Part 1 a what do we know About Mars? Flashcards
Name the planets in order from the closest to the sun?
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune (Pluto - no longer considered a true planet)
How can Mars be compared similarly to in terms of topographical features?
They have mountains Valleys Different slopes Areas in full light and shadows Changes in Geology (different rock types and sediments)
Why are earth, mars, Venus and mercury considered terrestrial planets?
It means that they are earth like and refers to their solid rock interior. It separates them from the gas planets.
Which planets are considered gas planets and why?
Jupiter
Saturn
Uranus
Neptune
Because they are composed mostly of some combination of hydrogen, helium and water existing in various physical states
Approximately how far does the earth lie from the centre of the sun?
150000000000 m
(1.5 x 10^11 m)
Or 150 million km
How far away is the earth from the centre of the sun in astronomical units?
1.0 AU
What does 1 astronomical unit represent?
1.5 x 10^11 m
150 million km
150 000 000 000 m
How far is Jupiter from the centre of the sun?
5.2 AU
How far is Neptune from the centre of the sun?
30.0 AU from the Sun
Approximately how long does it take for Mars to orbit around the sun?
687 (earth) days to orbit around the sun
Approximately how long is a solar day in Mars?
24 hours 37 mins
How does the tilt of earth and Mars differ?
A comparison of the orbits or earth and mars. Mars’ orbit is more elliptical and more tilted (and the degree of the tilt varies more over time, giving more ‘wobbles’
On average how much further away is Mars from the Sun than earth is?
1.52 times as far from the Sun as earth is
What happens to kinetic energy as the temperature decreases?
The mean kinetic energy decreases and they move more slowly.
What is absolute zero?
It is the point that would be reached when the temperature has decreased to a point that molecule particles have no kinetic energy
On a Celsius scale what is the temperature of absolute Zero?
-273.15 degrees Celsius
What is the absolute temperature scale also known as?
The Kelvin scale
What is a change in one degree Celsius equivalent to in kelvins?
A changed in 1 kelvin is the same as a change in one degree Celsius
What is the normal freezing temperature of 0 degrees in kelvin?
273.15 k
What is the lowest air temperature measured on earth is degrees Celsius and kelvin?
- 89.2 degrees Celsius
183. 95 kelvin
What is the difference in the atmospheric pressure of earth and mars?
The atmospheric surface pressure of Mars is about 100 times less than that on earth. The average atmospheric pressure on Mars is about 6 millibars (me or mbar - either is fine)
The average on Earth is just over 1000 me.
What are the differences in the thickness of the atmosphere of Earth and Mars?
Mars has a slightly thicker atmosphere … average about 11 km in vertical height compared with 7 km on earth.
What is the major constituent of Mars atmosphere?
Carbon dioxide
What is the greenhouse affect?
It is the ability of the atmosphere to trap heat.
What composition of gases makes up the earths atmosphere?
Nitrogen
Oxygen
Argon
Water
What composition of gases make up the atmosphere of Mars?
Carbon dioxide
Nitrogen
Argon
Oxygen
What greenhouse gas have you heard of?
You may have said carbon dioxide, or possibly methane. Even though Co2 is the most prevalent anthropogenic greenhouse gas, the major greenhouse gas in the earths atmosphere, in terms of abundance, is actually water vapour. Other greenhouse gases include nitrous oxide, ozone (O3), and chlorofluorocarbons (CFCs)
How many polar ice caps are there in Mars?
Two
The north
And the south
What do both poles in Mars consist mainly of?
Water ice
With a thin layer of dry ice
What is dry ice?
It is frozen carbon dioxide
What percentage of the atmospheric Co2 is frozen in the polar region winters on Mars?
25-30 %
How thick is the dry ice in polar winters on Mars?
North - relatively thin layer of 1 m
South - 8 m thick
What is sublimation?
The transformation stage of solid to gas
What happens in the polar regions on Mars when summer comes?
When summer comes, and the pole is again exposed to sunlight, the frozen ice sublimes, creating enormous winds that sweep off the poles as fast as 400 km per hour. Thus the size of the polar caps varies markedly between summer and winter on Mars.
What is the main factor as to whether a solid will melt or sublime?
The pressure of the vapour of the particular substance surrounding the solid.
Can carbon dioxide exist as a liquid under the normal conditions on the Martian surface.
No the much lower atmospheric pressure means that liquid carbon dioxide certainly cannot exist here
What was the evidence that indicated that mars once had much more water?
Infrared telescopes on earth have revealed the ratio of normal to heavy water molecules in the atmosphere at different locations.
Heavy water molecules contain a heavy isotope of hydrogen called deuterium, which remains trapped in the Martian water cycle, while normal hydrogen is preferentially evaporated and lost to space. The researchers found water in the polar ice caps is highly enriched in deuterium, indicating that Mars has lost a tremendous quantity of normal hydrogen and hence a lot of water.
How big was Mars’s ocean estimated to be?
It was estimated to cover 20% of the planets surface area and be up to one mile deep.
Why did the ocean in mars shrink?
As mars lost its atmosphere over billions of years, it lost the pressure and heat needed to keep water liquid, so the water evaporated, causing the ocean to shrink.
How long did the ocean on Mars exist for?
The curiosity mission estimate was 1.5 billion years, but the new evidence suggests it could have been even longer than that
Would the emergence of life have time to develop in the period that Mars had its oceans?
Yes
