Question

As you know from Part D, most planets are undetectable by the transit method. Nevertheless, scientists have put great effort and expense into observing programs that rely on the transit method, including the Kepler mission, the TESS mission, and the CHEOPS mission. In one to two paragraphs, briefly explain why the transit method is considered so valuable despite its limitations.

Answer 1

Answer:

See explanation below:

Explanation:

Transit Photometry is the most widely-used and effective to date, it has been a method that measures the light curve of distant stars for periodic dips in brightness. These are the result of exoplanets passing or transiting in front of the star relative to the observer. It is currently the most effective and sensitive method for detecting extrasolar planets, particularly from an observatory in space. When combined with radial velocity data, a transit can also provide a good estimate of the planet's mass. This method detects distant planets by measuring the minute dimming of a star as an orbiting planet passes between it and the Earth.

The main reason direct detection of exoplanets is difficult is because most planets orbit  planets orbit at small angular separations on the sky, this means a direct detection is only possible if the star's light can be suppressed or occulted such that the faint light from the planet can be detected.

Some planets are found via the wobble method, using both methods, combining mass and size, scientists can calculate the planet's density, an important step towards assessing its composition.