And… it’s literally six seconds of pixelated blob. But before you laugh, know this: Capturing that planetary transit you just witnessed was no easy task.
You’re looking at Beta Pictoris b, a gas giant 10 to 12 times the mass of Jupiter that orbits a star over 60 light years away. That’s 5.67631704 x 1014 kilometres from us and we’re actually able to see it! If you’re still not impressed, try this on for size: Beta Pictoris b is roughly a million times dimmer than its parent star.
From our perspective, Beta Pictoris b should be completely swallowed by starlight, and yet, we’re able to see it thanks to the incredible optical engineering that’s gone into the Gemini Planet Imager (GPI) instrument on the Gemini South telescope in Chile. First, GPI’s adaptive optics system sharpens the image of the target star by cancelling out distortion caused by Earth’s atmosphere. Next, it uses a filter called a coronagraph to block out all that pesky starlight, revealing the faint glow of orbiting planets.
Even with the most advanced optical systems in the world, astronomers have only imaged a handful of exoplanets directly, all of them Jupiter-plus-sized gas giants. We’ve ID’d another 2,000-odd planets via the indirect transit method, which entails measuring a faint dip in a star’s light output as a planet crosses its path.
But with forthcoming observatories like the James Webb Space Telescope, we’ll be able to peer deeper into space, block out more starlight and image worlds that were unimaginable a generation ago. There could be billions of planets waiting out there, and we’re building the tools to find them.