplanets, Tinetti is science lead on the UK Twinkle mission to build a commercial, low-cost satellite that can decode signals from hundreds of exoplanets and find out more about their atmospheres. “It will be an infrared eye in space.”

Prof Giovanna Tinetti will deliver her talk ‘Brave new worlds: The planets in our galaxy’ in UCD on Thursday 19 October at 6:30pm. The talk is free but places must be booked in advance.

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Dr Claire O’Connell is a scientist-turned-writer with a PhD in cell biology and a master’s in science communication