GENERAL SCIENCE NEWS

INDIAN SPACECRAFT FINDS WATER ON THE MOON

[NEWS.com.au, September 24, 2009]

The discovery of water by a lunar mission has led to greater hope of humans colonising the moon. India's first lunar mission has found evidence of large quantities of water on its surface, The Times newspaper said. Data from the Chandrayaan-1 spacecraft also suggested water was still being formed on the moon, the British newspaper said.

"It's very satisfying," the newspaper quoted Mylswamy Annadurai, the mission's project director at the Indian Space Research Organization in Bangalore, as saying. The discovery has opened the door for possible moon bases being established, with astronauts taking advantage of the water on the surface. After further analysis is done, the next task for scientists will be to figure out how to exploit the water to move towards an international lunar base, director of the International Lunar Exploration Working Group Bernard Foing told MSNBC.

The discovery is also expected to significantly boost India's race to catch up with other nation's space exploration efforts. “This will create a considerable stir. It was wholly unexpected,” said one scientist also involved in the mission. “People thought that Chandrayaan was just lagging behind the rest but the science that’s coming out, it’s going to be agenda-setting.”

The discovery has also made scientists excited about future moon missions. "Within the context of lunar science, this is a major discovery," planetary scientist Paul G. Lucey, a planetary scientist told the LA Times. "There was zero accepted evidence that there was any water at the lunar surface, (but) now it is shown to be easily detectable, though by extremely sensitive methods. As a lunar scientist, when I read about this I was completely blown away."

The Times said the breakthrough would be announced by the US National Aeronautic Space Agency later today. NASA's website says it will hold a media briefing to "reveal new scientific findings about the moon" from data collected during national and international space missions." The unmanned Indian craft was equipped with NASA's Moon Mineralogy Mapper.

EARTH-LIKE PANETS MAY BE VERY COMMON

[Reuters, June 16, 2008]

Researchers today said they discovered a batch of three "super-Earths" orbiting a nearby star, and two other solar systems with small planets as well. They said their findings, presented at a conference in France, suggest that Earth-like planets may be very common.

"Does every single star harbour planets and, if yes, how many?" asked Michel Mayor of Switzerland's Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it," Mr Mayor said in a statement.

The trio of planets orbit a star slightly less massive than our Sun, 42 light-years away towards the southern Doradus and Pictor constellations. A light-year is the distance light can travel in one year at a speed of 300,000km per second -- or about 9.5 trillion kilometres. The planets are bigger than Earth -- one is 4.2 times the mass, one is 6.7 times and the third is 9.4 times. They orbit their star at extremely rapid speeds -- one whizzing around in just four days, compared with Earth's 365 days, one taking 10 days and the slowest taking 20 days.

Mayor and colleagues used the High Accuracy Radial velocity Planet Searcher or HARPS, a telescope at La Silla observatory in Chile, to find the planets. More than 270 so-called exoplanets have been found. Most are giants, resembling Jupiter or Saturn. Smaller planets closer to the size of Earth are far more difficult to spot. None can be imaged directly at such distances but can be spotted indirectly using radio waves or, in the case of HARPS, spectrographic measurements. As a planet orbits, it makes the star wobble very slightly and this can be measured.

"With the advent of much more precise instruments such as the HARPS spectrograph ... we can now discover smaller planets, with masses between 2 and 10 times the Earth's mass," said Stephane Udry, who also worked on the study. The team also said they found a planet 7.5 times the mass of Earth orbiting the star HD 181433 in 9.5 days. This star also has a Jupiter-like planet that orbits every three years. Another solar system has a planet 22 times the mass of Earth, orbiting every four days, and a Saturn-like planet with a three-year period.

"Clearly these planets are only the tip of the iceberg," said Mr Mayor. "The analysis of all the stars studied with HARPS shows that about one third of all solar-like stars have either super-Earth or Neptune-like planets with orbital periods shorter than 50 days."

AUSSIE SCIENTIST AWARDED FOR COSMOLOGY DISCOVERY

[Australian Associated Press, July 17, 2007]

An Australian astronomer has been honoured with a top international science prize for finding evidence of a mysterious force causing the universe to expand at an ever-increasing rate. Australian National University professor Brian Schmidt's discovery shocked the physics community when it was published in 1998. But the idea is now widely accepted, leading to the researcher and his team being awarded the prestigious and lucrative Gruber Prize for Cosmology, the branch of astronomy that deals with the origin, evolution and general structure of the universe. "When I made this discovery it was hard to believe," Prof Schmidt said. "I think it's pretty much consensus now that what we saw in the field was real -- as crazy as it seems."

The researchers used the Hubble Space Telescope and ground-based telescopes in Australia, Hawaii and Chile to analyse the light arriving from 14 supernovae, or exploding stars, that were seven billion to 10 billion light years from earth. They measured the speed at which the stars were moving away by repeatedly observing the objects and analysing how their motion stretched the light. This rate was then compared with the motion of supernovae much closer to the earth.

The team expected to find the expansion of the universe was slowing slightly from the effect of gravity, which was the recognised theory at the time. Instead, they found the expansion of the universe was accelerating, which they attributed to a "hidden dark energy" -- first suggested by Albert Einstein -- thought to make up more than 70 per cent of the universe. "You only get to discover 70 per cent of the universe once," Prof Schmidt said. But he said scientists still had "no clue" what the energy was, despite thousands around the world trying to figure it out. "It's easy to make the universe slow down, gravity does that, but to make it speed up, that's pretty remarkable -- that defies physics as we know it," he said.

One theory is that gravity may work in reverse on the energy, repulsing it rather than attracting it. Prof Schmidt, an Alaskan-born Australian citizen, and his research team will go to Cambridge to accept their prize in September along with a University of California researcher. He has previously won the Harvard Bok Prize, the inaugural Malcolm McIntosh Award, and the Shaw Prize in Astronomy. Prof Schmidt is now heading the five-year Southern Sky Survey, which will begin next year and aims to capture the most sensitive map yet of the southern hemisphere sky using the Skymapper telescope.

The telescope will be shipped to the Siding Spring Observatory near Coonabarabran from the US later this year. "We'll be able to see the universe in six colours right back 12.8 billion years, about 850 million years after it formed (in the Big Bang)," Prof Schmidt said. The Gruber Prize is sponsored by the US-based Gruber Foundation and the International Astronomy Union.

Visit Brian Schmidt’s Home Page

LOOKING FOR ALIEN LIFE IN THE WRONG PLACES

[Sunday Mail, July 08, 2007]

Extraterrestrial life may well be so weird we would not immediately recognise it, space experts said yesterday. Scientists looking for alien life should be seeking the unfamiliar as well as the familiar, they said. NASA's current approach to "follow the water" is logical assuming alien life is comparable to that on Earth -- based on water, carbon and DNA -- but the "life as we know it" approach could easily miss something exotic, the US National Academy of Sciences panel advised.

"The purpose of this whole report was to be able to look for life on other planets and moons with an open mind ... and not maybe miss some other life form because we are looking for some obvious life form," said John Baross, professor of oceanography at the University of Washington in Seattle, who chaired the committee. The US space agency commissioned the report from the National Research Council.

The panel of biochemists, planetary scientists, geneticists and other experts considered all possible ways life can arise and exist. Recent discoveries of extremophiles -- organisms living in conditions of heat, cold and dark and using chemicals once thought incompatible with life -- have changed ideas of where life can survive. Prof Baross said lab experiments also showed water did not necessarily have to be the basis for life. It might be possible for a living organism to use methane, ethane, ammonia or even more bizarre chemicals.

"We had some discussion about how weird to make this because there are so many concepts out here. There are so many theories about what life is and what could be a living system."

NASA and other groups are looking hard for extraterrestrial life. Telescopes search for spectral signatures from other planets that might suggest water is on the surface. Robots on Mars are seeking evidence of water, past or present. "We wanted to actually think outside of that box a little bit and at least try to articulate some of the other possibilities besides water-carbon life."

They suggested NASA should return to some of the more promising places in our own solar system to look for evidence of life, such as Saturn's moons Titan and Enceladus, and even steamy Venus.

RUSSIAN COSMONAUTS DON'T LIKE COMING HOME

[Reuters, Russia, May 10, 2007]

Given the choice, Russian cosmonauts would likely never come back to Earth. It is the part of their jobs they like the least. "The best, the most beautiful part, is after the start when you look at Earth straight away," Cosmonaut Vladimir Dezhurov said.

"Earth is like a big, blue balloon and this beautiful balloon is flying, all around it is solid blackness."

Dezhurov has lived in Star City – a formerly top-secret training base for cosmonauts near Moscow – for 21 years and has done two four-month stints aboard the International Space Station, 350 km above Earth. He can think of no other profession he'd like better, despite the fact that after the launch, and that glimpse of his home planet, "it's all work, work, work up there, night and day."

But his main gripe is not the long hours, or missing his family and friends. "The hardest thing is coming back to Earth," he said. The problem is not so much the mundanity of earthly existence – bills to pay, food to buy, chores to complete. The muscle fabric degrades very much. It's hard to walk. You have to learn how to walk again, like a small child."

Astronauts train daily aboard the orbiting space station to prevent the atrophy of their legs and feet which are under-used in weightlessness. It takes several weeks under medical supervision to recover from a long stay in space.

Star City is a grey, Soviet-era town of around 5,000. Most of its 1960s buildings need a facelift – bar some pretty white cottages built by NASA for its astronauts. Access to the town is highly restricted. Behind big, empty lobbies decorated with Soviet-style artworks and dark corridors are training rooms and offices packed with old-looking, grubby equipment – yet they hide some of the world's most complex and reliable electronic systems.

The impression that time has stopped in Star City is not entirely superficial. Dezhurov says cosmonauts have not experienced any drastic changes after the collapse of the Soviet Union in 1991. "It did not have much of an impact on our work. The financing carried on, maybe it decreased a little, but we always worked," he said.

Russian cosmonauts, who are either military pilots or engineers or doctors by training, also have to prepare for the physical strains of travelling inside a cramped rocket and living in zero gravity. They experience weightlessness inside special airplanes that fly sharply up and down in a parabola generating a centrifugal pull which is equal to gravity and so cancels it out.

"It is different from any previous experiences a person might have had," the world's fifth space tourist Charles Simonyi wrote in his blog after a parabolic flight exercise in February. In another drill, a giant centrifuge simulates the gravitational pull on a space traveller during launch and re-entry, about 4Gs, which means a cosmonaut feels four times heavier.

Those with a spare $US 25 million ($AU 30.35 million) to spend can go through the training and then apply it in practice as a visitor to the space station.

Simonyi, 58, a former Microsoft software executive, returned to Earth safely on April 21 after a two-week trip. Chris Faranetta, a senior executive at the travel agency that arranged Simonyi's flight, said of sending private visitors closer to the stars: "It's about understanding who we are and where we are from. We are made of star dust, all of us." But some cosmonauts are in two minds about space tourism.

"On the one hand, when a guy comes along with a big sack of money and flies into space while other Earth dwellers can't do that ... of course, it isn't good," cosmonaut Gennady Padalka said. "But it's good financial support."

Professional astronaut or space tourist, one thing's for sure – they'll come back down to Earth with a bump.

DNA RESEARCH SUGGESTS FIRST AUSTRALIANS CAME FROM AFRICA

[AAP, May 08, 2007]

Australia and the rest of the world was first settled by a single group of people who migrated from Africa more than 55,000 years ago, DNA research suggests.

A study of DNA samples from Aboriginal Australians and Melanesians from New Guinea, led by Peter Forster at Britain's University of Cambridge, appears to verify the theory that all humans came from the same small group of Africans.

The Australian and New Guinean populations were found to share genetic features linking them those who left Africa up to 60,000 years ago.

"Although it has been speculated that the populations of Australia and New Guinea came from the same ancestors, the fossil record differs so significantly it has been difficult to prove," Dr Forster told Britain's The Times newspaper. "For the first time, this evidence gives us a genetic link showing that the Australian Aboriginal and New Guinean populations are descended directly from the same specific group of people who emerged from the African migration."

Dr Forster, who is now at the Anglia Ruskin University, said the ancient Australians would have travelled from Africa via Arabia, Asia and the Malay peninsula, dispersing at a rate of about 1km per year. The uniqueness of Australia's ancient Aborigines and archaeological finds in the country previously threatened to undermine the theory that humans are all descended from the same group.

Critics of the theory believe modern human beings may have evolved in several different places, arisen through interbreeding, or made several trips out of Africa. They cited as evidence the fact skeletal and tool remains found in Australia are strikingly different from those on the "coastal expressway" the early settlers are supposed to have taken through south Asia.

HOT ICE PLANET FOUND 33 LIGHT YEARS FROM EARTH

[Los Angeles Times, May 18, 2007]

European astronomers think they have found a hot snowball orbiting a star about 33 light years from Earth. The strange planet, called GJ 436b, is about the size of Neptune. It orbits a red dwarf star, about half the mass of the sun but 100 times as dim. The cool temperature of the star is a main reason that water can persist on the planet's surface, research published this week in the journal Astronomy & Astrophysics says.

The planet "turns out to be a Neptune-like ice giant, mostly composed of water ice," the authors wrote. The team made its findings using telescopes in Switzerland, Israel and Chile. "It's not a very welcoming planet," said Dr Frederic Pont, an astronomer at the Geneva Observatory, who helped make the discovery. "The water is frozen by the pressure, but it's hot. It's a bit strange … but in fact water can be solidified by pressure."

The planet was first discovered in 2004 by a team of US researchers led by Professor Geoff Marcy of the University of California, Berkeley. It is one of more than 200 planets orbiting other stars that have been discovered in recent years. Most were found by analysing the motions of their host stars. Although the planets are too far away to be seen directly, their existence can be inferred by the way their gravity tugs on their host stars, making them wobble.

The weakness of this technique is that it turns up planets in very close orbits, which by their nature are too hot to support life.

GJ 436b has one of the tightest orbits of these so-called exoplanets, circling its star every three days. So even though the star is relatively cool, the planet's surface is hot, estimated at about 247 degrees. The key to the discovery that GJ 436b could be an ocean planet was its density. Researchers first determined the planet's size by watching it pass in front of its star, causing a kind of mini-eclipse. "The mass and radius that we measure for GJ 436b indicate that it is mainly composed of water ice," the researchers said.

The planet could have an atmosphere of hydrogen and helium, and a rock-iron core, like Earth. Large amounts of methane, which also shrouds Saturn's giant moon, Titan, could be present. Combined with the scorching heat, that would make the planet hostile to life as we know it. However, if the planet is covered in water, it makes finding other planets with water in more hospitable orbital zones more likely.