Astronomy Astrobiology and the Search for Life 3

Question 1

What does SETI stand for?

Accepted Answer

Search for Extraterrestrial Intelligence

Answer

SETI is the scientific discipline dedicated to detecting signals or evidence of intelligent life beyond Earth, primarily through radio and optical telescope surveys.

Question 2

The Fermi Paradox highlights the contradiction between:

Accepted Answer

The high estimated probability of extraterrestrial civilizations and the complete absence of evidence for them

Answer

Enrico Fermi noted that given the vast number of stars and the age of the galaxy, intelligent civilizations should be common and detectable, yet we have found no evidence of any.

Question 3

Carbon is considered the backbone of known life primarily because:

Accepted Answer

It forms four covalent bonds and can create large, complex, stable molecules

Answer

Carbon's four valence electrons allow it to bond with many other elements in countless arrangements, enabling the vast molecular complexity required for biological processes.

Question 4

Saturn's moon Enceladus is a strong candidate for habitable conditions because:

Accepted Answer

Geysers near its south pole eject water vapor from a confirmed subsurface liquid ocean

Answer

Cassini spacecraft data confirmed that Enceladus vents water, salts, silica particles, and organic molecules into space from a warm, salty subsurface ocean through cracks in its icy crust.

Question 5

In SETI research, a 'technosignature' is best defined as:

Accepted Answer

Observable evidence of technology produced by an intelligent civilization

Answer

Technosignatures encompass any detectable artifact of technology — radio signals, laser pulses, megastructures, or industrial pollutants — that would indicate an intelligent technological civilization.

Astronomy Practice Test

Astronomy Practice Test

Astronomy Astrobiology and the Search for Life 3