Europa, an Ice Moon of Jupiter may be home to extraterrestrial life
On 22 February 2017, NASA scientists announced their discovery of seven Earth-sized planets within a potentially habitable zone around the dwarf star TRAPPIST-1. The possibility of finding life off Earth captivated the world. While not far away, in terms of astronomical distance, these planets are still a long way off. A spacecraft traveling at the speed of light, would take 39 years to get there. With our current technology, we could not get there any where near that quick. The fastest space craft launched so far would take over 800,000 years to get close. While in time we will develop faster ships, for now life on these planets remains shrouded in mystery.
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| Europa, Earth & Moon shown in comparison Credit: NASA/JPL |
Fortunately, we have possibly habitable environments much closer to home. However, it will still take around 6 years to make the 390 million mile journey to one of the most likely off-planet destinations. Plans are in place the journey to Europa, an icy moon of Jupiter.
Europa, discovered by Galileo Galilei in 1610, is the 6th largest moon in the Solar System. Europa consists of silicate rocks, with a water-ice crust, and an iron-nickel alloy core. It has a thin atmosphere of mostly oxygen. NASA will launch the mission hopefully sometime in the next five years. This trip may bring back strong evidence for life off our home planet.
At some point, landing a space probe on the surface of Europa could provide direct evidence of living organisms on this icy moon. The first steps towards this discovery will be a series of 45 flybys, traveling anywhere between 16 and 1700 miles of the surface. Scientists at NASA and the Jet Propulsion Laboratory (JPL) designed the Europa Clipper to get the job done. The spacecraft will be equipped to gather high resolution images of the surface, along with detailed information about the atmosphere, and the thickness of the ice sheets covering the moon. Accurate measurements of the thickness of the icy crust be taken as well.
Here on Earth, geologists use radar technology to probe beneath surface ice areas around the North and South pole. The Europa Clipper will be able to use similar instruments to seek out lakes and oceans buried deep. Even more sensitive devices will be able to sort out how deep these oceans may be, and just how salty.
It may seem hard to imagine that life could exist in such deep places. We normally think that life depends on ultraviolet light and warmth from the Sun. Sunlight is critical for photosynthesis, without which plants can not grow. However, around geologically active thermal vents deep in Earth's ocean, life has been found. Life in such extreme conditions depends on energy gained from the warmth of the Earth and by breaking down energy stored in minerals. Forms of life similar to those living near deep-sea vents could occur someplace else. The Europa Clipper's equipment will be able to detect areas of increased temperature, that might imply life sustaining conditions below the icy crust. We already suspect that geysers of liquid water have erupted from Europa. The Hubble Space Telescope found evidence of this in 2012. Such activity is suggests that there is sufficient energy on Europa to support life.
The Europa Clipper mission
At some point, landing a space probe on the surface of Europa could provide direct evidence of living organisms on this icy moon. The first steps towards this discovery will be a series of 45 flybys, traveling anywhere between 16 and 1700 miles of the surface. Scientists at NASA and the Jet Propulsion Laboratory (JPL) designed the Europa Clipper to get the job done. The spacecraft will be equipped to gather high resolution images of the surface, along with detailed information about the atmosphere, and the thickness of the ice sheets covering the moon. Accurate measurements of the thickness of the icy crust be taken as well.
Here on Earth, geologists use radar technology to probe beneath surface ice areas around the North and South pole. The Europa Clipper will be able to use similar instruments to seek out lakes and oceans buried deep. Even more sensitive devices will be able to sort out how deep these oceans may be, and just how salty.
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| Artist's depiction of the Europa Mission Spacecraft Credit: NASA/JPL-Caltech [Public domain], via Wikimedia Commons |
Life under the ice of a distant moon?
It may seem hard to imagine that life could exist in such deep places. We normally think that life depends on ultraviolet light and warmth from the Sun. Sunlight is critical for photosynthesis, without which plants can not grow. However, around geologically active thermal vents deep in Earth's ocean, life has been found. Life in such extreme conditions depends on energy gained from the warmth of the Earth and by breaking down energy stored in minerals. Forms of life similar to those living near deep-sea vents could occur someplace else. The Europa Clipper's equipment will be able to detect areas of increased temperature, that might imply life sustaining conditions below the icy crust. We already suspect that geysers of liquid water have erupted from Europa. The Hubble Space Telescope found evidence of this in 2012. Such activity is suggests that there is sufficient energy on Europa to support life.
The Europa Clipper's carry-on luggage
If you are going to spend 6 years traveling 390 million miles to the neighborhood of Jupiter, you want to come well prepared. The spacecraft will bring along:- Plasma Instrument for Magnetic Sounding (PIMS)
- Interior Characterization of Europa using MAGnetometry (ICEMAG)
- Mapping Imaging Spectrometer for Europa (MISE)
- Europa Imaging System (EIS)
- Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)
- Europa THermal Emission Imaging System (E-THEMIS)
- MAss SPectrometer for Planetary EXploration/Europa (MASPEX)
- Ultraviolet Spectrograph/Europa (UVS)
- SUrface Dust Mass Analyzer (SUDA)
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