Wednesday, July 28, 2010

Force Fields Could Protect Mars Missions

NASA is nervous about sending astronauts to Mars -- and understandably so. Six months' exposure to the wind of high-energy particles streaming from the sun could indeed prove deadly. But a team of researchers at the Rutherford Appleton Laboratory (RAL) near Oxford, UK, has hit upon a phenomenon that might just solve the problem.

They have shown that a magnet no wider than your thumb can deflect a stream of charged particles like those in the solar wind. It gives new life to an old idea about shielding spacecraft, and might just usher in a new era of space travel. "Space radiation has been called the only showstopper for the crewed exploration of space," says Ruth Bamford of RAL. "Our experiment demonstrates there may be a way the show can go on."

Tuesday, July 27, 2010

Aging Spacecraft Makes Best-Ever Map of Mars

The oldest spacecraft now operating around Mars has produced the best ever map of the Red Planet. NASA's Mars Odyssey reached the planet in 2001 and researchers have now stitched together 21,000 of its images into a global map.

When seen as a whole, the gray-scale map isn't much to look at, but its power snaps into focus when viewers zoom in on particular features, whose details can be seen at scales as small as 100 metres across - see a 140-km-wide image of Mars's "Grand Canyon" below. (Cameras such as HiRISE on the newer Mars Reconnaissance Orbiter can spot things about 1 metre wide, but have covered only small portions of the planet.)

Asteroid Might Collide With Earth in 2182

The potentially hazardous asteroid (101955) 1999 RQ36 has a one-in-a-thousand chance of impacting the Earth, and more than half of this probability indicates that this could happen in the year 2182, based on a global study in which Spanish researchers have been involved. Knowing this fact may help design in advance mechanisms aimed at deviating the asteroid's path.

"The total impact probability of asteroid (101955) 1999 RQ36 can be estimated in 0.00092 -- approximately one-in-a-thousand chance -- but what is most surprising is that over half of this chance (0.00054) corresponds to 2182," explains María Eugenia Sansaturio, co-author of the study and researcher of Universidad de Valladolid (UVA).

Friday, July 23, 2010

"Fresh" Meteorite Crater Found in Egypt

One of the best preserved craters yet found on Earth, the Egyptian Kamil crater was initially discovered in February during a survey of satellite images on Google Earth. Researchers think the crater formed within the past couple thousand years.

The Italian-Egyptian team that found the crater in pictures recently visited and studied the 147-foot-wide, 52-foot-deep hole. The team also collected thousands of pieces of the space rock that littered the surrounding desert. Based on their calculations, the team thinks that a 4.2-foot-wide solid iron meteor weighing 11,023 to 22,046 pounds smashed into the desert—nearly intact—at speeds exceeding 2.1 miles a second.

Wednesday, July 21, 2010

Cometary Impact on Neptune Two Centuries Ago

A comet may have hit the planet Neptune about two centuries ago. This is indicated by the distribution of carbon monoxide in the atmosphere of the gas giant that researchers have now studied. The scientists analyzed data taken by the research satellite Herschel, that has been orbiting the Sun in a distance of approximately 1.5 million kilometers since May 2009.

When the comet Shoemaker-Levy 9 hit Jupiter sixteen years ago, scientists all over the world were prepared: instruments on board the space probes Voyager 2, Galileo and Ulysses documented every detail of this rare incident. Today, this data helps scientists detect cometary impacts that happened many, many years ago. The "dusty snowballs" leave traces in the atmosphere of the gas giants: water, carbon dioxide, carbon monoxide, hydrocyanic acid, and carbon sulfide. These molecules can be detected in the radiation the planet radiates into space.

Scientists Find Most Massive Star Ever

A huge ball of brightly burning gas drifting through a neighboring galaxy may be the heaviest star ever discovered — hundreds of times more massive than the sun, scientists said Wednesday after working out its weight for the first time.

Those behind the find say the star, called R136a1, may once have weighed as much as 320 solar masses. Astrophysicist Paul Crowther said the obese star — twice as heavy as any previously discovered — has already slimmed down considerably over its lifetime. Crowther said the giant was identified at the center of a star cluster in the Tarantula Nebula, a sprawling cloud of gas and dust in the Large Magellanic Cloud, a galaxy about 165,000 light-years away from our own Milky Way.

Friday, July 16, 2010

Mercury Flyby Reveals Magnetic "Power Surges"

New data from the third and final flyby of the MESSENGER spacecraft have revealed surprisingly intense electromagnetic storms in Mercury's magnetic "tail," part of the planet's magnetic field. Such tails form when the solar wind—charged particles streaming from the sun—pushes on a planet's magnetic field.

During a September 29, 2009, flyby of the tiny planet, MESSENGER watched as Mercury's magnetic tail collected enormous amounts of energy from the solar wind. In just 90 seconds, the tail increased magnetic field power by 200 percent during an event known as a magnetic substorm. The tail then snapped back to normal, dissipating the energy over the next minute and a half.

25,000 New Asteroids Found by WISE

One of NASA's newest space telescopes has spotted 25,000 never-before-seen asteroids in just six months. Ninety-five of those are considered "near Earth," but in the language of astronomy that means within 30 million miles. Luckily for us, none poses any threat to Earth anytime soon.

Called WISE for Wide-field Infrared Survey Explorer, the telescope completes its first full scan of the sky on Saturday and then begins another round of imaging.

Thursday, July 15, 2010

Ultrabright Gamma-ray Burst "Blinded" Swift

A flash of light that likely signaled the birth of a black hole was so bright it briefly blinded a NASA telescope—even though the light came from five billion light-years away. From its orbit around Earth, the Swift telescope has been scanning the skies since 2004 for mysterious, ultrabright flashes known as gamma-ray bursts.

Swift was designed to look for these bright events and study the initial flash of gamma rays and high-energy x-rays as well as the "afterglow" of lower-energy x-rays and ultraviolet light. Even though it can’t scan the whole sky at once, the telescope typically finds about two gamma-ray bursts a week. But on June 21 a rush of light from a minute-long gamma-ray burst proved so overwhelming that Swift’s data processing software temporarily shut down.

Planet With Unique Comet-Like Tail Discovered

Astronomers using NASA's Hubble Space Telescope have confirmed the existence of a baked object that could be called a "cometary planet." The gas giant planet, named HD 209458b, is orbiting so close to its star that its heated atmosphere is escaping into space.

Observations taken with Hubble's Cosmic Origins Spectrograph (COS) suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched planet and shaping it into a comet-like tail

Monday, July 12, 2010

Rosetta probe passes Asteroid Lutetia

Europe's Rosetta space probe has flown past the Asteroid Lutetia, returning a stream of scientific data for analysis. The rock - some 120km (75 miles) in its longest dimension - is the biggest asteroid yet visited by a satellite.

Pictures showed Lutetia to be quite irregular in shape, its surface marked by a number of wide impact craters and even some intriguing grooves. Rosetta's encounter with the asteroid occurred some 454 million km from Earth, beyond the orbit of Mars.

Saturday, July 10, 2010

Total Solar Eclipse of 2010 July 11

On Sunday, 2010 July 11, a total eclipse of the Sun is visible from within a narrow corridor that traverses Earth's southern Hemisphere. The path of the Moon's umbral shadow crosses the South Pacific Ocean where it makes no landfall except for Mangaia (Cook Islands) and Easter Island (Isla de Pascua).

The path of totality ends just after reaching southern Chile and Argentina. The Moon's penumbral shadow produces a partial eclipse visible from a much larger region covering the South Pacific and southern South America

Friday, July 9, 2010

Brand New Planet-Finding Technique

A team of astronomers from Germany, Bulgaria and Poland have used a completely new technique to find an exotic extrasolar planet. The same approach is sensitive enough to find planets as small as the Earth in orbit around other stars. The group, led by Dr Gracjan Maciejewski of Jena University in Germany, used Transit Timing Variation to detect a planet with 15 times the mass of the Earth in the system WASP-3, 700 light years from the Sun in the constellation of Lyra.

The TTV method is very attractive, because it is particularly sensitive to small perturbing planets, even down to the mass of the Earth. For example, an Earth-mass planet will pull on a typical gas giant planet orbiting close to its star and cause deviations in the timing of the larger objects' transits of up to 1 minute.

Tuesday, July 6, 2010

Planck's First Hi-Res Image

Researchers on the Planck telescope, the biggest cosmology experiment in nearly a decade, have released their first full sky map of the cosmic microwave background.

The image shows the Milky Way as a bright, horizontal band through the centre with "streamers" of cold dust extending above and below. But the interesting part to researchers is the scattering of yellow flecks in the red background. These oldest photons in the universe are thought to have been generated about 380,000 years after the Big Bang, when matter was finally cool enough to start forming atoms.

Watch While an Asteroid Eats a Star

In a rare event on July 8, 2010, skywatchers will be able to see an asteroid briefly block out the light from a star as it passes in front. It may be the only asteroid "occultation" this century observable with the naked eye.

During the night of 8/9 July, however, a star that is visible to the naked eye, Delta Ophiuchi (the fourth-brightest star in the constellation Ophiuchi), will be occulted by asteroid Roma, which has a diameter of about 50 km.

Thursday, July 1, 2010

Space Station Visible All Night Tonight

The International Space Station (ISS) has entered the "twilight zone," giving sky-watchers in select places around the world unprecedented multiple views of the orbiting facility tonight.

The space station isn't always visible at night when it passes overhead, because it spends about 30 percent of its time cloaked by Earth's shadow. But once a year the high-flying facility's orbit closely parallels what's known as the day-night terminator, the zone of perpetual twilight on the border between Earth's dayside and nightside. When it's in the zone, the ISS can be seen with the naked eye every time it passes overhead, from dusk til dawn.

Last Shuttle Flight Delayed until 2011

NASA made it official Thursday after weeks of hints of launch delays: More time is needed to get the cargo ready for the final two shuttle flights. What's more, a decision regarding a possible third — and really last — mission is off until at least next month.

Managers agreed to postpone the next-to-last shuttle launch until Nov. 1. Discovery had been scheduled to fly to the International Space Station with a load of supplies in September. The very last mission now has a Feb. 26, 2011, launch date. Endeavour will close out the 30-year shuttle program by delivering a major scientific instrument to the space station.

First Directly Imaged Planet Confirmed

A planet only about eight times the mass of Jupiter has been confirmed orbiting a Sun-like star at over 300 times farther from the star than the Earth is from our Sun. The newly confirmed planet is the least massive planet known to orbit at such a great distance from its host star. The discovery utilized high-resolution adaptive optics technology at the Gemini Observatory to take direct images and spectra of the planet.

First reported in September 2008 by a team led by David Lafrenière (then at the University of Toronto, now at the University of Montreal and Center for Research in Astrophysics of Quebec), the suspected planetary system required further observations over time to confirm that the planet and star were indeed moving through space together.