Alternate Realities or Parallel Universes

These are self-contained, co-existing with one’s own. Multiverses are groups of universes. This is only fantasy now, but what if there was a parallel universe born with every choice we make, and ever have made. In fact right now as I write this and as you read this it is ultimately possible that you are creating endless amounts of parallel universes within a multiverse of possibilities.

This idea is found throughout mythology as well as books, sci-fi as well as others. In dark fantasy or horror it is often the place for hiding things. In Narnia, this is the place where a whole other life is lived.

Mars Moon Phobos Likely Forged by Catastrophic Blast

One of the two moons of Mars most likely formed from rubble catapulted into space after a comet or meteorite slammed into the Red Planet, a new study finds.


The moon, Phobos, looks a lot like an asteroid: It's lumpy, potato-shaped and very small. It has an average radius of just 11 kilometers (6.8 miles).

Scientists have long wondered about the origin of Phobos — is it merely a captured asteroid, the leftovers from Mars' formation or evidence of a cosmic Martian hit-and-run with another object?

The new study found that the moon's composition and density strongly indicate that, like the leading theory for Earth's own moon, Phobos is the result of a catastrophic impact with its parent planet.

Phobos is one of two moons of Mars. The other, Deimos, is smaller than its partner.

What makes a Phobos?

Researchers used data from the European Space Agency's Mars Express spacecraft to study Phobos' composition.

By analyzing the probe's infrared observations, astronomers found that Phobos and asteroids don't seem to be made of the same stuff. Instead, the moon has many minerals also seen on Mars, suggesting a common origin for the two bodies.

The team also found so-called phyllosilicates — minerals that can form in the presence of water — on Phobos. Phyllosilicates have been detected on Mars, too.
"This is very intriguing as it implies the interaction of silicate materials with liquid water on the parent body prior to incorporation into Phobos," said study co-author Marco Giuranna of the Istituto Nazionale di Astrofisica in Rome, Italy. "Alternatively, phyllosilicates may have formed in situ, but this would mean that Phobos required sufficient internal heating to enable liquid water to remain stable."

Independent observations from NASA's Mars Global Surveyor spacecraft support the composition data from Mars Express, the researchers said.

The research was presented Sept. 20 at the European Planetary Science Congress in Rome, Italy, and has been submitted to the journal Planetary and Space Science.

Too spongy for an asteroid

During the study, evidence piled up to rule out the captured-asteroid scenario for Phobos, researchers said.

The first sign came while they were studying the Martian moon's density to see how it matched with that of asteroids. They determined the density of Phobos to be about 1.86 grams per cubic centimeter.

"This number is significantly lower than the density of meteoritic material associated with asteroids," said Pascal Rosenblatt of the Royal Observatory of Belgium. "It implies a sponge-like structure with voids making up 25 to 45 percent of Phobos' interior."

Other evidence points toward a relatively spongy Phobos, too.

If it were denser, the moon probably wouldn't have survived the massive impact that created its Stickney Crater, Giuranna said. Stickney is about 10 km (6 miles) across — nearly half as wide as all of Phobos.

In addition, the researchers said, a highly porous asteroid — if that's what Phobos once was — probably would not have survived being captured by Mars' gravity.

Yet sponginess is consistent with the impact-formation hypothesis for Phobos, they added. Chunks of rock and rubble blown off Mars' surface would accrete somewhat haphazardly in its orbit, leaving interior pockets and voids.

Finally, the motion of both Phobos and its sister moon Deimos — which is also small, rocky and lumpy—argue against the asteroid-capture scenario, according to the researchers. Their orbits are too neat — too circular and too close to the Martian equator — for a couple of snagged space rocks, researchers said.

More missions, more data

Despite the evidence from Mars Express, more observations are still needed before scientists can conclusively determine the origin of Phobos, the researchers said.

The Russian Phobos-Grunt mission, set to launch in 2011, could help settle the question. Phobos-Grunt aims to land on Phobos, grab soil samples ("Grunt" being the Russian word for "soil") and return with them to Earth. Such samples could be compared to Martian meteorites that have landed on Earth.

Similar studies of lunar soil samples have shown that Earth and our moon are likely made of the same stuff. This determination helped scientists come up with the leading theory of our moon's formation: A long-ago catastrophic impact.

Hellish Venus

It may seem downright bizarre, but a new model of Venus' super-hot atmosphere suggests its greenhouse gases may actually be cooling the planet's interior.

These gases initially cause Venus' temperature to rise, but at a certain threshold, they can trigger dynamic processes – which researchers call "mobilization" – in the planet's crust that cool the mantle and overall surface temperature, researchers found.

Venus surface temperature, on average, is a scorching 860 degrees Fahrenheit (460 degrees Celsius).

"For some decades we've known that the large amount of greenhouse gases in the atmosphere of Venus cause the extreme heat we observe presently," said study leader Lena Noack of the German Aerospace Center in Berlin.

Carbon dioxide and other greenhouses gases that led to Venus' hellish temperature were belched into the planet's atmosphere over time through erupting volcanoes.

Noack and her colleagues examined the interaction of carbon dioxide and other greenhouse gases in Venus' atmosphere and conclude that the planet may have been even hotter than it is today, Noack said.

"But at a certain point this process turned on its head – the high temperatures caused a partial mobilization of the Venusian crust, leading to an efficient cooling of the mantle, and the volcanism strongly decreased," Noack said. "This resulted in lower surface temperatures, rather comparable to today's temperature on Venus, and the mobilization of the surface stopped."

Noack and co-author Doris Breuer built a one-of-a-kind Venus computer model in which the planet's hot atmosphere was paired with a 3-D model of the interior.

Unlike on Earth, Venus' high temperatures have a much bigger effect on the rocky surface, which ultimately loses its insulating qualities, the researchers said.

"It's a little bit like lifting the lid on the mantle: The interior of Venus suddenly cools very efficiently and the rate of volcanism ceases," Noack said. "Our model shows that after that 'hot' era of volcanism, the slow-down of volcanism leads to a strong decrease of the temperatures in the atmosphere."

Their models also suggested differences in the time and place in which the volcanoes resurfaced Venus over time.

So even as Venus' atmosphere cooled, there would remain a few active volcanoes which resurface some spots with lava flows, researchers said. In fact, some of these volcanoes might be active even today, according to recent results from the European Space Agency's Venus Express mission.

Venus Express launched in 2005 and arrived at the cloud-covered planet a year later. The spacecraft recently detected 'hot spots' on Venus, or areas of unusually high surface temperatures, at volcanoes that were previously thought to be extinct.