Spark Detection Approximately How Many Other Planetary Systems Have Been Discovered To Date?

Approximately how many other planetary systems have been discovered to date? - spark detection

Approximately how many other planetary systems found so far?

ten)
b) one million
c) One hundred
d) Ten thousand
e) thousand

What was the Cambrian explosion?

a) the first spark of lightning, that the first life, created from amino acids
b) the impact of meteorites, which have led to the extinction of the dinosaurs
c) diversification of life drama that began 540 million years ago
d) the eruption of the volcano as Cambria in the supercontinent Pangea known old
e) the largest mass extinction in Earth history

Which of the following methods are not yet known planets around other stars?

a) evidence of periodic changes in the Doppler spectrum of a star
b) detecting loss of light as a planet transits a star
Proof c) the reflected light from the planet
d) evidence of periodic fluctuations in the position, a star in the sky
e) All of the above have been successful.

Most of the planets discovered around other stars

A less)massive than the Earth and train close to the star.
b) have less mass than the Earth and orbit far from the star.
c) are more massive than Earth and orbit the star very close.
d) are more massive than Earth and orbit far from the star.
e) are found around neutron stars.