Ice Water Found on Mercury!
NASA announced today that its Messenger spacecraft has discovered “compelling” evidence of frozen water and possible organic materials on Mercury’s north pole (shown left in red), confirming the decades of suspicion in the scientific community.
“The neutron data indicate that Mercury’s radar-bright polar deposits contain, on average, a hydrogen-rich layer more than tens of centimeters thick beneath a surficial layer 10 to 20 centimeters thick that is less rich in hydrogen,” according to David Lawrence, a Johns Hopkins University physics scientist working on the Messenger project.
Has NASA’s Curiosity rover made a big discovery?
NASA scientists are to checking and double-checking the results before announcing the Mars Science Laboratory’s potential findings.
Rivers on Titan |
New findings suggest the surface of Saturn’s largest moon may have undergone a recent transformation. For many years, Titan’s thick, methane- and nitrogen-rich atmosphere kept astronomers from seeing what lies beneath. Saturn’s largest moon appeared through telescopes as a hazy orange orb, in contrast to other heavily cratered moons in the solar system.
In 2004, the Cassini-Huygens spacecraft — a probe that flies by Titan as it orbits Saturn — penetrated Titan’s haze, providing scientists with their first detailed images of the surface. Radar images revealed an icy terrain carved out over millions of years by rivers of liquid methane, similar to how rivers of water have etched into Earth’s rocky continents.
While images of Titan have revealed its present landscape, very little is known about its geologic past. Now researchers at MIT and the University of Tennessee at Knoxville have analyzed images of Titan’s river networks and determined that in some regions, rivers have created surprisingly little erosion. The researchers say there are two possible explanations: either erosion on Titan is extremely slow, or some other recent phenomena may have wiped out older riverbeds and landforms.
“It’s a surface that should have eroded much more than what we’re seeing, if the river networks have been active for a long time,” says Taylor Perron, the Cecil and Ida Green Assistant Professor of Geology at MIT. “It raises some very interesting questions about what has been happening on Titan in the last billion years.”
A paper detailing the group’s findings will appear in the Journal of Geophysical Research-Planets. continue reading
The Sun and Inner Planets Moving Through Space
An X-Class solar flare produced by sunspot group AR 1520 on July 12th, 2012.
The Hubble Space Telescope has captured images of three odd galaxies that may help scientists solve a 13 billion-year cosmic mystery.
The galaxies are so old and faint that astronomers nicknamed them “ghost galaxies” in a description. The objects are among the smallest and faintest galaxies near our own Milky Way galaxy, researchers said.
“These galaxies are fossils of the early universe: they have barely changed for 13 billion years,” scientists explained in a July 10 announcement. “The discovery could help explain the so-called ‘missing satellite’ problem, where only a handful of satellite galaxies have been found around the Milky Way, against the thousands that are predicted by theories.”
The three galaxies observed by the Hubble telescope are known as Hercules, Leo IV and Ursa Major. All three objects are small dwarf galaxies that appear to have begun forming about 13 billion years ago and then — for an unknown reason — their growth hit a cosmic wall.
Since the universe is estimated to be about 13.7 billion years old, the galaxies were born sometime within the first billion years of the cosmos.
What does space smell like?
It’s strange to think that the near-vacuum of space could have a smell, and stranger still that humans—atmospheric creatures—can actually experience it. Astronauts have consistently reported the same strange odour after lengthy space walks, bringing it back in on their suits, helmets, gloves and tools. It’s bitter, smoky, metallic smell—like seared steak, hot metal and arc welding smoke all rolled into one. NASA have asked a chemist, Steve Pearce, to reproduce the smell to use during acclimatization training, mapping out the likely chemistry using natural materials to mimic the odor for accuracy. It’s believed that the smell is caused by high-energy vibrations in particles that mix with the air when brought inside. In the future, we might even recreate the smell of the moon, Mars, Mercury or any place in the universe, provided we have the right chemical information. In fact, we can even recreate the smell of the heart of the galaxy—astronomers searching for animo acids in Sagittarius B2, a vast dust cloud in the middle of the Milky Way, have reported that due to a substance called ethyl formate, it smells and tastes of raspberries and rum—much more pleasant than seared steak and metal.
Small, rocky planets can coalesce around a wide variety of stars, suggesting that Earth-like alien worlds may have formed early and often throughout our Milky Way galaxy’s history, a new study reveals.
Astronomers had previously noticed that huge, Jupiter-like exoplanets tend to be found around stars with high concentrations of so-called “metals” — elements heavier than hydrogen and helium. But smaller, terrestrial alien planets show no such loyalty to metal-rich stars, the new study found.
“Small planets could be widespread in our galaxy, because they do not require a high content of heavy elements to form,” said study lead author Lars Buchhave, of the University of Copenhagen in Denmark.
A Diversity of Stars
Buchhave and his colleagues analyzed data from NASA’s planet-hunting Kepler space telescope, which has been continuously observing more than 150,000 stars since its launch in March 2009.
Kepler watches those stars for tiny brightness dips, some of which are caused by alien planets that cross the stars’ faces from the telescope’s perspective. To date, Kepler has flagged more than 2,300 exoplanet candidates. While just a small fraction have been confirmed, Kepler scientists estimate that at least 80 percent will end up being the real deal.
In the new study, the researchers looked at Kepler observations of 226 planet candidates circling 152 different stars. More than three-quarters of these potential planets are smaller than Neptune — i.e., their diameters are less than four times that of Earth — and some of them are as diminutive as our own planet, researchers said.
The astronomers studied the stars’ spectra and found that small, rocky worlds circle stars with a much broader range of metal content than do giant planets.
Last week, in the corners of the Internet devoted to outer space, things started to get a little, well, hot. Voyager 1, the man-made object farthest away from Earth, was encountering a sharp uptick in the number of a certain kind of energetic particles around it. Had the spacecraft become the first human creation to “officially” leave the solar system?
It’s hard to overstate how wild an accomplishment this would be: A machine, built here on Earth by the brain- and handiwork of humans, has sailed from Florida, out of Earth’s orbit, beyond Mars, beyond the gas giants of Jupiter and Saturn, and may now have left the heliosphere — tiny dot in the universe beholden to our sun. Had it really happened? How would we know?
We’re not quite there yet, Voyager’s project scientist and former head of NASA’s Jet Propulsion Lab, Edward Stone, told me. The spacecraft is on its way out — “it’s leaving the solar system” — but we don’t know how far it has to go or what that transition to interstellar space will look like.
Read more. [Image: NASA]