Tag: science

Possible ebola exposure at CDC

2:54 pm

Government marches on! As many as a dozen scientists might have been mistakenly exposed to ebola at an Atlanta CDC lab.

The potential exposure took place Monday when scientists conducting research on the virus at a high-security lab mistakenly put a sample containing the potentially infectious virus in a place where it was transferred for processing to another CDC lab, also in Atlanta on the CDC campus.

The CDC statement is remarkably uninformative. From what little they say, it appears as if the sample was left out uncovered in the lab as people came in and out. It also suggests that this unsecured sample was also transferred improperly to another lab.

No need to worry however. Just like its previous investigation of errors in the handling of anthrax, CDC officials are on the case, doing investigations and writing press releases, just so us ordinary citizens won’t get worried and cut their funds.

0 comments

Loose fibers significantly cuts Gaia’s output

5:24 pm

Europe’s Gaia telescope, designed to precisely measure the motions of a billion stars in the Milky Way, will have its accuracy cut in half because of the presence of loose fibers on the telescope’s sun shield that are allowing too much stray light in.

These fibres were spotted on Gaia before launch, but cutting them off was considered too risky, because that could allow small particles to enter the spacecraft. Another option, taping them down, was also ruled out because the increased stiffness could prevent the sunshield from unfolding.

The stray light shouldn’t affect measurements of the galaxy’s brightest stars, says Gaia science team member Anthony Brown at the Leiden Observatory in the Netherlands, but it will double the expected errors on most of the stars in the Milky Way, which are much fainter.

For astronomers this is a great tragedy. Gaia will still teach us much, just not as much as they had hoped.

2 comments

New data says volcanoes, not asteroids, killed dinosaurs

1:38 pm

The uncertainty of science: A careful updating of the geological timeline has strengthened the link between the dinosaur extinction 66 million years ago and a major volcanic event at that time.

A primeval volcanic range in western India known as the Deccan Traps, which were once three times larger than France, began its main phase of eruptions roughly 250,000 years before the Cretaceous-Paleogene, or K-Pg, extinction event, the researchers report in the journal Science. For the next 750,000 years, the volcanoes unleashed more than 1.1 million cubic kilometers (264,000 cubic miles) of lava. The main phase of eruptions comprised about 80-90 percent of the total volume of the Deccan Traps’ lava flow and followed a substantially weaker first phase that began about 1 million years earlier.

The results support the idea that the Deccan Traps played a role in the K-Pg extinction, and challenge the dominant theory that a meteorite impact near present-day Chicxulub, Mexico, was the sole cause of the extinction. The researchers suggest that the Deccan Traps eruptions and the Chicxulub impact need to be considered together when studying and modeling the K-Pg extinction event.

The general public might not know it, but the only ones in the field of dinosaur research that have said the asteroid was the sole cause of the extinction have been planetary scientists.

5 comments

CO2 satellite overcomes design flaw

10:37 am

Despite a decade of development, including the production of two satellites, the Orbiting Carbon Observatory-2 was launched in July with a basic design flaw that was never spotted.

Scientists and engineers on the project have ridden an emotional roller coaster. In 2009, a rocket failure doomed the Orbiting Carbon Observatory, their first attempt at a carbon-mapping probe. Its replacement, OCO-2, launched successfully. But after the JPL turned on the main instrument — a trio of spectrometers that measure sunlight light reflecting off Earth’s surface — the team discovered a problem in OCO-2’s data. They eventually determined that it was caused by a design flaw that reduced the amount of light entering the instrument during one mode of operation. The problem dated to 2004 and had never been caught in testing, says JPL’s David Crisp, the science team leader of the OCO-2 mission. “It was a stupid mistake. Embarrassing to the instrument designer and to me,” he says.

This flaw was apparently in both OCO satellites and was never noticed.

Fortunately, they have improvised a work-around that is allowing the spacecraft to get its data, which interestingly shows the highest concentrations of CO2 are coming not from the U.S. and the First World but from poorer parts of Africa and South America (caused by “burning savannas and forests,” not SUVs) and from China.

1 comment

The seas of Titan

9:27 am

Thar’s black gold up thar! Data from Cassini has confirmed the presence of ocean waves on Titan’s seas, while also providing suggesting that they are made mostly of liquid methane, not ethane as had been predicted.

The maximum depth of Kraken Mare appears to be 160 meters, and Ligeia Mare could be as much as 200 meters deep, reported Marco Mastrogiuseppe of Sapienza University of Rome. The fact that the radar signals could bounce off the sea bottom suggests that the seas were more transparent than expected and thus must contain mostly methane, not ethane. Hayes says his best estimate is about 90% methane. Essam Marouf, a planetary scientist at San José State University in California, reported on the first results from a separate radar experiment that sent radar reflections to Earth instead of back to the spacecraft. Those tests provide independent evidence that the seas are dominated by methane, Marouf says, and it implies that the lakes are kept filled by precipitating methane.

As the article also notes, this methane is “55 times Earth’s oil reserves.”

1 comment

Venus Express mission ends

6:51 pm

After eight years, the European Space Agency has officially ended the Venus Express mission.

After this month of ‘surfing’ in and out of the atmosphere at low altitudes, the lowest point of the orbit was raised again through a series of 15 small thruster burns, such that by 26 July it was back up to about 460 km, yielding an orbital period of just over 22 hours. The mission then continued in a reduced science phase, as the closest approach of the spacecraft to Venus steadily decreased again naturally under gravity.

Under the assumption that there was some propellant still remaining, a decision was taken to correct this natural decay with a new series of raising manoeuvres during 23–30 November, in an attempt to prolong the mission into 2015. However, full contact with Venus Express was lost on 28 November. Since then the telemetry and telecommand links had been partially re-established, but they were very unstable and only limited information could be retrieved.

The agency has decided that further attempts to contact the spacecraft would essentially be a wasted effort, and has closed the books on this very successful mission. The spacecraft itself will soon burn up in Venus’s atmosphere when its orbit decays.

0 comments

Curiosity finds organic materials on Mars, including fluctuating levels of methane

2:53 pm

Data from Curiosity has found both organic chemicals in the surface of Mars as well as quickly changing levels of methane in the nearby atmosphere.

NASA’s Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill. “This temporary increase in methane — sharply up and then back down — tells us there must be some relatively localized source,” said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”

The organic material does not prove there is or was ever life on Mars. What it shows is that conditions on Mars could have once supported life. The methane detection, however, is a more significant finding, as it suggests that something very nearby to Curiosity is causing the spike. It could be life, or it could be chemical activity, but in either case, it means there is activity.

The one caveat is that the spike still did not amount to much, 7 parts per billion. Whatever is causing it is not really doing very much.

6 comments

Evaporating dry ice chunks create gouges on Mars

9:27 am

Scientists think they have solved the mystery of the gouges that appear seasonally on some hillsides on Mars: Chunks of dry ice that slide down the slope and then evaporate, leaving no trace.

During the martian winter, carbon dioxide ice freezes over parts of the planet’s surface and sublimates back into a gas during the spring thaw. But according to the model presented here today at a meeting of the American Geophysical Union, chunks of warming dry ice may also break off from the crests of dunes and skid down slopes. This is no ordinary tumble—according to the model, the bases of the chunks are continually sublimating, resulting in a hovercraftlike motion that gouges the dune while propelling the ice down slopes. Solid ice that survives to the bottom settles into a pit before dissipating back into the atmosphere.

1 comment
1 … 486 487 488 489 490 … 729