Life In The Cosmos Flashcards
Why are closed membranes essential in the development of complex biology ?
The enable the emergence of complex molecules from the surrounding equilibrium
The extinction of dinosaurs occurred about 64 million years ago at the boundary between what eras?
Cretaceous and paleogene
The most severe extinction occurred 250 million years ago at the boundary between what eras
Permian and Triassic
What is life on Earth mainly composed of?
Carbon, oxygen and hydrogen
Of the sun were to get 20% hotter what would happen to the habitable zone?
It would move further away from
What have probes sent to Mars found?
Ice caps of frozen carbon dioxide and water
What are Mars’s outflow channels evidence for?
Vast ancient floods
What is believed to be the reason for liquid water under the surface of Europa?
As a result of tidal friction caused by tidal stressing
What is the frequency range for the cosmic water hole?
1.4 - 1.7 GHz
What is the Fermi paradox?
The lack of signs of alien life despite the high probability of the existence of extraterrestrial life
What is the fundamental nuclear reaction in the sun?
Fusion of hydrogen to helium
What happens in the accretion phase in the early solar system?
Particles grow by colliding and sticking together
On the scale of the geological year, in which the history of earth is compressed to 1 year, how long has human civilisation existed for
3 hours
What is the name for a reaction where more energy comes out than was put in?
Exothermic
If Earth had no greenhouse gasses, what would happen to the surface temperature?
It would be below freezing
Where is the habitable zone?
Beyond the orbit of Venus to inside the orbit of Mars
What observation showed that life may have been suitable on Mars?
Dried up river beds
Why is Europa a good candidate for the possible existence of life?
It has a deep subsurface ocean of liquid water
When were the first planets to orbit around other stars discovered?
At the end of the 20th century
For a planet detected by the Doppler technique, what does the repeating pattern of stellar motion tell us
The orbital period
For a planet detected by the Doppler technique, what does the repeating pattern of stellar motion tell us
The orbital period
What is the source of energy that keeps the sun shining
Nuclear fusion
What is accretion in terms of planetary formation?
The growth of planetesimals from smaller solid particles that collided and stick together
How did molecular oxygen get into the Earths atmosphere?
It was released through photosynthesis
In the geological calendar where the history of the universe is compressed to 1 year, what month did the dinosaurs go extinct?
Late December
What was the Cambrian explosion?
A dramatic diversification of life that began about 540million years ago
What defines a habitable region around a star?
The region were liquid water can exist
What is the primary way that the search for extra terrestrial intelligence (SETI) is carried out?
By using radio telescopes to search for signals from other civilisations
