Energy bubble could enable warp speed travel

Einstein, eat your heart out: a space-time bubble could enable travel at light speed and beyond.

Physicists at Baylor University in Texas are working on a method to make the theoretical Alcubierre ('warp') drive a reality.

Proposed in 1994, the Alcubierre drive expands the fabric of space behind a spaceship into a bubble, while shrinking space-time in front of the ship.

The ship would not actually move; rather, space would move around the ship. The theory thus complies with Einstein’s Theory of Relativity, which states that it would take an infinite amount of energy to accelerate an object faster than the speed of light.

Warp drives have, so far, remained in the realm of science fiction due to there being no known methods to create a warp bubble.

Now, the Baylor University researchers theorise that such a bubble could be formed by manipulating the 11th dimension to create dark energy.

Dark energy is a hypothetical form of energy that is said to be responsible for accelerating the expansion of the universe.

The researchers estimate that the amount of energy needed to influence the extra dimensions is equivalent to the entire mass of Jupiter being converted into energy.

“That is an enormous amount of energy,” said Gerald Cleaver, an associate professor of Physics at Baylor. “We are still a very long ways off before we could create something to harness that type of energy.”

More information is available from Baylor University's press release.

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Martian mountain could imply life

A study of the Martian volcano Olympus Mons has found that pockets of ancient water may still be trapped under the mountain.

Conducted by Rice University geophysicists Patrick McGovern and Julia Morgan, the study could help answer the question of whether the Red Planet ever had -- or still supports -- life.

Olympus Mons is about three times the height of Mount Everest and stands almost 15 miles high. It slopes gently for a distance of more than 150 miles from the foothills to the caldera.

The researchers modelled the formation of Olympus Mons with an algorithm known as particle dynamics simulation and determined that only the presence of ancient clay sediments could account for the volcano's asymmetric shape.

The presence of sediment indicates water was or is involved.

"What we were analyzing was the structure of Olympus Mons, why it's shaped the way it is," said McGovern, an adjunct assistant professor of Earth science and staff scientist at the NASA-affiliated Lunar and Planetary Institute.

"What we found has implications for life -- but implications are what go at the end of a paper," he noted.

Similar to volcanoes in Hawaii, Olympus is expected to have been able to grow to its size because of the clay's friction-reducing effect.

The researchers suspect that if they were able to stand on the northwest side of Olympus Mons and start digging, they'd eventually find clay sediment deposited there billions of years ago, before the mountain was even a molehill.

The researchers are interested in what may be trapped underneath the mountain, as there may still be fluids, and potentially life, embedded in the clay sediment.

"This deep reservoir, warmed by geothermal gradients and magmatic heat and protected from adverse surface conditions, would be a favored environment for the development and maintenance of thermophilic organisms," they wrote in a report that was published in February's issue of the journal Geology.

More information is available from Rice University's press release.

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Astronomers find first habitable Earth-like planet

Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50 percent larger than the Earth and capable of having liquid water.

This exoplanet - as astronomers call planets around a star other than the Sun – is the smallest ever found up to now and it completes a full orbit in 13 days. It is about five times the mass of the Earth that orbits a red dwarf at a distance about 14 times less than the Earth is from the Sun.

However, as the red dwarf, Gliese 581, is smaller and colder than the Sun – and thus less luminous – scientists speculate that the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid!

"We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid," explains Stéphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result.

"Moreover, its radius should be only 1.5 times the Earth’s radius, and models predict that the planet should be either rocky – like our Earth – or covered with oceans," he adds.

Artist's impression of the system of three planets surrounding the red dwarf Gliese 581 - ESO
"Liquid water is critical to life as we know it," avows Xavier Delfosse, a member of the team from Grenoble University (France). "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."

The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra. It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class.

"Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun," emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method, the most successful in detecting exoplanets.

More information is available from the European Space Observatory’s press release.

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Alien plants might not necessarily be green

Green, yellow or even red-dominant plants may live on extra-solar planets, speculate NASA scientists who believe they have found a way to predict the colour of plants on planets in other solar systems.

The scientists, whose reports appear in the March issue of U.S. journal, Astrobiology, studied light absorbed and reflected by organisms on Earth, and determined that if astronomers were to look at the light given off by planets circling distant stars, they might predict that some planets have mostly non-green plants.

Besides improving our understanding of life on Earth, the findings can potentially improve current methods of searching for life elsewhere in the universe, scientists say.

"We can identify the strongest candidate wavelengths of light for the dominant colour of photosynthesis on another planet," said Nancy Kiang, lead author of the study and a biometeorologist at NASA's Goddard Institute for Space Studies, New York.

Kiang and her colleagues calculated what the stellar light would look like at the surface of Earth-like planets whose atmospheric chemistry is consistent with the different types of stars they orbit. By looking at the changes in that light through different atmospheres, researchers identified colours that would be most favourable on other planets for photosynthesis, which is a process by which plants use energy from sunlight to produce sugar.

In the process of photosynthesis, plants convert energy from the sun into chemical energy in the form of glucose, or sugar - NASA AmesOrganisms that live in different light environments absorb the light colours that are most available. For example, there is a type of bacteria that inhabit murky waters where there is little visible light, and so they use infrared radiation during photosynthesis.

It has long been known that the chlorophyll in most plants on Earth absorbs blue and red light and less green light, so chlorophyll appears green. According to scientists, the Sun has a specific distribution of colours of light, emitting more of some colours than others. Gases in Earth's air also filter sunlight, absorbing different colours. As a result, more red light particles reach Earth's surface than blue or green light particles, so plants use red light for photosynthesis.

But not all stars have the same distribution of light colours as our Sun. Study scientists say they now realize that photosynthesis on extrasolar planets will not necessarily look the same as on Earth. Scientists expect each planet to have different dominant colours for photosynthesis, based on the planet’s atmosphere where the most light reaches the planet’s surface. The dominant photosynthesis might even be in the infrared.

"It makes one appreciate how life on Earth is so intimately adapted to the special qualities of our home planet and Sun," Kiang said.

More information is available from NASA's press release.

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