Super-Earths found around sunlike stars

Discoveries raise hopes of finding habitable planets like our own

Four newfound planets orbiting two nearby stars add weight to the promise of detecting habitable worlds within the next few years, researchers said today.

Two of the extrasolar planets are considered super-Earths, more massive than Earth but less massive than Uranus and Neptune. Spotting true Earth-sized planets is challenging with current technology, but the presence of super-Earths suggests finding a world like ours is just a matter of time, researchers say.

"These detections indicate that low-mass planets are quite common around nearby stars," said study team member Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz. "The discovery of potentially habitable nearby worlds may be just a few years away."


The astronomers are not sure if the super-Earths are rocky like our own world or if they have some other composition.

The team found the new planet systems by combining data gathered at the W. M. Keck Observatory in Hawaii and the Anglo-Australian Telescope (AAT) in New South Wales, Australia. They inferred the existence of the planets by noting the worlds' gravitational effects on the parent star's orbit. This method is called the radial velocity, or wobble, technique.

The objects have not been photographed.

Three of the exoplanets orbit the star 61 Virginis, which is virtually a twin of the sun and lies 28 light-years away in the constellation of Virgo. (At this time of year, Virgo can be seen rising a few hours before the sun.)


The researchers estimated the minimum mass of each planet as: 5.1 Earth masses for 61 Vir b, 18 Earth masses for 61 Vir c, and 23 Earth masses for 61 Vir d, according study team member Chris Tinney of the University of New South Wales.

"So the smallest one is in the super-Earth mass range, and is the first planet like this to be found around a sunlike star," Tinney told SPACE.com.

Other super-Earths have been found around stars that are cooler and redder than the sun, he said.

Tinney added, "This is exciting, because it demonstrates the ability of our team to find planets at these interesting, small masses around solar-mass stars. If we want to one day find habitable planets that are really like the Earth in systems that are really like ours, then those are the sorts of stars we need to be able to find low-mass planets around."


The second new system found by the team features a 7.5-Earth-mass planet orbiting HD 1461, another near-perfect twin of the sun located 76 light-years away in the constellation Cetus. The scientists say at least one and possibly two additional planets also orbit the star.

HD 1461 can be seen with the naked eye in the early evening under good dark-sky conditions.

The researchers say they aren't sure whether the planet, now called HD 1461b, is a scaled-up version of Earth, composed largely of rock and iron, or whether, like Uranus and Neptune, it is composed mostly of ices.

India’s lunar mission finds evidence of water on the Moon

Dreams of establishing a manned Moon base could become reality within two decades after India’s first lunar mission found evidence of large quantities of water on its surface.

Data from Chandrayaan-1 also suggests that water is still being formed on the Moon. Scientists said the breakthrough — to be announced by Nasa at a press conference today — would change the face of lunar exploration.



The discovery is a significant boost for India in its space race against China. Dr Mylswamy Annadurai, the mission’s project director at the Indian Space Research Organisation in Bangalore, said: “It’s very satisfying.”

The search for water was one of the mission’s main objectives, but it was a surprise nonetheless, scientists said.The unmanned craft was equipped with Nasa’s Moon Mineralogy Mapper, designed specifically to search for water by picking up the electromagnetic radiation emitted by minerals. The M3 also made the unexpected discovery that water may still be forming on the surface of the Moon, according to scientists familiar with the mission.

“It’s very satisfying,” said Dr Mylswamy Annadurai, the project director of Chandrayaan-1 at the Indian Space Research Organisation (ISRO) in Bangalore. “This was one of the main objectives of Chandrayaan-1, to find evidence of water on the Moon,” he told The Times.

Dr Annadurai would not provide any further details before a news conference at Nasa today from Dr Carle Pieters, a planetary geologist of Brown University who oversaw the M3.

Dr Pieters has not spoken about her results so far and was not available for comment last night, according to colleagues at Brown University. But her results are expected to cause a sensation, and to set the agenda for lunar exploration in the next decade.

They will also provide a significant boost for India as it tries to catch up with China in what many see as a 21st-century space race. “This will create a considerable stir. It was wholly unexpected,” said one scientist also involved in Chandrayaan-1. “People thought that Chandrayaan was just lagging behind the rest but the science that’s coming out, it’s going to be agenda-setting.”

Scientists have long hoped that astronauts could be based on the Moon and use water found there to drink, extract oxygen to breathe and use hydrogen as fuel.

Several studies havesuggested that there could be ice in the craters around the Moon’s poles, but scientists have been unable to confirm the suspicions.

The M3, an imaging spectrometer, was designed to search for water by detecting the electromagnetic radiation given off by different minerals on and just below the surface of the Moon. Unlike previous lunar spectrometers, it was sensitive enough to detect the presence of small amounts of water.

M3 was one of two Nasa instruments among 11 pieces of equipment from around the world on Chandrayaan-1, which was launched into orbit around the Moon in October last year. ISRO lost control of Chandrayaan-1 last month, and aborted the mission ahead of schedule, but not before M3 and the other instruments had beamed data back to Earth.

Another lunar scientist familiar with the findings said: “This is the most exciting breakthrough in at least a decade. And it will probably change the face of lunar exploration for the next decade.”

Scientists are eagerly awaiting the results of two American unmanned lunar missions, which were both launched in June, that could also prove the existence of water on the Moon.

Early results from Nasa’s Lunar Reconnaissance Orbiter (LRO) recorded temperatures as low as -238C (minus 396.4F) in polar craters on the Moon, according to the journal Nature. That makes them the coldest recorded spots in the solar system, even colder than the surface of Pluto, and could mean that ice has been trapped for billions of years, the journal said. The LRO has also detected an abundance of hydrogen, thought to be a key indicator of ice, at the poles.

The other Nasa mission, the Lunar Crater Observation and Sensing Satellite (LCROSS), is due to crash a probe into a polar crater on October 9 in the hope of sending up a plume of ice that can be examined by telescope.

“We are on the verge of a renaissance in our thinking about the poles of the Moon, including how water ice gets there,” Anthony Colaprete, principal investigator for LCROSS, said in Nature.

Big bang

• The Moon is 4.6 billion years old, about the same age as the Earth

• It is thought to have formed from a giant dust cloud caused when a rogue planet collided with the Earth

• It is 238,000 miles from the Earth

• Gravity on the Moon is a sixth of that on Earth

NASA : Hubble Telescope is Back!!

Hubble Telescope is Back: Fantastic New Images Released

NASA's Hubble Space Telescope is back in action after its most recent upgrade, with a spectacular array of new images showing off the telescope's new capabilities.

Among the first images – a closely guarded secret until today – is one of galaxy NGC 6217. The picture was taken with NASA's newly refurbished Advanced Camera for Surveys (ACS).

This is "the day many of us have all been waiting for to celebrate Hubble's new beginning," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at NASA Headquarters in Washington, D.C.

Hubble also snapped pictures of a group of five galaxies, a densely packed star cluster, an eerie "pillar of creation," and a "butterfly" nebula.

Scientists also released spectroscopic observations that slice across billions of light-years to probe the cosmic-web structure of the universe and map the distribution of elements that are fundamental to life as we know it.

Sen. Barbara A. Mikulski, D-Md., who has provided key support for Hubble and NASA in Congress, unveiled the images at NASA Headquarters. She was given the honorary title "Godmother of Hubble." Mikulski's district includes the Space Telescope Science Institute in Baltimore, where Hubble images are processed.

"I fought for the Hubble repair mission because Hubble is the people's telescope," said Mikulski, chairwoman of the Commerce, Justice and Science Appropriations Subcommittee that funds NASA.

Hubble's new instruments, including the Wide Field Camera 3, a new super-sensitive spectrograph, were installed on the 19-year-old telescope by shuttle astronauts during a 13-day service mission in May. The mission, which was initially cancelled in 2004 due to safety concerns after the 2003 Columbia shuttle disaster, also revived two instruments — Hubble's main ACS and a versatile imaging spectrograph — that were never designed to be fixed in space.

The new instruments are more sensitive to light and, therefore, will improve Hubble's observing efficiency significantly. It is able to complete observations in a fraction of the time that was needed with prior generations of Hubble instruments.

The WFC3 was actually used to take a picture of Jupiter's new black spot — thought to have been caused by a comet collision — back in July, but the camera wasn't yet fully calibrated then. WFC3 also took new images of the Omega Centauri star cluster in our galaxy, in which the contrast between hot and cool stars can vividly be seen, and the Butterfly Nebula, for which astronomers used the new filters on the camera to see the envelope of gas expanding away from this planetary nebula.

"We couldn't be happier about the way things have gone," Bob O'Connell, chair of the science oversight committee for the Wide Field Camera 3 at the University of Virginia. "We're fully confident the camera is working as it was intended to work."

Images taken with the new Cosmic Origins Spectrograph were taken in one-tenth of the time of Hubble's older spectrograph, which will allow scientists to view 10 times as many targets or look at targets one-tenth as bright, said James Green, the COS principal investigator at the University of Colorado. Scientists hope to build a catalogue of hundreds or thousands of targets and map the distribution of matter throughout the universe.

Hubble will also be able to continue observations of Eta Carinae, one of the most massive stars in the galaxy (and actually a pair of stars), that were suspended by instrument failure in 2004, said David Leckrone, senior project scientist for Hubble at NASA's Goddard Space Flight Center in Greenbelt, Md. Eta Carinae has erupted before and is expected to do so again.

Despite a few bumps in the three-month checkout, Hubble's systems and instruments are all up and running now.

NASA's new administrator Charlie Bolden was also on hand to congratulate the scientists and astronauts on Hubble's new lease on life. Bolden was one of the astronauts on the shuttle mission that deployed Hubble in 1990.

"Hubble has a special place in my heart," Bolden said. Through Hubble's past and future observations, "our view of the universe and our place within it will never be the same," he added.