More inspiring images taken by the Hubble Space Telescope have been released to give us a glimpse of crashing galaxies. To celebrate the telescope's 18th anniversary, the Space Telescope Science Institute unleashed rare pictures of merging galaxies that you don't want to miss. See the article for more details.

Imagine Earth not as the blue and green orb we know today. Imagine it as a psychedelic purple planet. According to microbial geneticist Shil DasSarma from the University of Maryland, ancient purple microbes dominated early Earth.

Today's plants are green because of chlorophyll - the pigment that makes photosynthesis possible. Green leaves absorb the reds and blues in the electromagnetic spectrum (or wavelengths of light) and reflect the greens. The fact is that the sun transmits most of its energy on the greens - so why did today's plants evolve not using the precious green light?

According to DasSarma, the explanation might be simple. There might have been another light-sensitive molecule that takes the green and reflects the reds and blues which causes it to emit a purple color. This ancient light-sensitive molecule was dubbed "retinal" and can be found today in another photosynthetic microbe called halobacteria.

DasSarma speculates that the retinal microbes dominated early Earth (imagine a massive clump of them making a purple spot on the Earth). The chlorophyll using microbes came later and evolved to harness the reds and blues that the retinals did not use since they couldn't complete with the then big boys. So how did chlorophyll become the dominant color? It may have been that the greens were simply more efficient than the purple retinals. According to William Sparks, an astronomer for the Space Telescope Science Institute in Maryland, "Chlorophyll may not sample the peak of the solar spectrum, but it makes better use of the light that it does absorb." DasSarma's theory is still based on speculation but the information fits with what scientists already know. The evidence that shows that retinal developed earlier that chlorophyll:

• Retinal has a simpler molecular structure than chlorophyll, which made it easier to produce in oxygen deprived early Earth
• Retinal production followed a process that resembles that of fatty acid and scientists think that the acid is essential in the development of cells.
• The halobacteria (misnomer since it's not a bacteria but a mibrobe) comes from an ancient group called archaea which dates back to a prehistoric Earth sans the oxygen atmosphere.

The full article awaits after the jump!

The Hubble Space Telescope, Earth's Super Eye in the Sky, has lost the use of its Advanced Camera for Surveys (ACS).  The main cam has been offline since June 19 and managers are scrambling to turn to its other cameras and keep its operations going.

Engineers have not yet identified what caused the ACS to go into a sleep state but they aren't that worried. "We're very optimistic that the camera will be fixed", said Ed Ruitberg, associate program manager for Hubble at NASA's Goddard Space Flight Center.

While this is not the first time the ACS has gone into safe mode the current problem could be more serious requiring more than a standard software reboot. "We're still investigating the problem and working on all sorts of contingencies," said Max Mutchler at the Space Telescope Science Institute in Baltimore. "We're hoping for the best but preparing for other contingencies."

Various solutions have been planned but they can't be implemented until the core problem is known. "Right now we don't know what the core problem is," Mutchler said. Ruitberg thinks the most likely problem is a low-voltage power supply interface. If this is the case, he said it can be easily remedied using redundant electronics to bypass the problem area by June 30.

Size doesn't matter, at least not in Astronomy. Ask astronomer Peter McCullough. Using a "homemade" telescope from commercially available parts, McCullough was able to do what other astronomers with bigger tools could not. He discovered a new planet, X0-1b, the size of Jupiter orbiting a sun-like star 600 light-years away.

"Of the planets that pass in front of their stars, XO-1b is the most similar to Jupiter yet known, and the star XO-1 is the most similar to our Sun," said McCullough, of the Space Telescope Science Institute. "But XO-1b is much, much closer to its star than Jupiter is to the Sun."

Actually, McCullough wasn't alone. He and his team of professional and amateur astronomers have been combing the skies using many telescopes made from relatively inexpensive equipment. The team built their XO prototype telescope, which looks like binoculars, from commercially available 200-millimeter telephoto camera lenses. Mounted on the summit of the Haleakala volcano in Hawaii, the XO prototype telescope cost about $60,000. It may sound expensive but it's a lot cheaper than the many millions of dollars needed to build typical professional observatories. It took McCullough's team three years sifting through tens of thousands of bright stars and culling a few dozen promising candidates. But finally they found X0-1b.

"It was a wonderful feeling because the team had worked for three years to find this one planet," McCullough said. "It's like trying to distill gold out of seawater."