Tag: science

Ebola patient arrives in U.S.

12:11 am

Doctors in charge of the specialized isolation unit for treating dangerous infectious diseases are confident that they will be able to treat the infected patients safely without the disease escaping.

I have complete confidence that a well run facility like this, with modern technology, could keep the disease isolated. The key words, however, are “well run.” I pray that this description still applies to Emory University Hospital.

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Comet 67P from 1000 k

11:06 pm

67P from 1000 kilometers

Above is a new image of Comet 67P as seen from about 1000 kilometers, or about 620 miles, released by the Rosetta science team today. The image was taken on August 1 and has been processed somewhat to bring out the details. The black spot near the junction between the nucleus’s two sections is not real but an artifact of the camera’s CCD.

This image is the first real clear and sharp look at the nucleus, and what it shows us is a surface quite different from the many other asteroids that science probes have imaged close-up in the past. From this angle there are far few craters visible then is normally seen on asteroids, and the surface has complex roughness and pitted look that I suspect the planetary geologists are right now scratching their heads about and waving their arms trying to explain. My first guess, which no one should take too seriously, is that as material vents off the comet when it gets close to the Sun it leaves behind these scars.

One more thing: If you go here you can see a number of additional image releases in the last 24 hours, all fascinating. This link explains that the features that looked like craters in earlier images were actually artifacts from the camera’s CCD.

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Don’t buy stock yet in that “impossible” space drive

7:46 pm

The uncertainty of science and engineering: A physicist takes a close and skeptical look at the “impossible” space drive that NASA engineers discovered seemed to work. Key quote:

“All in all,” Lee concluded, “it will take a lot more information before we can judge whether the thrust is really a thrust or not.”

Read the whole article. They point out the areas of doubt and weakness, as well as the possibilities.

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Getting closer

8:29 am

Comet 67P on July 31

This image of Comet 67P from Rosetta was taken yesterday. Though it has not been processed like the image I posted yesterday, more details continue to come out as the spacecraft each day gets closer to the comet. This image was taken from a distance of 825 miles, 375 miles closer than the previous day.

Very soon these close-up images will become too large to show the entire nucleus in one image. Rosetta will instead begin to snap images of specific features.

Meanwhile, the Rosetta science team released its first temperature readings of the comet.
» Read more

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Fermi proves that novae produce gamma rays

12:56 pm

The Fermi Gamma-Ray Space Telescope has discovered that novae, small scale stellar explosions similar to some supernovae but far less powerful, also produce gamma rays when they explode.

A nova is a sudden, short-lived brightening of an otherwise inconspicuous star caused by a thermonuclear explosion on the surface of a white dwarf, a compact star not much larger than Earth. Each nova explosion releases up to 100,000 times the annual energy output of our sun. Prior to Fermi, no one suspected these outbursts were capable of producing high-energy gamma rays, emission with energy levels millions of times greater than visible light and usually associated with far more powerful cosmic blasts.

What is significant about this is that it demonstrates a solid link between novae and supernovae, since only recently have scientists shown that some supernovae also produce gamma ray bursts. It suggests that the two explosions are produced by somewhat similar processes, but at very different scales. This fact will have important ramifications in the study of stellar evolution and the death of stars. For example, some nova stars often go nova repeatedly. Other data suggest that some more powerful eruptions can be recurrent as well. Extending this recurrent pattern to supernova suggests many new theoretical possibilities.

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How the Earth gave the Moon a lemon shape

9:36 am

Scientists have found that the Earth’s gravity combined with the Moon’s rotation forced the satellite to become “lemon-shaped.”

As the Moon solidified, its rotation caused it to elongate along its polar axis. But because the length of the Moon’s rotation was the same as its orbit, with one hemisphere always facing the Earth, the tidal force of the Earth’s gravity then pulled at the center, distorting the Moon’s shape so that one hemisphere bulged Earthward.

This theory is not new, but these new calculations are more robust, lending greater weight to it.

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The early bombardment of the Earth

9:04 am

Using computer models based on the Moon’s crater record, scientists have developed a simulation of the great early bombardment of the Earth around 4 billion years ago.

The model suggests that the biggest asteroids to hit Earth would have been as large as 3,000 kilometres across. Between one and four would have been 1,000 kilometres wide or larger, it predicts, with a total of three to seven exceeding 500 kilometres in width. The most recent of these would have hit around 4.2–4.3 billion years ago.

In comparison with Earth’s mass, the amount of rock hitting the planet would have been tiny. But it would have had an enormous effect on Earth’s surface, says Marchi. A 10-kilometre-wide asteroid was enough to kill the dinosaurs, and studies4 show that one 500 kilometres across would vaporize all of the planet’s oceans. “At 1,000 kilometres, the effects would be so wide the planet would probably be completely resurfaced with material from the mantle,” he says.

More here, including animated gifs showing this bombardment unfold.

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ExoMars will likely miss 2018 launch date

9:06 am

Because of technical and financial issues the European/Russian ExoMars rover mission is expected to miss its 2018 launch window.

The main reason for the delay would be the ExoMars’ brand-new landing system, which is designed to safely take the rover through a fiery descent in the Martian atmosphere and then softly land it on the surface of the Red Planet.

In addition to its late development start, the landing system has a complicated share of responsibilities between Russia and Europe, which greatly slows down the work. For example, the overall landing system is being developed by NPO Lavochkin in Moscow, while its parachute system will be provided by Europe. Many other aspects of the mission are similarly intertwined.

To further complicate matters, NPO Lavochkin, which traditionally builds all Russian planetary probes, but also some of the highly classified military satellites, is notorious for its Soviet-style secrecy. As a result, it is harder for the two sides to coordinate the work, Europeans sources said. Finally, the translation of documents between Russian and English further delays the work on the project.

The program is also significantly over budget.

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The Milky Way shrinks

9:49 pm

The uncertainty of science: New research by astronomers suggests that the Milky Way is about half as massive as previously estimated.

In the sixties I remember astronomers claiming that the Milky Way was twice as big as Andromeda. Then it was considered half as big. Most recently it was considered about the same size. This new research makes it half as big as Andromeda again.

In other words, the data is very uncertain, and the scientists really don’t have a good handle on it. None of these conclusions should be taken very seriously. All we really know at this point is that the Milky Way and Andromeda are approximately comparable.

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ISEE-3 engine restart fails but the private effort continues

11:57 am

After numerous tries, the private effort to put ISEE-3 back into its original orbit has failed.

We have completely accomplished all of our original goals except for one: firing the ISEE-3 propulsion system in a sufficient fashion to alter its trajectory. We did operate the propulsion system briefly so as to correct the spin of the spacecraft, and to start the trajectory correction maneuver. The propulsion system works fine. The problem is that there is no longer any Nitrogen pressurant left in its tanks to allow it to work.

36 years and more than 30 billion miles have taken its toll on the spacecraft’s propulsion system. We have exhausted every option to bring the engines online so as to conduct the correction maneuver required to place it in its planned orbit. Without the pressurant it just won’t work.

Have they given up? No! Though the spacecraft will remain in a solar orbit where maintaining communications will be difficult if not impossible, they are going to try anyway, and are even going to run another crowd-sourcing campaign to finance it.

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Gaia commissioning complete

9:47 am

After several months of in-orbit analysis, engineers have declared the European space telescope Gaia ready to begin research.

There have been several issues that had raised concerns, but from the article it sounds as if the engineers have either corrected the problems or have found ways to overcome or mitigate them.

Gaia will measure the movement and location of a billion stars, allowing astronomers to map the Milky Way better than ever before.

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Venus Express is alive

9:03 am

After diving into Venus’s atmosphere on an aerobraking test that could have destroyed the spacecraft, the European probe Venus Express has now successfully used its last bits of fuel to raise its orbit back to research height.

Its present orbit will probably decay sometime in December, when the spacecraft will burn up in the atmosphere. However, the scientists running the mission though that was likely to happen during the aerobraking maneuver. Instead, Venus Express is giving them about another half year of research.

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Planet of geysers

2:54 pm

Using Cassini data assembled over the past seven years, scientists have now identified 101 distinct geysers erupting on the surface of the Saturn’s moon Enceladus.

Over a period of almost seven years, Cassini’s cameras surveyed the south polar terrain of the small moon, a unique geological basin renowned for its four prominent “tiger stripe” fractures and the geysers of tiny icy particles and water vapor first sighted there nearly 10 years ago. The result of the survey is a map of 101 geysers, each erupting from one of the tiger stripe fractures, and the discovery that individual geysers are coincident with small hot spots. These relationships pointed the way to the geysers’ origin.

The really important discovery here however is this:
» Read more

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Protecting the Mars orbiters from comet flyby

4:10 pm

Engineers are repositioning the American spacecraft orbiting Mars so that they will be better protected by the planet when Comet Siding Spring flies past on October 19.

The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.

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The loss of skepticism in science

3:19 pm

In April I taped a half hour television interview with George Noory for his subscription-based video show, Beyond Belief. Below is a clip from that interview, where I describe the terrible state of climate research, and how politics is destroying the very heart of what science stands for. Too many people are no longer open-minded. Rather than relay on the data they push their theories instead.

Robert Zimmerman discusses the truth about climate change with George Noory!

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Russia loses contact with Photon-M

9:06 am

Russia has lost contact with its Photon-M biology spacecraft, launched last week with a four geckos on board.

The Russians say that the receipt of telemetry from the spacecraft shows it is successfully operating autonomously without help from the ground. And since the Russians have a great deal of experience building spacecraft that can function on their own, I have no reason to disbelieve them in this. What is not clear is whether the spacecraft can come home on its own.

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Exoplanets with no water

6:43 pm

The uncertainty of science: Though planet formation theories said they should have water, in looking for water on three exoplanets astronomers were surprised to discover practically none there.

The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor. These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.

“Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we’ve found water in an exoplanet,” said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. “However, the low water abundance we have found so far is quite astonishing.” Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. “It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they’re formed.”

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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.

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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.

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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.

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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.

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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.

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