One very elegant way of travelling inside the Solar System is by using a Solar Sail. In such a system, the spacecraft unfurls a large, lightweight sail which reflects light from the Sun or some other source. The radiation pressure on the sail provides thrust by absorbing (for black sail) or reflecting (for reflective sail) photons. In one my previous posts, I talked about a NASA experiment to test a solar sail in a vacuum chamber that will simulate the space environment. Now a more ambitious proposal by The Planetary Society and the Cosmos Studios plans to test a concept Solar Sail (named Cosmos 1) in space within the next few weeks :).

Cosmos 1 (Courtesy: The Planetary Society)The most amazing thing about this project is that it is not funded by any government! Cosmos 1 has 8 triangular sails, each 15 meters (50 feet) in length, configured around the spacecraft's body at the center. The sails will be deployed by inflatable tubes once the spacecraft is in orbit. The spacecraft will be launched from a submerged Russian submarine in the Barents Sea. It will be carried into orbit on board a Volna rocket - a converted ICBM left over from the old Soviet arsenal.
Cosmos 1 will orbit the Earth at an altitude of over 800 kilometers. It will gradually raise its orbit by solar sailing -- the pressure of light particles from the Sun upon its luminous sails. According to the Planetary Society, the launch will take place sometime before May 30 this year.
Perhaps some day, we will see Solar sails transporting supplies between space-stations and planetary bases across our Solar System :):). Hopefully, in our lifetime....

Almost every elevator in use today consists of an elaborate contraption of gears, pulleys and shock absorbers. Not only such elevators are bulky and hard to install, they are also more prone to breakdowns. Scientists from Daytona Elevators, a company based in Argentina and Florida, have finally developed a elevator worthy of the 21st century. The elevator (for one person use) is a metre in diameter and almost entirely transparent, providing the passengers with a panoramic view during their ride. Made from lightweight Aluminium and polycarbonate, the installation is a breeze.

Vacuum Elevator (Courtesy: Daytona Elevator)The working principle is very simple. A piston depressurizes the region above the passenger capsule. The capsule is then lifted by the higher atmospheric pressure at the bottom (not unlike the way a aircraft wing lifts the plane up during flight). While coming down, a valve at the top regulates the air pressure to allow a smooth descent. A braking system ensures smooth stopping of the capsule in case of pressure malfunctions.
The elevator costs between $20,000 and $22,000. It is silent, consumes very little power, and can be installed in small spaces. A video of its operation can be found here (MPEG 3.2MB).

After the formation of the Sun and the planets from a interstellar cloud of gas, the matter that was left behind coalesced into the asteroids, meteors, and comets, and a halo of rocks beyond the orbit of Neptune (50AU from Sun), collectively known as the Kuiper Belt. Scientists have long suspected that a occasional nudge or gravitational instability (due to a passing star, or attraction by the larger planets such as Neptune and Uranus) could and should push one or more of these rocks towards the Sun. These rocks then end up as meteors, only to crash into the Sun or planets, or get captured as a moon of a large planet.

Phoebe (Courtesy: NASA)Recent observations by the Cassini craft orbiting the Saturnian system have now confirmed that the moon Phoebe was once a member of the Kuiper Belt. Such inward motion by Kuiper-Belt objects have been theorized before. Most notably, it is possible that the meteorite that helped kill off the dinosaurs some 65 million years ago, was indeed such an object. Similarly, an ancient interaction with Saturn left the moon Phoebe as its prisoner. Before Cassini flew by the moon, little if anything was known about it. During the encounter, scientists got the first detailed look at Phoebe, which allowed them to determine its makeup and mass. With the new information they have concluded that it has an outer solar system origin, like Pluto and other Kuiper Belt objects.
It seems that Phoebe has a totally different ratio of rock and ice, as compared to other Saturnian moons. Its density is about 1.6 g/cc, much lighter than most rocks but heavier than pure ice, which is about 0.93 g/cc. This suggests a composition of ice and rock similar to that of Pluto and Neptune's moon Triton. Whether Saturn's other moons are also prisoners from the Kuiper's Belt remains to be seen.

The processes that created our Solar System are quite well understood. About 4.56 billion years ago, plumes of gas ejected by a local supernova (as well as ejecta from other stars, and interstellar materials) started collapsing under its own gravitational force. The central region of the collapsing gas grew larger, and slowly an accretion disk formed around it. After a few million years, the central region got so dense that nuclear fusion started at its core: we had the birth of our Sun. The accretion disk slowly coalesced into the planets and asteroids, and the left over material formed comets and meteors. Now for the first time, scientists have precisely dated the age of this seminal event, and how long it took the gases to coalesce into the Sun and planets.

Allende Meteorite (Courtesy: LLNL)Chondrules are small silicate spheres in many meteorites, and represent the oldest solid material within our solar system and are believed to be the building blocks of the planetary system. Another common component of meteorites are the Calcium Aluminium-rich inclusions (CAIs). By looking at the content of these two in the primitive meteorite Allende (fell on Mexico in 1869), Lawrence Livermore Lab physicist Ian Hutcheon, with colleagues from the University of Hawaii at Manoa, the Tokyo Institute of Technology and the Smithsonian Institution, found that the age difference between them points directly to the lifetime of the solar nebula.
The researchers found that CAIs were formed in an oxygen-rich environment and date to 4.567 billion years old, while chondrules were formed in an oxygen setting much like that on Earth and date to 4.565 billion, or less, years old. Therefore, it took about 2 million years for the solar nebula to coalesce, and form the Sun and planets, including Earth :):). Also, the age of the Earth is therefore quite precisely fixed at between 4.565 and 4.567 billion years! :D.

In this age of global warming and pollution, it is imperative that we find cleaner sources of energy. Some alternatives, such as hydrogen-powered fuel cells are quite appealing, since the exhaust from such cells is pure water. However, Hydrogen, being a gas, occupies a large volume, and this is hampering any real development in this area. Now researchers from National Institute of Science and Technology (Taner Yildirim) and Turkey's Bilkent University (Salim Ciraci) have developed a new model for a metal-laced Carbon Nano-tube, which can latch on to hydrogen molecules in numbers more than adequate for efficient hydrogen storage, a capability key to long-term efforts to develop fuel cells.

Model: Titanium-Blue, Hydrogen-Red (Courtesy: NIST)Carbon nanotubes are tubes composed entirely of carbon atoms, and often composed of a chain of carbon rings (picture here). Calculations by the researchers show that if decorated with Titanium or other transition metals, such tubes can attract Hydrogen atoms, which get attached to the Titanium atoms. The total weight of Hydrogen can be upto 8% of the weight of the tubes, which exceeds the standard of 6% specified by the FreedomCar Research Partnership involving the US Department of Energy and USA's "Big 3" automakers. Moreover, if heated, the Titanium atoms readily give up four attached Hydrogen atoms! Such reversible desorption is another requirement for practical Hydrogen storage.
The new results, obtained with a method for calculating the electronic structure of materials, surprised the researchers. Interactions among Carbon, Titanium and Hydrogen seem to give rise to unusual attractive forces. The upshot is that four Hydrogen molecules can dock on a Titanium atom, apparently by means of a unique chemical bond of modest strength. Several forces at work within the geometric arrangement appear to play a role in the reversible tethering of Hydrogen.
The results are the first glimmer of hope in sustainable storage of Hydrogen in mass quantities. If developed, this technology should allow vehicles to have a nanotube-based fuel tank, capable of storing large quantities of Hydrogen in a small enough volume to be of practical use :).

Mars Express, so called because of the rapid and streamlined development time, represents ESA's first visit to another planet in the Solar System. Already this spacecraft has advanced our knowledge of the red planet, through numerous high resolution pictures. The Mars Express has several instruments on-board (High Resolution Stereo Camera, OMEGA Visible and Infrared Mineralogical Mapping Spectrometer, MARSIS Sub-Surface Sounding Radar Altimeter, among others). Now after a series of delays, the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) is finally ready to be deployed, which will look for the presence of water upto a few kilometers under the surface of Mars.

MARSIS searching water (Courtesy: JPL)MARSIS instrument consists of three long fibreglass tubes strung with wires that will bounce radio waves off the planet. Some waves will penetrate the surface – potentially revealing oases of water, in liquid or ice form. In the first few months of the experiment, Mars Express will pass over an equatorial region that some scientists suggest harbours a frozen sea just beneath the surface.
A successful find has huge consequences. It will dramatically increase the chances of success of any future human mission to Mars. Also, presence of water will significally boost the possibility of life on Mars :):).

Many organisms have the innate capability to regenerate lost body parts. Plants do it all the time, and animals such as salamanders can regenerate a missing tail, legs, even eyes! Among invertebrates (sponges, Hydra, Starfish) it is more common, and it gets less and less common as we move up the complexity scale. Why and how it happens, and why it is rare in higher animals, is still a mystery. One fundamental quest is to find the genes that control this process of regeneration. Now University of Utah researchers have successfully identified many such genes in a flatworm, called Planarian (Schmidtea mediterranea). Interestingly, it shares many of genes with us humans (Yay evolution :) ), and therefore this work can uncover clues to our abilities to regenerate :D.

Planarian (Courtesy: John Burroughs School)Planarians have a great ability to regenerate. Chop one in half, and two new worms grow. Their ability to regenerate is so prolific that a tissue fragment only 1/279th of the worm’s length can grow into a new planarian. Planarian stem cells, called neoblasts, play a central role in this process. But this process was shrouded in mystery, until now.
Sánchez Alvarado and Peter W. Reddien first inserted RNA strands that shut off a particular planarian gene into some bacterial DNA. Next, they fed such bacteria-laced food to the planarian. Predictably enough, soon the planarian genome was riddled with this RNA, which effectively shut down the expression of this particular planarian gene. By repeating the process with different RNA strands that shut off different planarian genes, the researchers were able to map the behavior of the genes by observing the defects they introduce in the planarian 'children'.
The researchers found that out of 1,065 planarian genes, 145 affect both regeneration and tissue loss and replacement. 38 of these genes are related to human genes associated with diseases, such as ataxia (inability to coordinate muscular movements), bradyopsia (slow vision), and cancer!! This makes the planarian an ideal model to test human diseases, and perhaps to find a cure for the various ailments that affect us.
Scientists should now be able to shut off genes in planarian, and tinker with them to see how genetic expression in planarian contribute to its regenerative capabilities. This can lead to new treatments to terrible diseases in the not too distant future :):).