Been a while since I last updated, I’ll focus on what’s happened recently.
Extrasolar Planets Discovered
Earlier this month it was made known that astronomers had, for the first time, taken the first direct photographs of planets outside of the solar system. Like most other planets discovered to this point, they are all large gas giants, Jupiter size or larger, but unlike many extrasolar planets discovered to this point, they all orbit their parent stars at respectably far distances. The most recent extrasolar planet photographed, orbiting the star Beta Pictoris and known simply as Beta Pictoris b (”b” for the second planet discovered around the star) orbits at a distance comparable to Saturn’s around our sun (which takes about 29.5 years to make one orbit.)
Beta Pictoris is a fairly young system only 63 light years away from Earth. What makes it so unique is that a debris cloud has been observed to surround the star, comparable to what many astronomers believe existed around the Sun when planets like Earth were being formed. The system is only 8-20 million years old, which is young in celestial terms. However because the star is so hot, it will only burn for another 20 million years before it burns out. For comparison, the solar system is 5 billion years old, with Earth’s estimated age being approximately 4.6 billion years old. This means that it took about 400 million years before the Earth fully materialized out of the debris cloud surrounding the Sun, so even though Beta Pictoris appears to be similar to the solar system in terms of planetary placement, it is in fact very different. It is unlikely that any rocky planets will fully form in this turbulent system, let alone even primitive life.
http://www.sciencedaily.com/releases/2008/11/081121081105.htm
Water on Enceladus
In space news closer to home, the Saturnian moon Enceladus is now believed to harbor liquid water. This theory, while only on paper before, now has new evidence. Using pictures from the orbiting Cassini spacecraft, scientists have been able to analyze the speed at which material is being ejected from geysers on Enceladus. That speed is now estimated to be around 1360 mph. The theory goes like this:
…[T]he behavior of the geysers supports a mathematical model that treats the [geyser] vents as nozzles that channel water vapor from a liquid reservoir to the surface of the moon. By observing the flickering light of a star as the geysers blocked it out, the team found that the water vapor forms narrow jets. The authors theorize that only high temperatures close to the melting point of water ice could account for the high speed of the water vapor jets.
If the existence of liquid water on Enceladus can be confirmed, that would make yet a third world in the solar system with this essential chemistry for the formation of life. Other than Earth, Jupiter’s moon Europa is currently believed to have an ocean of water beneath a surface of ice. Geothermal vents on the ocean floor, much like those that are found on the bottom of Earth’s oceans, are believed to harbor primitive forms of life.
http://www.sciencedaily.com/releases/2008/11/081126133405.htm