Tuesday, September 28, 2010
"Although this particular object won't hit Earth in the immediate future, its discovery shows that Pan-STARRS is now the most sensitive system dedicated to discovering potentially dangerous asteroids," said Robert Jedicke, a University of Hawaii member of the PS1 Scientific Consortium, who is working on the asteroid data from the telescope. Most of the largest PHOs have already been catalogued, but scientists suspect that there are many more under a mile across that have not yet been discovered.
Friday, September 24, 2010
Stars are formed as the dense core regions of cosmic clouds of gas and dust ("molecular clouds") collapse under their own gravity. What happens during the earliest phases of this collapse is largely unknown. Enter an international team of astronomers who have discovered a new phenomenon which promises information about the crucial earliest phase of the formation of stars and planets: "coreshine," the scattering of mid-infrared light (which is ubiquitous in our galaxy) by dust grains inside such dense clouds.
Thursday, September 23, 2010
This configuration offers multi-directional views of the electrons and ions that make up the escaping solar wind. On occasion, the planet Mercury appears in the field of view of one or both satellites. In addition to its appearance as a bright disk of reflected sunlight, a "tail" of emission can be seen in some of the images
Wednesday, September 22, 2010
From such blurred images obtained by NASA's Fermi Gamma-Ray Space Telescope, the researchers found that the average magnetic field had a "femto-Gauss" strength, just one-quadrillionth of the Earth's magnetic field. The universal magnetic fields may have formed in the early universe shortly after the Big Bang, long before stars and galaxies formed.
The latest evidence supports other scenarios. Material blasted off Mars's surface by a colliding space rock could have clumped together to form the Phobos moon. Alternatively, Phobos could have been formed from the remnants of an earlier moon destroyed by Mars's gravitational forces. However, this moon might itself have originated from material thrown into orbit from the Martian surface.
Monday, September 20, 2010
Earth-Jupiter encounters happen every 13 months when the Earth laps Jupiter in their race around the sun. But because Earth and Jupiter do not orbit the sun in perfect circles, they are not always the same distance apart when Earth passes by. On Sept. 20th, Jupiter will be as much as 75 million km closer than previous encounters and will not be this close again until 2022.
Friday, September 17, 2010
That means astronomers using Earthly telescopes can only guess at how many bodies are out there, what they look like, and what they're made of. Now, using archived pictures from the Hubble Space Telescope, a team of scientists has found a way to spot TNOs, and they've added 14 more to the catalog. The trick to finding them is to look for the equivalent of meteor streaks in Hubble shots of other objects.
"If we can get people to notice the moon a little more, they might notice it when it's in the news," said Andy Shaner, a spokesperson for the Lunar and Planetary Institute in Houston, which is helping to coordinate the event. Around 370 official events are currently scheduled in nearly 50 countries. But people can have their own moon party from just about anywhere, Shaner said.
The new data reveal previously unseen compositional differences in the moon's crustal highlands and have confirmed the presence of material surprisingly abundant in silica -- a compound containing the chemical elements silicon and oxygen -- in five distinct lunar regions. For the first time ever, Diviner is providing scientists with global, high-resolution infrared maps of the moon, which are enabling them to make a definitive identification of silicates commonly found within its crust.
Thursday, September 16, 2010
This year comet Hartley 2 is on course to make its closest pass by Earth at a mere 11 million miles on October 20—and a dark, moonless sky in mid-October will help create ideal viewing conditions, astronomers say. "Before mid-October, Northern Hemisphere observers will be able to see the comet nearly all night long in the northeast," said Anthony Cook, an astronomer at the Griffith Observatory in California. "After mid-October it can be seen as early as 11:30 p.m. [local time] but is best just before dawn."
Tuesday, September 14, 2010
The star in question, known as BP Piscium (BP Psc), appears to be a more evolved version of our Sun, but with a dusty and gaseous disk surrounding it. A pair of jets several light years long blasting out of the system in opposite directions has also been seen in optical data. Astronomers have suggested that BP Psc is an old star in its so-called red giant phase. And, rather than being hallmarks of its youth, the disk and jets are, in fact, remnants of a recent and catastrophic interaction whereby a nearby star or giant planet was consumed by BP Psc.
Monday, September 13, 2010
The trouble is that the gloves, like the entire space suit, need to simulate the pressure of Earth's atmosphere in the chilly, airless environment of space. The rigid, balloonlike nature of gas-pressurized gloves makes fine motor control a challenge during extravehicular activities (EVAs), aka spacewalks. In several cases, sustained pressure on the fingertips during EVAs caused intense pain and led to the astronauts' nails detaching from their nailbeds, a condition called fingernail delamination.
Friday, September 10, 2010
Unlike the stars and gases of the Milky Way, which stretch away from Earth for light-years, the source of the zodiacal light lies between the inner planets of our solar system. The dusty disk, also called the zodiacal cloud, radiates from near the sun out beyond the orbit of Mars, toward Jupiter. The dust reflects and scatters sunlight in such a way that it creates a visible glow for observers on Earth.
Thursday, September 9, 2010
This is forcing scientists to rethink their theories on the maximum brightness of ultra-luminous X-ray sources, and provides support to the idea that HLX-1 may contain an intermediate mass black hole. While astrophysicists have suspected that an intermediate class of black hole might exist, with masses between a hundred and several hundred thousand times that of the Sun, such black holes had not previously been reliably detected and their existence has been fiercely debated among the astronomical community.
Wednesday, September 8, 2010
Asteroid 2010 RX30, thought to be 32 to 65 feet long, will pass within 154,000 miles of Earth shortly before 3 a.m. PDT Wednesday. The second one, dubbed 2010 RF12, will fly by about 11 hours later at a distance of about 49,000 miles. NASA says the second one is 20 to 46 feet long.
Tuesday, September 7, 2010
Like the chocolates and fruity candies inside a piñata, these asteroids come in assorted colors and compositions. Some are dark and dull; others are shiny and bright. The Spitzer observations of 100 known near-Earth asteroids demonstrate that their diversity is greater than previously thought.
Thursday, September 2, 2010
In principle, it is possible to propel an orbiting spacecraft without fuel by using a long piece of metal to interact with the magnetic field surrounding our planet. "You're essentially pushing against the Earth's magnetic field," says Les Johnson of NASA's Marshall Space Flight Center in Huntsville, Alabama. While in space, the spacecraft unfurled the 300-metre-long "tether" – a 2.5-centimetre-wide metallic ribbon.