- How did Johannes Stark demonstrate the Doppler shift in fast-moving canal rays in the laboratory?
Exoplanets
Planets orbiting stars beyond the Sun.
- How did Aleksander Wolszczan detect planets orbiting a pulsar using radio pulse timing?
- How did Mayor and Queloz detect a planet they could not see directly around 51 Pegasi?
- Why did a gas giant orbiting so close to its star contradict existing models of planet formation?
- What is a 'hot Jupiter,' and how does migration explain its unusual orbit?
- How did astronomers detect sodium in the atmosphere of HD 209458 b using the Hubble Space Telescope?
- What is transmission spectroscopy and how does it reveal the chemical makeup of a distant planet's atmosphere?
- What other molecules have since been identified in exoplanet atmospheres using the technique pioneered on HD 209458 b?
- How had astronomers detected exoplanets before 2008 if none of them had actually been seen?
- How did the Marois team use adaptive optics to directly image three planets orbiting HR 8799?
- What technique did the Kalas team use with the Hubble Space Telescope to image a planet around Fomalhaut?
- How did Kepler's transit method detect planets by watching for tiny periodic dimming in starlight?
- How many exoplanets did Kepler confirm over its mission, and what did that reveal about how common planets are?
- How does the Kepler space telescope detect exoplanets using the transit method?
- What made Kepler-16b unusual compared to other confirmed exoplanets?
- Why were Kepler-20e and Kepler-20f significant despite being too hot for liquid water?
- Why is Proxima Centauri b considered to be within its star's habitable zone despite orbiting so closely?
- What does it mean for the planet to be tidally locked, and how does that affect its potential habitability?
- Why do Proxima Centauri's ultraviolet flares pose a challenge to any atmosphere the planet might have?
- What makes TRAPPIST-1 an unusual host star for a planetary system, given how dim and small it is?
- How many of the seven TRAPPIST-1 planets lie within the habitable zone, and what does that mean for liquid water?
- Why is TRAPPIST-1's proximity to Earth important for studying its planets' atmospheres?
- What open question about TRAPPIST-1's planets is the James Webb Space Telescope now investigating?
- How did Michel Mayor and Didier Queloz detect a planet around 51 Pegasi without ever seeing it directly?
- Why did the discovery of a hot Jupiter around 51 Pegasi force astronomers to revise theories of planet formation?
- Why did the 2019 physics prize combine a theoretical cosmologist with two observational planet-hunters in one award?
- How did JWST's Near Infrared Spectrograph detect carbon dioxide in the atmosphere of WASP-39 b?
- Why did this detection matter more for what it proved about Webb's capabilities than about WASP-39 b itself?