Tag: science

New Rosetta comet images

6:34 pm

New images from Rosetta have a resolution of 100 meters per pixel and are finding that the neck connecting the comet’s two sections is apparently much brighter than the rest of the nucleus.

As earlier images had already shown, 67P may consist of two parts: a smaller head connected to a larger body. The connecting region, the neck, is proving to be especially intriguing. “The only thing we know for sure at this point is that this neck region appears brighter compared to the head and body of the nucleus”, says OSIRIS Principal Investigator Holger Sierks from the Max-Planck-Institute for Solar System Research (MPS) in Germany. This collar-like appearance could be caused by differences in material or grain size or could be a topographical effect.

It looks like this comet is going to turn out to be one of the most fascinating objects any space probe has visited in a long time.

Leave a comment

An exoplanet with an orbit like Mars

8:31 pm

Using Kepler astronomers have discovered a Uranus-sized exoplanet with the longest known orbit, 704 days.

Kepler-421b orbits an orange, type K star that is cooler and dimmer than our Sun. It circles the star at a distance of about 110 million miles. As a result, this Uranus-sized planet is chilled to a temperature of -135° Fahrenheit.

As the name implies, Kepler-421b was discovered using data from NASA’s Kepler spacecraft. Kepler was uniquely suited to make this discovery. The spacecraft stared at the same patch of sky for 4 years, watching for stars that dim as planets cross in front of them. No other existing or planned mission shows such long-term, dedicated focus. Despite its patience, Kepler only detected two transits of Kepler-421b due to that world’s extremely long orbital period.

The planet’s orbit places it beyond the “snow line” – the dividing line between rocky and gas planets. Outside of the snow line, water condenses into ice grains that stick together to build gas giant planets.

Posted from Bright Angel Lodge on the rim of the Grand Canyon.

One comment

Caves on the Moon!

9:16 am

Scientists have now identified more than 200 cave pits on the Moon.

The pits range in size from about 5 meters (~5 yards) across to more than 900 meters (~984 yards) in diameter, and three of them were first identified using images from the Japanese Kaguya spacecraft. Hundreds more were found using a new computer algorithm that automatically scanned thousands of high-resolution images of the lunar surface from LRO’s Narrow Angle Camera (NAC).

This work is essentially the same as that done by James Fincannon and I back in 2011 (see links here, here, here, and here) but with much greater thoroughness.

8 comments

The first blank Sun since 2011

1:03 am

No sunspots on July 17, 2014

For the first time since August 14, 2011, the Sun showed no sunspots on its surface today. It started the day, July 17, 2014, with one small sunspot, but that spot apparently decayed away by the end of the day, as indicated by the fact that the sunspot number for the day was listed as zero, the first time that has happened since the solar maximum ramp up began in 2011.

This is strong evidence that the ramp down to solar minimum is beginning.

3 comments

Voyager 1 might not have left the solar system

11:56 pm

The uncertainty of science: Two scientists dispute the finding this year that Voyager 1 has entered interstellar space.

Voyager has yet to detect what scientists long predicted would be the calling card of interstellar space: a shift in the direction of the magnetic field. Scientists had expected the probe to encounter particles under the influence of the interstellar magnetic field draped over the outer shell of the heliosphere, inducing an abrupt shift. But the direction has remained stubbornly constant, and researchers can’t explain why. “This whole region is a lot messier than anyone dreamed of,” Christian says.

It’s a bit too messy for George Gloeckler and Lennard Fisk, Voyager scientists at the University of Michigan in Ann Arbor. They wondered whether the magnetic field and particle density conditions measured by Voyager could exist within the heliosphere. In a paper accepted for publication in Geophysical Research Letters, Gloeckler and Fisk argue that the outer heliosphere could allow an influx of galactic particles from beyond the bubble that would explain the density measurements.

The researchers’ analysis includes a way to definitively test the idea: If Voyager 1 is within the heliosphere, Gloeckler and Fisk note, then it should still be at the mercy of the sun’s magnetic field. If that were the case, within a year or so, Voyager should detect a 180-degree flip in the field’s direction, a regular occurrence caused by the sun’s rotation. “If that happens,” Gloeckler says, “Len and I will have a big celebration.”

I suspect that both sides are right, and that the transition into interstellar space is simply very complex. Some data will say the spacecraft is outside the solar system, while other data will say it is inside.

One comment

The elusive effort to detect gravitational waves.

9:19 am

After spending more than half a billion dollars and eight years of looking without a single detection, the Laser Interferometer Gravitational-Wave Observatory (LIGO) has gotten a major upgrade.

If commissioning continues to go relatively smoothly, plans call for the first Advanced LIGO observing run to start in late 2015. A second run, with a decent shot of finding a gravitational wave, would occur in the winter of 2016–17. (Weiss likes to point out that a 2016 discovery would be a nice 100th-anniversary commemoration of Einstein’s paper describing gravitational waves.) By the third science run, planned for 2017–18, the machine should be getting sensitive enough to almost certainly nail a detection, says Reitze.

It is hoped that the increased sensitivity, ten times better than before. will allow LIGO to finally make the first detection of a gravitational wave.

One comment

More images from Rosetta

5:24 pm

67P

The comet that Rosetta will orbit is getting stranger and stranger, with new images suggesting that it is really two objects stuck together.

The pictures show that 67P/Churyumov-Gerasimenko appears to be not one but two objects joined together. It is what scientists call a “contact binary”. How the comet came to take this form is unknown. It is possible that 67P suffered a major fracture at some point in its past; it is also possible the two parts have totally different origins.

What is clear is that the European Space Agency (Esa) mission team now has additional and unexpected considerations as it plans how to land on the comet later this year – not least, which part of the comet should be chosen for contact?

One comment

Sixty science papers retracted

9:17 am

The uncertainty of peer review: An internal investigation has caused the retraction of sixty peer-reviewed scientific papers that were published by a single journal, the Journal of Vibration and Control (JVC).

The network of JVC papers that emerged was incestuous, with the same small group of authors reviewing each other’s work and appearing together as co-authors. By the end of the year, the investigators had a list of 130 e-mail addresses associated with 60 papers, with one scientist as co-author on all of them: Chen-Yuan Chen of NPUE, who goes by “Peter.” When SAGE sent an e-mail to all 130 e-mail addresses requesting that the authors confirm their identity, none responded. “The authors were contacted again by SAGE in May 2014 to inform them that their papers would be retracted in the July 2014 issue,” says Sherman, but again none responded. According to SAGE’s official statement, Chen resigned from NPUE in February. Neither Chen nor officials at NPUE responded to e-mails from ScienceInsider

How was it possible for a scientist to become the sole reviewer on dozens of his own papers? The answer appears to be that Chen was allowed to nominate his own reviewers, who were not vetted by JVC,

Chen apparently created fake gmail accounts for both real and non-existing scientists and then chose these scientists both as his co-authors as well as his peer-reviewers.

Leave a comment

The darkest material ever made

12:00 pm

Scientists have developed a material so dark it is difficult to discern the shape of any object it coats.

The material absorbs all but 0.035 per cent of light, a new world record, and is so dark the human eye struggles to discern its shape and dimension, giving the appearance of a black hole. Named Vantablack, or super black, it also conducts heat seven and half times more effectively than copper, and is ten times stronger than steel. It is created by Surrey NanoSystems using carbon nanotubes, which are 10,000 thinner than human hair and so miniscule that light cannot get in but can pass into the gaps in between.

The pictures at the website are especially amazing. They coated half of a sheet of aluminum foil with the material and then crinkled the foil. You can see the crinkles in the uncoated material, but the coated material just looks black.

This will be very useful for astronomical instruments, as well as many other technical applications. For example, if you coat the body of your telescope with this material it will help eliminate stray light, which means that you will increase the efficiency of your observations.

5 comments

CDC suspends shipments of dangerous pathogens

8:40 am

Due to a series of recent errors and mishaps in the shipment of dangerous pathogens such as anthrax and influenza, the Centers for Disease Control (CDC) has suspended future shipments while it conducts an investigation.

After news of the anthrax exposure broke on 19 June, the CDC began investigating why its lab workers did not follow proper procedure to inactivate Bacillus anthracis spores before shipping them to another lab on the agency’s Atlanta campus. The receiving lab was not equipped to handle the pathogen, and once the mistake was discovered, more than 70 people were pre-emptively treated for anthrax infection. The CDC now says that the lab never needed to work with B. anthracis in the first place; another bacterium would have sufficed to test the diagnostic equipment that the lab was evaluating. The good news, Frieden says, is that the CDC now does not believe that anyone was actually exposed to anthrax spores.

But the agency’s ongoing investigation has revealed more bad news: on 12–13 March, the CDC’s influenza lab contaminated a harmless flu strain with the highly dangerous H5N1 variety, and sent it to a laboratory operated by the US Department of Agriculture (USDA) in Athens, Georgia. The mistake was discovered on 23 May, but Frieden says that he was not notified until 9 July. “Why it took six weeks for that to be made apparent, I can think of no valid explanation,” he says. The USDA lab was equipped to handle highly infectious agents, and the agency is confident that there were no exposures.

One comment

Venus Express is coming up for less air

11:31 pm

After spending a month dropping down deep into Venus’s atmosphere, engineers are now raising Venus Express’s orbit.

Thus routine science operations concluded on 15 May, and the spacecraft’s altitude was allowed to drop naturally from the effect of gravity, culminating in a month ‘surfing’ between 131 km and 135 km above the surface. Additional small thruster burns were used to drop the spacecraft to lower altitudes, reaching 130.2 km earlier this week. Tomorrow, it is expected to dip to 129.1 km.

After eight years orbiting Venus, the mission is finally ending. They will use the spacecraft’s thrusters to lift it back up to almost 500 kilometers, where they will then allow its orbit to naturally decay, eventually ending the mission when it burns up in the atmosphere. There is also the chance they will run out of fuel during these last burns, ending the mission slightly sooner.

Leave a comment

Dry ice evaporation creates the fresh gullies on Mars

2:59 pm

New data from Mars Reconnaissance Orbiter shows that the fresh gullies that have been seen on the Red Planet are caused by dry ice evaporation, not liquid water as had been hoped.

Dundas and collaborators used the High Resolution Imaging Science Experiment (HiRISE) camera on MRO to examine gullies at 356 sites on Mars, beginning in 2006. Thirty-eight of the sites showed active gully formation, such as new channel segments and increased deposits at the downhill end of some gullies.

Using dated before-and-after images, researchers determined the timing of this activity coincided with seasonal carbon-dioxide frost and temperatures that would not have allowed for liquid water.

Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but is plentiful on Mars. It has been linked to active processes on Mars such as carbon dioxide gas geysers and lines on sand dunes plowed by blocks of dry ice. One mechanism by which carbon-dioxide frost might drive gully flows is by gas that is sublimating from the frost providing lubrication for dry material to flow. Another may be slides due to the accumulating weight of seasonal frost buildup on steep slopes.

The findings in this latest report suggest all of the fresh-appearing gullies seen on Mars can be attributed to processes currently underway, whereas earlier hypotheses suggested they formed thousands to millions of years ago when climate conditions were possibly conducive to liquid water on Mars.

Leave a comment

The sun continues its ramp down

10:44 am

On Monday NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in June. As I do every month, I am posting it here, below the fold, with annotations to give it context.

The decline in sunspots continued for the fourth month in a row, increasing the likelihood that the peak of solar maximum has finally come and gone and that we now seeing the beginning of the ramp down to solar minimum. This resulting solar maximum comes close to matching the science community’s final prediction (indicated by the red line), though that prediction was not detailed enough to include the distinct and unusual double peak for this maximum.
» Read more

5 comments

The effort to resurrect ISEE-3’s is over

9:42 am

The private effort to resurrect the 1980s research probe ISEE-3 has been stymied by a non-working propulsion system.

Before the July 9 attempt, the ISEE-3 Reboot Project thought it had a chance of completing its planned trajectory correction maneuver. The spacecraft’s small hydrazine thrusters were spun up July 3, and systems appeared nominal, Cowing said. On July 8, the spacecraft even managed to perform one of the six multipulse burns that would have set it up for a return to the orbit into which it was launched in 1978.

But further attempts to activate the thrusters July 8 proved unsuccessful, as were all attempts the following day. After eliminating a malfunctioning valve as the cause of the problem, the ISEE-3 Reboot Project was forced to conclude that the satellite’s hydrazine fuel simply was not being pushed through its plumbing at the right pressure to conduct a burn.

The spacecraft is in science mode and will gather data as long as it is in communication range, which will only be for another three months.

Leave a comment

Fast radio pulses exist, come from outside the galaxy, and no one knows what they are

9:32 am

A new astronomical mystery: The Arecibo radio telescope has confirmed the existence of fast radio pulses.

Fast radio bursts (FRBs) are bright flashes of radio waves that last only a few thousandths of a second. Scientists using the Parkes Observatory in Australia have recorded such events for the first time, but the lack of any similar findings by other facilities led to speculation that the Australian instrument might have been picking up signals originating from sources on or near Earth. The discovery at Arecibo is the first detection of a fast radio burst using an instrument other than the Parkes radio telescope. The position of the radio burst is in the direction of the constellation Auriga in the Northern sky. …

“Our result is important because it eliminates any doubt that these radio bursts are truly of cosmic origin,” continues Victoria Kaspi, an astrophysics professor at McGill University in Montreal and Principal Investigator for the pulsar-survey project that detected this fast radio burst. “The radio waves show every sign of having come from far outside our galaxy – a really exciting prospect.”

Exactly what may be causing such radio bursts represents a major new enigma for astrophysicists. Possibilities include a range of exotic astrophysical objects, such as evaporating black holes, mergers of neutron stars, or flares from magnetars — a type of neutron star with extremely powerful magnetic fields.

Be warned: All of the above theories could also be wrong. These fast radio flashes could just as easily turn out to be something entirely unpredicted.

Leave a comment

Rosetta snaps more comet pictures

9:23 am

rotating comet nucleus

Rosetta’s new images of Comet 67P/Churyumov-Gerasimenko show the very irregular shape and rotation of its nucleus.

These images were taken on July 4 from a distance of only 23,000 miles. The rendezvous is expected in early August, with the touchdown of Rosetta’s landing probe Philae sometime in November after they have done a reconnaissance of the nucleus to pick a landing spot.

Leave a comment

ISEE-3 effort aborted?

4:07 pm

The engineers trying to resurrect ISEE-3 think their engine burn yesterday ended prematurely because the spacecraft’s supply of nitrogen needed for such a burn has been depleted.

They have still not given up hope, but it sounds like it is increasingly unlikely that they will be able to shift the spacecraft’s orbit as needed.

3 comments

Mapping the inside of Mt St. Helens

9:37 am

A new array of seismometers, combined with a series of planned explosions, will be used to map the interior of the Mt. St. Helens volcano to a depth of eighty kilometers or fifty miles.

To get the job done, starting next week roughly 65 people will fan out across the mountain to deploy 3,500 small seismometers along roads and back-country trails. They will drill 24 holes some 25 metres deep, drop in industrial explosives used for quarrying, and refill the holes (see ‘Under the dome’). The plan is to detonate the explosives in separate shots over four nights. Each blast will shake the ground as much as a magnitude-2 earthquake.

Results from the active blasts will be combined with the passive seismic part of the experiment, which is already under way: 70 larger seis­mometers around the mountain are measuring how long waves from natural earthquakes take to travel through the ground. Their data can be used to probe as far as 80 kilo­metres down, says Vidale.

3 comments

ISEE-3 engine burn

9:33 pm

The major course correction burn for ISEE-3 was only partially successful today.

We managed to conduct the first segment (composed of 63 thruster pulses) but encountered problems with the second and halted the remainder of segment firings. Today’s burn was supposed to be 7.32987 m/s. We’re looking at data and formulating a plan for tomorrow. Our window tomorrow (Wednesday) at Arecibo opens at 12:39 pm EDT and extends to 3:26 pm EDT.

6 comments

A source for the most powerful cosmic rays?

8:58 am

Astronomers think they have discovered a region in the sky, within or near the Milky Way, which might be the source of the most energetic cosmic rays

Nobody knows how ultra–high-energy cosmic rays—mainly protons or heavier atomic nuclei—acquire energies millions of times higher than have been achieved with humanmade particle accelerators. (Physicists dubbed one of the first ones observed the “Oh-My-God particle.”) Lower energy cosmic rays are thought to spring from the lingering remnants of stellar explosions called supernovas. But such clouds are far too small to produce the highest energy cosmic rays. Instead, theorists generally expect that the most energetic cosmic rays rev up over millions of years in unidentified accelerators the size of galaxies.

The Telescope Array aims to help solve that mystery. When a high-energy cosmic array strikes the atmosphere, it disappears in an avalanche of lower energy particles. Those particles trigger the detectors in the array, enabling researchers to deduce the direction and energy of the original cosmic ray. From 2008 to 2013, researchers spotted 72 cosmic rays with energies above 57 exaelectron volts—15 million times the highest energy achieved with a particle accelerator. And 19 of them appear to cluster in a hotspot in the sky about 20° in radius, as Hiroyuki Sagawa, a co-representative for the Telescope Array team from the University of Tokyo, reported today in a press conference at the university. [emphasis mine]

The low number of detections, 19 out of 72 total, that seem to come from this wide 20 degree region, suggests that this report falls most certainly under the heading of “the uncertainty of science.” I would not be surprised at all if this conclusion does not stand up after further research.

Nonetheless, the article is worth reading because it outlines nicely this astronomical mystery. Something out there accelerates these particles to these high energies, and astronomers do not yet know what that something is.

Leave a comment

ISEE-3 engine burn tomorrow

3:46 pm

The private effort to resurrect the 1970’s sun-observing space probe ISEE-3’s will attempt its first full engine burn on July 8.

They hope to get the spacecraft back into one of the Earth-Sun Lagrangian points where it can be controlled reliably from Earth and can thus resume its study the solar wind, as originally designed. They have most of July to make the burn that will shift the orbit appropriately, so if this first attempt fails they can still make it happen.

3 comments

Problems with the European Gaia space telescope

7:43 pm

Shades of Hubble: The first data from Europe’s Gaia space telescope, launched to map a billion Milky Way stars, will be delayed 9 months while engineers grapple with several problems.

Gaia managers started taking test images early this year, but soon noticed three issues. For one, more light than anticipated is bending around the 10-metre sunshield and entering the telescope.

Small amounts of water trapped in the spacecraft before launch are being released now that the telescope is in the vacuum of space, and more ice than calculated is accumulating on the telescope’s mirrors. In addition, the telescope itself is expanding and contracting by a few dozen nanometres more than expected because of thermal variations.

Mission managers say the number of stars detected will remain the same even if these complications remain untreated, but the accuracy in measurements of the fainter stars will suffer.

Unlike Hubble, however, there is no way to send a shuttle and a team of astronauts to Gaia to fix it. And it sounds like these issues will have an impact on the telescope’s abilities to gather its intended data.

This story raises my hackles for another reason. Gaia was a very technically challenging space telescope to build, but it was far easier and less cutting edge than the James Webb Space Telescope. It also cost far less. What will happen when Webb gets launched later this decade? How likely is it to have similar issues? Based on a story I just completed for Sky & Telescope on the difficulties of building ground-based telescopes, I’d say Webb is very likely to have similar problems, with no way to fix them. The American astronomy community could then be faced with the loss of two decades of research because they had put all the eggs into Webb’s basket, and thus had no money to build anything else.

15 comments

Plastic bags do not kill birds and fill the oceans

9:49 am

Another environmental claim turns out to be vastly exaggerated: The scientist who claimed that islands of plastic bags were filling the oceans has found that his claim was bogus.

The scientist whose findings environmentalists used to shame us into bringing our own reusable bags to the grocery store now says that his estimate of one million tons of plastic floating in the ocean may have been off by a factor of perhaps 143. His latest estimate ranges from 7,000 to 35,000 tons, and even most of that has biodegraded into granules. …

Also doubtful: The environmentalist claim that 1.5 million marine animals choke to death each year on plastic bags that ran away from home for a life at sea. They’ve revised their estimates downward to 6.6 percent of that, but even the new figure has no empirical support.

But remember, Barack Obama says the science is settled, and that anyone who questions him or expresses any doubt is the equivalent of a Holocaust denier.

2 comments

Two exoplanets disappear

4:53 pm

The uncertainty of science: Two exoplanets orbiting Gliese 581, both thought to be in the habitable zone, have now been proven to not even exist.

“We’ve proven that some of the controversial signals from Gliese 581 don’t come from two proposed Goldilocks planets, but instead are coming from activity within the star itself masquerading as planets,” lead study author Paul Robertson, an astronomer at Pennsylvania State University in University Park, told Space.com.

This result should serve as a strong reminder: Though it is likely that many if not most of the so far discovered exoplanets are real, it is also likely that many will turn out to be false positives. We won’t have solid real knowledge about them until we can actually get a close look at them, which will require far better telescopes in space, and maybe even interstellar missions to them.

Leave a comment

Telescope teamwork produces spectacular galaxy image

11:55 am

M106

Combining images from a host of space and ground-based telescopes, astronomers have created a spectacular image of the galaxy M106.

This galactic fireworks display is taking place in NGC 4258 (also known as M106), a spiral galaxy like the Milky Way. This galaxy is famous, however, for something that our Galaxy doesn’t have – two extra spiral arms that glow in X-ray, optical, and radio light. These features, or anomalous arms, are not aligned with the plane of the galaxy, but instead intersect with it.

The anomalous arms are seen in this new composite image of NGC 4258, where X-rays from NASA’s Chandra X-ray Observatory are blue, radio data from the NSF’s Karl Jansky Very Large Array are purple, optical data from NASA’s Hubble Space Telescope are yellow and blue, and infrared data from NASA’s Spitzer Space Telescope are red.

A new study of these anomalous arms made with Spitzer shows that shock waves, similar to sonic booms from supersonic planes, are heating large amounts of gas – equivalent to about 10 million Suns. What is generating these shock waves? Radio data shows that the supermassive black hole at the center of NGC 4258 is producing powerful jets of high-energy particles. Researchers thinkthat these jets strike the disk of the galaxy and generate shock waves. These shock waves, in turn, heat some of the gas – composed mainly of hydrogen molecules – to thousands of degrees.

The astronomers also used the Herschel Space Observatory to confirm the data from Spitzer.

Leave a comment
1 … 185 186 187 188 189 … 275