Spikes in the Data: Detecting Small Exoplanets Quiz

If the transit depth is proportional to the square of the planet's radius divided by the star's radius, then a smaller planet creates a shallower dip; if the dip is very shallow, it is harder to distinguish from the background noise of the star.

If an Earth-sized planet has a radius roughly 1/100th that of the Sun, then its cross-sectional area is (1/100)^2, which equals 1/10,000; therefore, the telescope must sense a 0.01% drop in light.

If a data point represents a real physical event like a transit, and if random variations are present, then the clarity of the "blip" is determined by the ratio of the signal strength to the noise level.

If small planets produce very shallow transits, and if stars have natural variations like sunspots or pulsations, then the tiny planet signals will often be "buried" within these larger stellar noise patterns.

If sensitivity depends on precision, then collecting more light (mirror size/photons) and reducing electronic or mechanical interference (pointing/sensor heat) will increase the ability to detect tiny brightness dips.

If a transit signal is too weak to see in a single event, and if the orbit is periodic, then stacking and averaging multiple recorded orbits (phase folding) will cause the true signal to add up while random noise cancels out.

If the transit depth is determined by the ratio (Rp/Rs)^2, and if the star's radius (Rs) is very large, then the fraction of light blocked by a small planet becomes even smaller; therefore, large stars make detecting small planets harder.

If an Earth-sized planet blocks 0.01% of a Sun-like star's light, and if 0.01% is equivalent to 100 out of 1,000,000, then the standard scientific unit for this precision is parts per million.

If a star's surface is active with spots or convection, then its brightness will fluctuate naturally; if these fluctuations are larger than the dip caused by a small planet, the "jitter" will mask the planet's transit.

If a signal is weak, then collecting more data points over time and using mathematical filters allows the signal to be pulled from the noise; comparing data from multiple sources helps confirm the finding is not a telescope error.

If Earth's atmosphere distorts light waves and causes random brightness changes (twinkling), and if these changes are larger than 0.01%, then ground-based telescopes cannot reliably detect the tiny "blips" of Earth-sized worlds.

If a large object only partially overlaps the edge of a star, it will only block a small amount of light; if the amount of light blocked is small, the resulting dip can look identical to a small planet's full transit.

If the transit depth depends on the ratio of the planet's size to the star's size, and if M-Dwarfs are physically much smaller than the Sun, then a small planet will block a larger percentage of an M-Dwarf's light.

If light arrives as individual particles (photons), and if their arrival rate is naturally random, then the count of photons will vary slightly every second; this "shot noise" sets the fundamental limit on how small of a dip can be seen.

If the goal is to find Earth-like worlds, then missions focus on small radii, the correct distance for liquid water (Habitable Zone), and statistical surveys; mapping surface features is currently impossible with transits.

If a planet does not fully enter the disk of the star, the amount of light blocked will constantly change as it enters and leaves; if the blockage never levels off, the light curve will appear V-shaped rather than flat-bottomed.

If a transit is short and the telescope only samples the light every 30 minutes, it might miss the event entirely; if the sampling rate is too slow, the data cannot resolve the "blip" of a small, fast planet.

If a light curve shows a dip that looks like a planet, but the signal is weak, then scientists must verify it with other data before officially calling it a planet; therefore, it is initially labeled a candidate.

If a planet is closer to its star, the geometric probability that it will pass directly in front as seen from Earth is higher; if it is closer, it also completes its orbit faster, allowing for more "repeats" to confirm the signal.

If any non-planetary factor causes a small, periodic drop in the light recorded by the telescope, then it can mimic the signal of a small world; binary stars, spots, and electronics are all common sources of these errors.