NASA | DNA Building Blocks Can Be Made in Space

Mike Callahan, a NASA scientist, discusses the discovery of nucleobases in meteorites, suggesting their extraterrestrial origin. The research presents three key reasons: the presence of nuclear base analogs, differences between meteorite and terrestrial samples, and lab-simulated hydrogen cyanide reactions. These findings imply that meteorites could have contributed essential molecules for life on early Earth.

What are nucleobases and why are they important?

• They are large molecules found in proteins, essential for energy production.

• They are small molecules found in DNA and RNA, essential for life.

• They are compounds found in meteorites, used for fuel.

• They are molecules found in the Earth's crust, important for plant growth.

What is a nuclear base analog?

• A molecule that is completely different from nucleobases.

• A molecule found only in terrestrial samples.

• A molecule structurally similar to nucleobases but rare or absent on Earth.

• A molecule identical to nucleobases found on Earth.

Why do scientists believe nucleobases in meteorites are extraterrestrial?

• Because they are found in all terrestrial samples.

• Because they are identical to those found in Earth's soil.

• Because they are structurally different and rare on Earth.

• Because they are only found in the Earth's atmosphere.

What role does hydrogen cyanide play in the study of nucleobases?

• It is a byproduct of nucleobase formation on Earth.

• It reacts to form nucleobases similar to those found in meteorites.

• It is used to clean meteorite samples.

• It is a contaminant in meteorite samples.

How might meteorites have contributed to the origin of life on Earth?

• By forming the Earth's oceans.

• By creating the Earth's atmosphere.

• By seeding Earth with amino acids and nucleobases, building blocks of life.

• By providing essential nutrients for plant growth.