Piercing the Glare: Direct Imaging Exoplanets Quiz

If indirect methods like radial velocity infer a planet's existence from its effect on a star, and if direct imaging focuses on detecting light that originates from or reflects off the planet itself, then the goal is to capture photons from the planet.

If a star is typically millions to billions of times brighter than its orbiting planet, and if that overwhelming glare masks the planet's faint signal, then the high contrast ratio is a primary technical obstacle.

If the glare of a star prevents an observer from seeing a nearby planet, and if a specialized disk is placed in the telescope's light path to create an artificial eclipse, then that device is called a coronagraph.

If young planets are still hot from their formation, and if hot objects emit the majority of their thermal radiation at longer wavelengths, then the contrast between the star and the planet is lower in the infrared, making the planet easier to detect.

If a technique involves manipulating light to resolve a small, faint object next to a bright star, then adaptive optics, coronagraphs, starshades, and interferometry qualify, whereas radial velocity is an indirect method measuring motion.

If the angular separation between two objects decreases as they get closer together, and if a telescope has a limit on its resolving power, then a planet close to its star is much harder to distinguish from the star's glare than a planet in a wide orbit.

If a coronagraph blocks light inside the telescope, and if an external occulter is designed to block starlight before it even enters the telescope's aperture, then the starshade must be positioned thousands of kilometers in front of the telescope.

If a planet is newly formed, it retains significant heat from gravitational contraction; if it is massive, it has more surface area to radiate that heat; then it will be bright enough in the infrared to be "seen" by current imaging technology.

If the Earth's atmosphere distorts incoming starlight, and if ground-based instruments emit their own heat, then these factors create "noise" that obscures the faint signal of a planet, regardless of the moon's gravity.

If Earth's atmosphere causes light to blur (scintillation), and if a computer-controlled mirror can change its shape thousands of times per second to cancel out that blur, then the resulting image becomes sharp enough to resolve a nearby planet.

If direct imaging provides the exact position of a planet relative to its star at a specific moment, and if multiple images are taken over several years, then astronomers can track the planet's movement to map its orbital path.

If light acts as a wave, it will spread out when passing through an opening; if this spreading limits the ability to distinguish two close objects, then the limit of that resolution is known as the diffraction limit.

If a coronagraph or starshade is used to block starlight, it creates a "dark zone" around the star; if the edge of this zone represents the closest a planet can be to the star while still being visible, then that boundary is the Inner Working Angle.

If you can isolate the light of the planet, you can analyze its spectrum for chemicals and temperature; if you track its position over time, you can find its orbit; however, mass usually requires additional gravitational data.

If Earth-sized planets are very small and dim, and if current imaging technology is limited to finding large, hot planets far from their stars, then the transit and radial velocity methods remain far more successful for finding Earth-like worlds.

If astronomers successfully captured an image showing four massive planets orbiting the star HR 8799, and if this was one of the first multi-planet systems ever photographed, then it stands as a landmark for direct imaging.

If a star appears as a blurred blob (PSF) in an image, and if the planet is hidden inside that blob, then using software to model and subtract the star's specific light pattern (PSF) is necessary to reveal the planet.

If a telescope is equipped with a coronagraph and operates above the atmosphere, then it is capable of direct imaging; JWST, Hubble, and the upcoming Roman telescope fit this description, while Voyager is a deep-space probe.

If light behaves like a wave, and if you can combine waves from two different points so that the peaks of one meet the troughs of the other (destructive interference), then you can "null" or cancel the starlight while letting the planet's light pass through.

If JWST observes in the infrared and has a coronagraph, and if dust disks emit infrared radiation and surround young stars, then the telescope is perfectly suited to image the environments where "protoplanets" are being born.