Presentation on theme: "Evidence of Life on Mars? Nanobacteria may hold the key."— Presentation transcript:
Evidence of Life on Mars? Nanobacteria may hold the key.
Eight years ago, nanometer-sized features resembling bacteria were discovered in a Martian meteorite known as ALH84001.
ALH84001 is believed to have broken off Mars millions of years ago when a meteor hit the planet.
As scientists were analyzing ALH8400, they found features that resemble bacteria. These features measure only 20 to 100 nanometers across.
How do we know ALH84001 came from Mars? ALH84001 was found in Antarctica in 1984. It is partly covered with black glass called fusion crust, which forms on all meteorites when they burn through the Earth’s atmosphere.
If a dot falls on the diagonal line, the gas is found in similar amounts in both Mars’ atmosphere and the asteroid. Mars’ distinctive atmosphere was analyzed by the Viking Lander in 1976. The meteorite contains traces of gas just like the Martian atmosphere. How do we know ALH84001 came from Mars?
What is a nanometer? One Nanometer is.000000001 meters, or one millionth of a millimeter. 1 inch = 25,400,000 nanometers 1 nanometer = width of 6 bonded carbon atoms (40,000 bonded carbon atoms = width of a human hair) The period at the end of this sentence is about 1 million nanometers long. A red blood cell is about 7,000 nanometers in diameter and 2,000 nanometers high.
Although some scientists think nanometer-sized life can't exist, others contend that nanobacteria are the new frontier in life science.
Some scientists believe that since enzymes and genetic material can only be certain sizes, organisms smaller than 200 nanometers in diameter could not be self-sustaining and therefore could not be considered be "life." Others say that life can be that small, and claim to have grown nanobacteria in the laboratory. A new study reports that protein balls measuring 40 to 120 nanometers are produced when bacterial enzymes cause organic material to decay. Therefore, decayed organic material could have caused the nano-size features in ALH84001. Theories about Nanobacteria
To date, no life as been confirmed on Mars or in meteorites from Mars. But scientists continue to examine meteors and the planet itself for any signs.