3rd page of term paper
One main way scientists search for Earth-like planets around other stars is called Transit
Photometry. This method works by carefully watching a star’s light to see if it dims a little. If a
planet passes in front of its star, it blocks some of the star’s light, causing a small dip in
brightness. By studying these dips, scientists can guess the size of the planet, its distance from
the star, and if it might be in the “habitable zone”—the area where liquid water could exist,
which is important for life.
NASA’s Kepler Space Telescope used this technique to look for planets outside our solar system.
Launched in 2009, Kepler observed over 150,000 stars in one area of the Milky Way, looking for
tiny changes in light. Thanks to Kepler, scientists found thousands of possible exoplanets, some
similar in size to Earth and within their star’s habitable zone. These discoveries show there could
be billions of planets in our galaxy, and some might be rocky worlds like Earth.
Transit Photometry only works for planets that pass directly in front of their stars from our view,
so it misses some planets. But because Kepler watched so many stars, it’s been very successful.
It also allows scientists to confirm planets with other methods, like Radial Velocity, which gives
even more details. This approach gives hope that planets with Earth-like conditions may not be
rare and could be close enough for us to study further.
Bibliography
1.NASA Kepler Space Telescope, NASA, https://www.nasa.gov/?search=kepler.
2.“Exoplanet.” Wikipedia, Wikimedia Foundation,
https://en.wikipedia.org/wiki/Exoplanet.