Tag Archives: Astrobiology

Liquid Water on Mars

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“Twelve orbits a day provide the Mars Global Surveyor MOC wide angle cameras a global “snapshot” of weather patterns across the planet. Here, bluish-white water ice clouds hang above the Tharsis volcanoes. This computer generated image was created by wrapping the global map found at PIA02066 onto a sphere.”–Via NASA

“2015” will appear on every mayor textbook as a significant year for scientific achievement. On October 5th, 2015 it was announced that there is unambiguous proof that brine (water with a lot of salt) flows on the martian surface during its warm months:

File:Dark Flows in Newton Crater Extending During Summer (animated).gif

From the press conference that NASA gave a few days ago:

The dark, narrow streaks flowing downhill on Mars at sites such as this portion of Horowitz Crater are inferred to be formed by seasonal flow of water on modern-day Mars. The streaks are roughly the length of a football field.

The imaging and topographical information in this processed view come from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.

These dark features on the slopes are called “recurring slope lineae” or RSL. Planetary scientists using observations with the Compact Reconnaissance Imaging Spectrometer on the same orbiter detected hydrated salts on these slopes at Horowitz Crater, corroborating the hypothesis that the streaks are formed by briny liquid water.

What does this mean for life? Does this discovery boosts expectations for martian life? Should we go up there? If so, what measures do we have to take once we reach these salty slopes?

Last post of the school year: The Arecibo Message

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The Arecibo message as sent 1974 from the Arecibo Observatory.

The Arecibo message as sent 1974 from the Arecibo Observatory.

Astrobiology is a field that is rapidly gaining momentum–due to scientific achievements such as the Curiosity Rover. This image should remind us of what we’ve achieved; how far we’ve come, and how much is still left to discover. The following excerpt, taken from Wikipedia, briefly explains the meaning of this image, along with its importance:

The Arecibo message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope on 16 November 1974. It was aimed at the globular star cluster M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony. The message consisted of 1679 binary digits, approximately 210 bytes, transmitted at a frequency of 2380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 1000 kW. The “ones” and “zeros” were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast was less than three minutes.

The cardinality of 1679 was chosen because it is a semiprime (the product of two prime numbers), to be arranged rectangularly as 73 rows by 23 columns. The alternative arrangement, 23 rows by 73 columns, produces jumbled nonsense. The message forms the image shown on the right, or its inverse, when translated into graphics characters and spaces.

Dr. Frank Drake, then at Cornell University and creator of the Drake equation, wrote the message, with help from Carl Sagan, among others. The message consists of seven parts that encode the following (from the top down):

1. The numbers one (1) to ten (10)
2. The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
3. The formulas for the sugars and bases in the nucleotides of DNA
4. The number of nucleotides in DNA, and a graphic of the double helix structure of DNA
5. A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
6. A graphic of the Solar System
7. A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish.