Tag Archives: science

Astronauts lose about half their muscle power on long space flights

Though this only confirms what the Russians learned on Mir, scientists have determined that long periods in weightlessness cause a significant loss in muscle strength. More research like this — to both study the problem as well as possibly solve it — is exactly what we need to do on ISS. Key quote:

Damage caused to the tissue is such that it is equivalent to a 30- to 50-year-old crew member’s muscles deteriorating to that of an 80-year-old. Despite in-flight exercise, the report warns that the destructive effects of extended weightlessness to skeletal muscle poses a significant safety risk for future manned missions to Mars and further afield.

Share

Not a black hole?

European scientists, using the Very Large Telescope at the European Southern Observatory, have determined that a magnetar (a neutron star pulsar with an extremely strong magnetic field) was formed from a star with a mass 40 times that of the Sun. This is a significant discovery, as most theories say that any star this heavy should instead become a black hole when it dies. That this particular star instead became a neutron star challenges present astronomical theory.

Share

Old Media, Old News

The New York Times today published an op-ed outlining the serious dangers we face should the Sun unleash a solar flare or coronal mass ejection of sufficient power to knock out our electrical grids. After describing the horrors of Hurricane Katrina, the author then says

We are similarly unready for another potential natural disaster: solar storms, bursts of gas on the sun’s surface that release tremendous energy pulses.

Now this might be interesting, had it been published in 1988. At that time, the electrical grids used in the U.S. and Canada were very much unprepared for a sudden solar storm. Moreover, the Sun at that time was ramping up towards a particularly active solar maximum. The result: On March 13, 1989, the power grid that supplied electricity to Quebec and 200 utility companies in the U.S. came crashing down, overloaded by a power surge caused by a burst of energy sent hurtling towards the Earth, by the Sun.

However, to report this threat today as if it was news is somewhat laughable. Since the 1990 solar maximum, the world’s electrical systems have been very much aware of the problem and have instituted numerous safeguards should the Sun burp at them again. It was for this reason that there were few problems during the next solar maximum in 2001, even though it was almost as powerful as the maximum in 1990.

The real news story concerning the Sun is how inactive it has been, for reasons scientists do not understand. Not only was the recently concluded solar minimum the longest and deepest in almost a hundred years, the subsequent solar activity leading to the next solar maximum has been far weaker than every prediction. At the moment, the Sun appears headed for the weakest solar maximum in two hundred years. And when that last happened, the Earth experienced a period of significantly cold weather, also for reasons that scientist do not yet understand.

It is this story that journalists should be covering.

the solar cycle

Share

More questions raised about Mann’s hockey stick graph

A new research paper, written by statistical scientists and to be published next month in the Annals of Applied Statistics, has found that Michael Mann’s hockey stick graph, showing a steep increase in global temperature in the last two hundred years, is statistically invalid. Key quote:

Research on multi-proxy temperature reconstructions of the earth’s temperature is now entering its second decade. While the literature is large, there has been very little collaboration with university level, professional statisticians (Wegman et al., 2006; Wegman, 2006). Our paper is an effort to apply some modern statistical methods to these problems. While our results agree with the climate scientists findings in some respects, our methods of estimating model uncertainty and accuracy are in sharp disagreement.

[We] conclude unequivocally that the evidence for a ”long-handled” hockey stick (where the shaft of the hockey stick extends to the year 1000 AD) is lacking in the data. The fundamental problem is that there is a limited amount of proxy data which dates back to 1000 AD; what is available is weakly predictive of global annual temperature. Our backcasting methods, which track quite closely the methods applied most recently in Mann (2008) to the same data, are unable to catch the sharp run up in temperatures recorded in the 1990s, even in-sample. [emphasis mine]

In other words, the temperature data going back to 1000 AD is poor, and cannot be reliably used to prove a sudden increase in global temperature in the last two hundred years. More importantly, according to this paper, Michael Mann tried to use statistics to prove his point, without consulting any statisticians.

Share

Sloppy journalism from the BBC

Though solar scientists have discovered that certain recent solar behavior might help explain the long and deep solar minimum that just ended, this BBC article immediately tries to give that result credit for explaining everything. To quote:

Solar physicists may have discovered why the Sun recently experienced a prolonged period of weak activity.

NOT! The result only observed a change in solar behavior beneath the surface, whereby the meridional flow slowed down as well as lengthened significantly into the high latitudes, and that this change occurred at the same time as the weak solar minimum. The paper made no attempt to explain why this happened, nor did it provide a theoretical explanation for how these changes resulted in a weak solar minimum.

Finally, and far more important, scientists still have no good theory for explaining the solar cycle in the first place. “We think it’s the solar dynamo [that causes the solar cycle],” noted Dean Pesnell of the Goddard Space Flight Center when I interviewed him for my Sky & Telescope article, What’s Wrong with Our Sun? (August 2009). “But we don’t undertand how the dynamo works, as yet.”

The BBC should be more careful in how it reports a story like this.

Share

A possible cause of extended solar minimum proposed

Scientists think they have discovered at least one cause of the recent long and deep solar minimum: a change in how plasma near the surface of the Sun flows from the equator to the pole, sinks, and then flows back to the equator. In the last minimum, this meridional current flowed much slower, while also flowing much closer to the pole before finally sinking.

Share

Is it a planet or not?

An object, initially announced in 1998 to be the first planet ever photographed, then rejected as a planet when data suggested it was too hot, is now being resurrected as a possible planet. Key quote by Adam Burrows of Princeton University:

[If true] this would punctuate one of the strangest episodes in the history of the emerging field of exoplanet research. If false, it would be one more warning that numerous pitfalls await the intrepid astronomer in search of planetary gold beyond the solar system.

Share

Diversifying your research portfolio

In this paper [pdf] adapted from a lecture he gave at an astronomy conference, Harvard researcher Abraham Loeb warns young scientists that their tendency today to take on safe research projects is unwise. Moreover, he notes the increasing “herd mentality” due to “stronger social pressure”, “more competition in the job market,” and the “growing fraction of observational and theoretical projects . . . done in large groups with rigid research agendas and tight schedules.” Key quote:

It is always prudent to allocate some limited resources to innovative ideas beyond any dogmatic “mainstream,” because even if only one out of a million such ideas bears fruit, it could transform our view of reality and justify the entire effort. This lesson is surprisingly unpopular in the current culture of funding agencies like NSF or NASA, which promote research with predictable and safe goals.

Share

Hubble image of face-on galaxy

Another spectacular Hubble Space Telescope image was released today, showing a face-on spiral galaxy in the Coma cluster, located about 320 million light years away. Key quote:

The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes.

NGC 4911

Share

Robot to explore Egyptian pyramid

British engineers/scientists are about to send a robot into the Great Pyramid at Khufu in Egypt to find out what lies hidden behind the doors at the end of two 200 foot long shafts. Fun quote:

No one knows what the shafts are for. In 1992, a camera sent up the shaft leading from the south wall of the Queen’s Chamber discovered it was blocked after 60 metres [200 feet] by a limestone door with two copper handles. In 2002, a further expedition drilled through this door and revealed, 20 centimetres [8 inches] behind it, a second door.

“The second door is unlike the first. It looks as if it is screening or covering something,” said Dr Zahi Hawass, the head of the Supreme Council who is in charge of the expedition. The north shaft bends by 45 degrees after 18 metres [60 feet] but, after 60 metres, is also blocked by a limestone door.

Share

Aqua tracks carbon monoxide over Russia from wildfires

Data from the AIRS instrument on NASA’s Aqua satellite shows the dramatic increase in carbon monoxide in the atmosphere at 18,000 feet over Russia due to the wildfires there. Key quote from press release:

The concentration of carbon monoxide is continuing to grow. According to Aug. 4 NASA estimates, the smoke plume from the fires spans about 3,000 kilometers (1,860 miles) from east to west.

Share

Mapping daylight at the Moon’s South Pole

Using data from the Japanese lunar orbiter Kaguya, scientists have identified several locations near the Moon’s south pole that are in daylight from 86 to 94 percent of the time. Key quote from abstract:

The place receiving the most illumination (86% of the year) is located close to the rim of Shackleton crater at 88.74°S 124.5°E. However two other areas, less than 10 km apart from each other, are collectively lit for 94% of the year. We found that sites exist near the south pole that are continuously lit for several months during summer. We were also able to map the locations and durations of eclipse periods for these areas. Finally we analyzed the seasonal variations in lighting conditions, from summer to winter, for key areas near the south pole. We conclude that areas exist near the south pole that have illumination conditions that make them ideal candidates as future outpost sites. [emphasis mine]

Below is a composite close-up image of the rim of Shackleten crator that I assembled using this Lunar Reconnaissance image. The key quote from the full caption :

The full [Narrow Angle Camera] mosaic reveals a shelf on the southeast flank of the crater that is more than two kilometers across and perfectly suitable for a future landing. The extreme Sun angle gives the surface an exaggerated rough appearance, but if you look closely at this scale any area that is between the small craters might make a good landing site.

Rim of Shackleton Crater

Share

Scientists have plans to go to killer asteroid

Talk about thinking ahead! Since 2007 a team of scientists have actually been planning a mission to 1999 RQ36, the asteroid that has a 1 in 1000 chance of hitting the Earth in 2182. Their mission, dubbed OSIRIS-Rex (Origins Spectral Interpretation Resource Identification Security Regolith Explorer), has already been picked as one of two finalists in NASA’s New Frontiers program. The decision on which mission NASA will fund will be made next summer.

Share

Bat extinctions

An article today in Science describes how scientists now believe that white nose syndrome is probably going to cause the extinction of the little brown myotis bat. Key quote from the press release:

The researchers determined that there is a 99 percent chance of regional extinction of little brown myotis within the next 20 years if mortality and spread of the disease continue unabated. They note that several other bat species may also face a similar risk.

Share

Melting Ice on Mars?

These Mars Reconnaissance Orbiter images show in increasing magnification a puzzling feature in the southeast part of a ice mound in Louth Crater on Mars. Located at 70 degrees north latitude, this is the farthest south that scientists have found permanent water ice. The close-up image suggests melting ice with the draining water running down hill to the south, though on Mars the low air pressure would cause any liquid water to evaporate instantly. Key quote:

These may be the crests of partially defrosted dark sand dunes or perhaps some other feature that we do not understand. This is the only area on Louth where these enigmatic ridges are found.

wide view of crator mound

Middle view of ice mound

Closeup of ice mound

Share

A ground-based telescope matches the Hubble Space Telescope-NOT

Correction.Regular reader James Fincannon emailed me to say that he thinks the image below is an artist’s impression. He is correct. I should have looked more closely at the press release. In reading the actual research paper [pdf] on the results it seems that the VLT did some very sophisticated spectroscopy, thereby measuring the uneven distribution of the velocity and density of the gas around the star. The image below was then created, based largely on Hubble images combined with the new data. In other words, this ground-based telescope did not match the abilities of a space-based telescope in any way. Had the Hubble images not existed the astronomers would have struggled to interpret their spectroscopic data.

Some important astronomy news: The European Southern Observatory’s Very Large Telescope (VLT) has released this spectacular image of supernova 1987a, the first and so far only supernova visible to the naked eye since the invention of the telescope.

SN1987a

This image is important for two reasons. First, The data shows that the supernova explosion was not symmetrical, with more material being thrown outward in some directions than in others. This fact confirms what astronomers in recent years have increasingly come to believe: Supernovae explosions are not simple spherical bursts, but chaotic events ripping stars apart in a lopsided manner.

Second, this image demonstrates that ground-based telescopes are becoming amazingly good at doing what the Hubble Space Telescope has done routinely for the past two decades. Five years ago, no telescope on the ground could have resolved the inner ring of supernova 1987a. Only Hubble in space had that capability. Now, VLT can do it, almost as well as Hubble. Though a space-based telescope can still beat any ground-based telescope, it is great news that the technology for ground-based telescopes has improved so much, especially since there presently are no plans to replace Hubble.

Share

Tunnel and tombs in Mexico

Archeologists have uncovered a previously unknown tunnel and several chambers under the Temple of Quetzacoatl north of Mexico City. Key quote:

Experts say a tomb discovery would be significant because the social structure of Teotihuacan remains a mystery after nearly 100 years of archaeological exploration at the site, which is best known for the towering Pyramids of the Moon and the Sun. No depiction of a ruler, or the tomb of a monarch, has ever been found, setting the metropolis apart from other pre-Hispanic cultures that deified their rulers.

Share
1 157 158 159 160 161 162