Saturn’s auroras in UV light.
An artist’s interpretation of the sky on Jupiter.
(via reddit and John Bianchi; Keep in mind that humans will probably never be able to go to Jupiter. As much fun as you’d think it would be, the extreme gravity and atmospheric pressure would be immensely difficult to deal with. Not to mention the magnetic field, which would interfere with electrical equipment. If we happened to get in the way of the moon Io, we’d be in trouble: Io interacts with Jupiter’s magnetic field and creates an electric current of 3 million amperes, which then creates lighting in the atmosphere of the planet (in comparison, a bolt of lighting on Earth has between 50,000 and 100,000 amperes). Then there’s the wind speeds of up to 224 mph (360 km/hr) and the fact that there’s no evidence for a solid surface and the temperature range from nearly absolute zero at the edge of the atmosphere (~2 K; -456ºF; -271ºC) to about 36,000 K at the center (64,340ºF; 35,726ºC). The point is that Jupiter is pretty rough. That doesn’t make it any less beautiful.)
Dwarf planet Pluto with one of it’s moon, Charon.
Charon’s relative large size to Pluto has some astronomers calling the Pluto-Charon a dwarf double-planet. Our Earth-Moon system is sometimes referred to by the same term (minus the “dwarf” distinction). Another thing that Pluto-Charon has in common with our system is they too are both tidally locked to one another: Charon always presents the same side to Pluto, and vice-versa.
When it comes to determining exactly where in the solar system life began, things have never been so up in the air. Scientists over the past decade have suggested deep-sea hydrothermal vents, underground aquifers, partially frozen lakes and even comets as locations for the origin of life.
Now an experiment that simulates chemical reactions in the atmosphere of Titan, Saturn’s haze-shrouded moon, adds a new location to the list of unexpected places where life could have begun — in the sky.
The study used radio waves as an energy source, simulating the action of ultraviolet radiation from the sun that strikes the top of Titan’s thick atmosphere and breaks apart molecules such as methane and molecular nitrogen. The experiment is the first to produce amino acids and the nucleotide bases that make up DNA and RNA — the basic ingredients of life — without the need for liquid water, says Sarah Hörst of the University of Arizona in Tucson.
The results suggest that Titan’s upper atmosphere, about 1,000 kilometers above the frigid moon’s surface, produces compounds capable of supporting life. And because planetary scientists believe that Titan represents a frozen snapshot of the early Earth, the study also indicates that terrestrial life might have formed within a primordial haze high above the planet rather than in a primordial soup on the surface, Hörst says.
Planetary scientist Jonathan Lunine of the University of Arizona, who was not part of the study, notes that the compounds found in the experiment “are relatively simple precursor molecules to life, and so there are a lot of additional steps between such molecules and life itself, most of which will likely require a liquid, such as water or methane.” However, he adds, everything that forms high in Titan’s atmosphere ends up in the moon’s lakes and seas of methane.
The study is provocative, Lunine says, because the Cassini spacecraft detected heavy ions in Titan’s atmosphere, but they were too massive for the craft’s instruments to identify. Amino acids were among the potential candidates for those heavy compounds, which were found in the terrestrial simulation.
To confirm that amino acids and nucleotide bases are actually produced in Titan’s atmosphere will require an orbiter that can carry instruments 100 to 200 kilometers deeper than Cassini does into Titan’s haze layer, Lunine says.
From: Wired Science
Written By: Ron Cowen
Beneath its dreary shroud of clouds, Venus could be positively hopping: Planetary geologists have spotted a lava flow they say is just decades old. If confirmed, it would be the youngest evidence for volcanism on Venus.
“The flow we studied seems to be very young — it is still warm inside,” says Nataliya Bondarenko, a planetary scientist at the University of California, Santa Cruz. She and her colleagues describe their findings in an upcoming issue of Geophysical Research Letters.
Researchers have long thought that Venus must be geologically active, since more than 1,000 volcanoes dot its surface. But scientists have struggled to gather definitive evidence that the planet is active today, like Earth, and not long dead, like Mars.
Bondarenko’s team analyzed microwave data collected by NASA’s Magellan mission, which orbited Venus in the early 1990s. Microwave radiation indicates heat coming from the planet, such as a lava flow in the process of cooling.
In the Bereghinia Planitia region in Venus’ northern hemisphere, the team found a flow that appeared up to 85 degrees Celsius hotter than expected. Had the flow been more than a century old, Bondarenko says, it would have cooled down enough that Magellan wouldn’t have spotted any excess heat.
The flow must have been at least 15 years old when detected by Magellan, she says, because the Pioneer Venus orbiter photographed it in 1978.
But there’s little other evidence supporting Bereghinia Planitia as recently volcanically active, says Suzanne Smrekar, a planetary geologist at the Jet Propulsion Laboratory in Pasadena, California.
In April, Smrekar and colleagues published a paper in Science describing lava flows from three regions in Venus’ southern hemisphere. All three were places known to be hot spots of geological activity, similar to Hawaii. Using data from the European Space Agency’s Venus Express mission, currently orbiting the second planet, Smrekar’s team found several flows that looked fresh. The flows’ unweathered appearance, compared with the surrounding landscape, suggests that they formed no more than 2.5 million years ago and probably in the past 250,000 years, the team concluded.
Because the Venus Express data come only from the southern hemisphere, they can’t say anything about whether Bereghinia Planitia is also active, Smrekar says. But any claim of a decades-old flow in the north “sort of falls into the ‘extraordinary claims require extraordinary proof’ category,” she says.
Taken from: Wired Science
Written by: Alexandra Witz
Jupiter’s moon Ganymede
Ganymede was discovered by Galileo in 1610. Ganymede is the largest moon in the solar system. The whitish north polar cap, upper right, is covered in water ice. Ganymede’s mass is 2.02 times that of our moon, giving it the highest mass of all moons in our solar system as well.
Upcoming mission: Juno
Juno will be the first solar-powered spacecraft to visit Jupiter. Juno launches August 2011. Juno will be studying Jupiter’s powerful radiation belts, along with it’s auroras, planetary core and magnetic fields, amongst many other things.
Some objectives of Juno
- To find the ratio of oxygen to hydrogen, effectively measuring the abundance of water on Jupiter, which will help distinguish among prevailing theories linking the gas giant’s formation to the solar system.
- Precisely measure Jupiter’s magnetic field to assess the origin and structure of the field and how deep in Jupiter the magnetic field is created. This will help scientists understand the fundamental physics of dynamo theory.