Chapter 13, Problem 20EAP

Decide whether the statement makes sense lor is clearly true) or does not make sense (or is clearly false). Explain clearly, not all of these have definitive answers, so your explanation is more important than your chosen answer.

1. An extraterrestrial astronomer surveying our solar system with the Doppler method could discover the existence of Jupiter with just a few days of observation.
2. The fact that we have not yet discovered an Earth-size extrasolar planet in an Earth-like orbit tells us that such planets must be very rare.
3. Within the next few years, astronomers expea to confirm all the planet detections made with the astrometric and Doppler methods by observing transits of these same planets.
4. The infrared brightness of a star system decreases when a planet goes into eclipse.

. Some extrasolar planets are likely to be made mostly of water.

. Some extrasolar planets are likely to be made mostly of gold

Current evidence suggests that there could be 100 billion or more planets in the Milky Way Galaxy.

It’s the year 2020: The Kepler 2 mission has announced the discovery of numerous planets with Neptune-like orbits around their stars.

It’s the year 2020: Astronomers liave successfully photographed an Earth-size planet, showing that it has oceans and continents.

It's the year 2040: Scientists announce that our first spacecraft to reach an extrasolar planet is now orbiting a planet around a star located near the center of the Milky Way Galaxy.