India’s Mangalyaan Mars orbiter is now halfway to Mars.
India’s Mangalyaan Mars orbiter is now halfway to Mars.
India, unlike Israel, wants to conquer the stars, so the success of their first interplanetary mission means a lot to them.
Tag: science
Scientists have found that Saturn’s hexagon-shaped jet stream is deeply rooted and that its rotation might be revealing the planet’s rotation as well.
Scientists have found that Saturn’s hexagon-shaped jet stream is deeply rooted and that its rotation might be revealing the planet’s rotation as well.
Due to the tilt of approximately 27º of the planet Saturn, its polar atmosphere undergoes intense seasonable variations with long polar nights lasting over seven years, followed by a long period of 23 years of variable illumination. However, the seasonal variations do not affect the hexagon and its jet stream at all, so both are part of an extensive wave, deeply rooted in Saturn’s atmosphere. The UPV/EHU researchers suggest that the hexagon and its stream are the manifestation of a “Rossby wave” similar to those that form in the mid-latitudes of the earth. On our planet the jet stream meanders from west to east and brings, associated with it, the system of areas of low pressure and anticyclones which we have been seeing regularly on weather maps.
On Saturn, a hydrogen gas planet, ten times the size of the Earth, cold in its upper clouds, without a solid surface, and with an atmosphere as deep as that of an ocean, “the hexagonal wavy motion of the jet stream is expected to be propagated vertically and reveal to us aspects of the planet’s hidden atmosphere,” pointed out Agustín Sánchez-Lavega, Head of the Planetary Sciences research group. “The movement of the hexagon could therefore be linked to the depths of Saturn, and the rotation period of this structure, which, as we have been able to ascertain, is 10 hours, 39 minutes and 23 seconds, could be that of the planet itself,” he added. Saturn is the only planet in the Solar System whose rotation period is not yet known.
Geologists, using computer models, have reconstructed the size and impact velocity of a giant asteroid that hit the Earth approximately 3.26 billion years ago.
Geologists, using computer models, have reconstructed the size and impact velocity of a giant asteroid that hit the Earth approximately 3.26 billion years ago.
This is a fascinating result, but it is very important to recognize its very large uncertainties. The article for example says almost nothing about how these conclusions were reached, except for this one paragraph:
Lowe, who discovered telltale rock formations in the Barberton greenstone a decade ago, thought their structure smacked of an asteroid impact. The new research models for the first time how big the asteroid was and the effect it had on the planet, including the possible initiation of a more modern plate tectonic system that is seen in the region, according to Lowe. [emphasis mine]
I have highlighted that one word because it reveals a great deal. What they did was to create a computer model of the data they had, which was merely very unusual geology spread over a certain region called the Barberton Greenstone Belt. Note also that this region is not where the impact occurred. “The study’s co-authors think the asteroid hit the Earth thousands of kilometers away from the Barberton Greenstone Belt, although they can’t pinpoint the exact location.”
Curiosity catches a mysterious flash of light on the Martian horizon.
Curiosity catches a mysterious flash of light on the Martian horizon.
Be assured, despite what some reports are suggesting, it isn’t an alien flashing a mirror at us. The top theory now is that Curiosity caught a reflection off a “glinty” rock.
The Sun continues to hiccup
It’s sunspot time again! On Monday NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in February. I am once again posting it here, below the fold, with annotations.
Like it did in January, the Sun’s second peak of the solar maximum continued to beat its first peak, an unprecedented event. Though activity dropped slightly, it still remained above prediction and was only slightly below the first peak’s maximum. Overall, the second peak has been much stronger than the first, something that scientists have never seen before. In the past, when the Sun had a double peaked solar maximum, the second peak was always weaker. Not this time!
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The oldest galaxy known might be a tiny dwarf galaxy orbiting the Milky Way.
The oldest galaxy known might be a tiny dwarf galaxy orbiting the Milky Way.
Segue 1 is very, very tiny. It appears to contain only a few hundred stars, compared with the few hundred billion stars in the Milky Way Galaxy. Researchers led by Anna Frebel of the Massachusetts Institute of Technology in Cambridge collected detailed information on the elemental composition of six of the brightest of Segue 1’s stars using the Las Campanas Observatory’s Magellan Telescopes in Chile and the Keck Observatory in Hawaii. The measurements, reported in a paper accepted for Astrophysical Journal and posted on the arXiv repository, revealed that these stars are made almost entirely of hydrogen and helium, and contain just trace amounts of heavier elements such as iron. No other galaxy studied holds so few heavy elements, making Segue 1 the “least chemically evolved galaxy known.”
Complex elements are forged inside the cores of stars by the nuclear fusion of more basic elements such as hydrogen and helium atoms. When stars explode in supernovae, even heavier atoms are created. elements spew into space to infuse the gas that births the next generation of stars, so that each successive generation contains more and more heavy elements, known as metals. “Segue 1 is so ridiculously metal-poor that we suspect at least a couple of the stars are direct descendants of the first stars ever to blow up in the universe,” says study co-author Evan Kirby of the University of California, Irvine.
As the NASA lunar probe LADEE nears its planned end — where it will crash onto the Moon — the scientists running it admit that they have as yet been unable to solve its primary scientific question about levitating lunar dust.
As the NASA lunar probe LADEE nears its planned end — where it will crash onto the Moon — the scientists running it admit that they have as yet been unable to solve its primary scientific question about levitating lunar dust.
A major goal of the mission was to understand a bizarre glow on the Moon’s horizon, spotted by Apollo astronauts just before sunrise. “So far we haven’t come up with an explanation for that,” project scientist Rick Elphic, of NASA’s Ames Research Center in Moffett Field, California, said at a media briefing on 3 April. One leading idea is that the Sun’s ultraviolet rays cause lunar dust particles to become electrically charged. That dust then lofts upwards, forming a cloud that caught the light and the astronauts’ eyes.
LADEE carries an instrument that measures the impact of individual dust particles, as well as the collective signal from smaller particles. Lunar scientists had expected a certain amount of tiny dust to explain what the Apollo astronauts saw. But LADEE didn’t find it. “We did measure a signal that indicates that the amount of lofted dust has to be at least two orders of magnitude below the expectations that were based on the Apollo reports,” says Mihály Horányi, the instrument’s principal investigator, who is at the University of Colorado. Perhaps the dust lofting happens only occasionally, he suggests, and the astronauts were in just the right place at the right time to see it.
This remains an important question. Knowing what caused that horizon glow and knowing how often it occurs is essential knowledge for any future lunar base or research station.
Because of a $10 million shortfall in its astrophysics budget, NASA is weighing the fate of nine operating space telescopes.
Because of a $10 million shortfall in its astrophysics budget, NASA is weighing the fate of nine operating space telescopes.
Six of the projects vying for extended funding are U.S.-based. Three are overseen by international space agencies and have U.S. partners.
The NASA missions are: the Fermi Gamma-ray Space Telescope; the Nuclear Spectroscopic Telescope Array X-ray observatory; the infrared Spitzer Space Telescope; the Swift Telescope, which tracks gamma-ray bursts; a proposed Kepler space telescope follow-on mission known as K2; and the Wide-field Infrared Survey Explorer, which was brought out of hibernation last year to help search for asteroids on a collision course with Earth.
Also in the running are two European Space Agency missions, XMM-Newton — an X-ray observatory — and Planck, which studied relic radiation from the Big Bang. Planck was decommissioned in October, but its data analysis program continues.
The final contender is Japan’s Suzaku X-ray telescope.
A skydiver’s helmet cam captures a meteorite zipping past him as it falls.
A skydiver’s helmet cam videotapes a meteorite zipping past him as it falls.
The incident happened back in the summer of 2012, when skydiver Anders Helstrup and other members of the Oslo Parachute Club took to the skies above Hedmark, Norway. Helstrup documented the jump with two cameras fixed to the front and back of his helmet. Helstrup tells NRK (the largest media outlet in Norway) that on the way down he felt “something” happen, but didn’t know what. It was only after landing and reviewing his camera footage that he discovered something shocking: a rock had fallen from the heavens and missed him by just a few yards.
Video below the fold. The news woman is annoying, but the footage is quite cool.
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In a new study scientists confirm their belief that a sea of water the size of Lake Superior exists inside the Saturn moon Enceladus.
In a new study scientists confirm their belief that a sea of liquid water the size of Lake Superior exists inside the Saturn moon Enceladus.
A scientist whistleblower has found that publicly questioning bad science papers vs privately notifying the publisher significantly increases the chances of getting them retracted.
Surprise, surprise! A scientist whistleblower has found that publicly questioning bad science papers vs privately notifying the publisher significantly increases the chances of getting them retracted.
[Paul] Brookes ran the blog Science Fraud from July 2012 to January 2013, before closing it down in response to threats of legal action. For the PeerJ study, Brookes compared the outcomes of two sets of papers — 274 whose alleged data problems he chronicled on his blog, and 223 that he was e-mailed about but did not post before he shut the site down. Those private e-mails, he says, were also copied to the relevant journals, funding agencies and authors’ research institutions, so authorities would also have had the opportunity to review the allegations.
Of the 274 papers Brookes blogged about, 16 were retracted and 47 corrected by December 2013, he reports, meaning that action was taken in 23% of the cases. But of the 223 unpublicized papers, only two were retracted and five corrected — a rate of 3%.
As always, the more freedom and openness we have, the better. The only people who suffer in such a situation are the incompetent and dishonest ones.
A new analysis of data from Messenger suggests that violent explosive volcanism occurred throughout much of Mercury’s history.
A new analysis of data from Messenger suggests that violent explosive volcanism occurred throughout much of Mercury’s history.
What is interesting about this result is that previously it was believed that explosive volcanism didn’t happen at all on Mercury.
On Earth, volcanic explosions like the one that tore the lid off Mount St. Helens happen because our planet’s interior is rich in volatiles — water, carbon dioxide and other compounds with relatively low boiling points. As lava rises from the depths toward the surface, volatiles dissolved within it change phase from liquid to gas, expanding in the process. The pressure of that expansion can cause the crust above to burst like an overinflated balloon.
Mercury, however, was long thought to be bone dry when it comes to volatiles, and without volatiles there can’t be explosive volcanism. But that view started to change in 2008, after NASA’s MESSENGER spacecraft made its first flybys of Mercury. Those glimpses of the surface revealed deposits of pyroclastic ash — the telltale signs of volcanic explosions — peppering the planet’s surface. It was a clue that at some point in its history Mercury’s interior wasn’t as bereft of volatiles as had been assumed.
The new conclusions have not only found evidence of explosive volcanism, it found a wide range of ages for these deposits, indicating that the explosive volcanism took place across an extended period of time.