Lecture 12 - Mars

why was giovanni schiaparelli fameous

for drawing mars

where did canali come from

giovanni schiaparelli drew mars with straight lines as canali - it was misinterpreted as meaning canals and therefore assumed to be artificial so indicated evidence of civillisation on mars

who was percival lowell

inspired by schiaparelli work and proposed a case for life on mars was taken up by leading US academic who built an observatory specially to study canals on mars

what was the popular opinion of canals

thought to be a result of attempts by the martians to irrigate the planet from the melting polar caps

what was the popular opinion vs reality

• lowell mapped 437 individual canals

• suggested that many of these met at oases at which they got their water

• none of this is currently believed to be correct

why was there life thought to be on mars in the 1938

• H.G.Wells’ now-famous book “War of the Worlds” (first appeared in serialized form in 1897) was read out over the radio in New York.

• It was done in such a dramatic manner that many thousands of Americans were convinced that aliens from Mars had landed and were taking over the planet

what are the face on mars and pyramid pictures

came from an early NASA satellite observatory

what is the mars conspiracy of inca city

• set of intersecting, rectilinerar ridges located at the south polar region of mars, first seen in images taken in 1972

• they showed superficial resemblance to ancient ruins

what is the martian metorite

ALH 84001 found in 1984 in antartich

how large is ALH 84001

1.93 kg, potato sized meteorite h

how old is ALH 84001

4.5 billion years old

why did ALH 84001 gain a lot of attention

• an electron microscope revealed structures that were considered to be the fossilized remains of bacteria- like lifeforms.

• As of 2005, scientific consensus was that the microfossils were not indicative of Martian life, but of contamination by Earthly biofil

how did evidence of ALH84001 contain martian water

• chemical analysis showed that it contained abundant inclusions of distinctively layered sequences of Ca-Mg-Fe carbonates

could there be hydrothermal vents on mars

• the carbonates in ALH 84001 consistent with hydrothermal fluids consistent to volcanic vents on earth

• however they are unkown as of now

could ALH84001 contain microfossils

• electron microscopic study reveals
  elliptical, rope-like, and ubular structures* in fractures in thecarbonate mineral globulel

• The structures are possible fossil bacteria, showing similarity with the oldest microfossils found on Earth

is there earth like fossils in ALH 84001

nano fossils were found in the meteorite that are also found on earth so maybe yes!

why did it take so long for the ALH 84001 meteorite take to get into a newspaper

• preserved for study

• many of the findings were reported in 1996 were only made possible only because of more recent technology

how many meteorites were identified that match unique martian chemistary

12

what is the zagami

a meteorite that landed in nigeria

• it is made of basalt and carved into thousands of pieces ad has been the subject of lots of scientific papers

what is important about the zagami meteorite

researchers found compelling evidence that the rock came from mars

how didALH84001 get to earth from mars

• it must have left its surface going faster than mars escape velocity

• The only known natural process that can get rocks moving so fast is a meteorite impact

what is mars escape velocity

5 km/s

how big must the asteroid be to throw ALH 84001 into the atmosphere

1km in size around 16 million years ago

what happened once ALH84001 left mars

• it orbited the sun on its own like a small asteroid

• started out with an orbit nearly like mars but its orbit changed each time it passed close to mars or collided with an asteroid

• gravity from the other planets slowly nudged ALH 84001 farther and farther from mars

• the orbit of ALH84001 changed enough so that it came near earth’s orbit and 13,000 years ago the earth

what is the current understanding of water on mars

liquid water is possible on the surface of mars and likely that it did have it in the past