Enjoy our starry night skies
Be a considerate neighbor: Reduce nighttime glare. Shield your outside lights downward.
November 15 at 8:00 p.m.
nOVEMber 2011 Night Sky
Aliens—There May be Aliens Everywhere
Science has been speculating for years now about life somewhere besides Earth. Astronomers have looked at Mars as a prime target for water-carbon based life. Robots have searched the surface for signs of life without finding conclusive evidence—lots of possible chemical signatures do exist there.
Just what signatures do we look for when seeking life? The presence of water or water vapor in the atmosphere would be encouraging, but there was water on Earth before life. Other indicators that point to life are molecular oxygen and ozone. Life on Earth takes in oxygen and exhales carbon dioxide. Then, carbon dioxide seems to be present where there is no life like on Venus and Mars. Some forms of life we know are anaerobic, they do not need oxygen and emit methane.
If life does exist on Mars, it is probably underground. Many minerals that form in water have been found on the surface, and there are erosion-like channels visible from orbit. Underground Mars may still be wet. There are also some suspicious emissions of methane during the Martian spring. Is Mars alive? We may need to dig to find out.
More recently, exobiologists have turned an eye further out in our solar system—Jupiter and Saturn. It is thought that the sunlight was too dim and the temperatures too cold for life. Then our probes found liquid water on the moons of the Jovian planets. Where there is liquid water, science believes, there is the possibility of life. Where there is energy to create a food source, life can thrive.
So, below thick surfaces of ice, Jupiter’s moon Europa is believed to host a global ocean up to a hundred miles thick. Recent computer simulations from oceanographer Robert Tyler at the University of Washington, shows that Jupiter may have bigger effects on Europa than once thought. Rather than just squeezing the rocks and flexing a global shell of ice, Jupiter’s tugging may also generate huge planetary waves in Europa’s submerged ocean.
Europa travels a slightly oblong orbit around Jupiter. When it reaches the sharper curves at either end of its orbit, the moon wobbles to release pent-up energy, which translates into tides. Europa, like Earth, may dissipate most of its tidal stresses in oceanic waves, spreading heat around the moon. And the icy ocean is being fed more than a hundred times more oxygen than previous models had suggested, according to new research. Oxygen is created when charged particles from Jupiter’s magnetic field hit the ice. Researchers think it would have taken one to two billion years for the first surface oxygen to reach the ocean below.
At least three million tons of fish-like creatures could theoretically live and breathe on Europa, according to researcher Richard Greenberg of the University of Arizona in Tucson. Based on what we know about the Jovian moon, parts of Europa’s seafloor may resemble the environments around Earth’s deep-ocean hydrothermal vents. Is there life there? More investigations are needed.
Then there is Titan. Titan is the only moon around Saturn to have a dense atmosphere and a complex surface chemistry. Astronomers claim the moon is generally too cold to support even liquid water on its surface. Two new studies show that hydrogen gas flowing throughout the planet’s atmosphere disappeared at the surface, suggesting that alien forms could in fact breathe. It also concluded that there was a lack of hydrogen on the surface. Scientists could be led to believe it had been possibly consumed by life. Researchers had expected sunlight interacting with chemicals in the atmosphere to produce acetylene gas. But the Cassini probe did not find any. Hydrogen consumption is the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth. If true, it would be exciting because it would represent a second form of life independent from water-based life on Earth.
The Planets and the Moon
- Look for Mercury low in the southwest just after sunset through mid-month.
- Venus, too, will be low in the southwest at sunset this month. Find the Moon-Venus conjunction on the 26th, thirty minutes after sunset in the southwest.
- Mars rises in the east around midnight all month. There will be a Mars-Regulus conjunction on the 10th, two hours before sunrise in the southeast.
- Jupiter will be low in the east after sunset. Look two hours after sunset on the 9th for Jupiter and the moon in the eastern sky.
- Look quick near the western horizon at sunset the first week of the month for Saturn. On the 22nd, look for a Saturn-Spica-Mars conjunction in the southeast one hour before sunrise.
- Daylight Savings time ends on the 6th.
- The Moon is full at 1:16 p.m. on the 10th and new at 11:10 p.m. on the 24th.
- There is a partial solar eclipse on the 25th, only visible from Antarctica and New Zealand.