SCIENCE MATTERS: CLOSE CALL (OR HOW 2004-BL86 ALMOST PAID EARTH A VISIT)

Picture of the Asteroid Ida and its Moon

By David Dannecker
Senior Editor

On Monday, January 26 this week, Earth had a close call with the asteroid 2004 BL86. Late Monday morning, the asteroid in question passed by our planet at a distance of just 1.2 million kilometers. That’s only three times further from the Earth than the Moon’s orbit, and plenty close enough for the asteroid to be seen through an average telescope. This particular asteroid is about 300 meters in diameter and has a small moon of its own, judged to be between 50 and 100 meters in diameter. No asteroid this big is expected to pass as close to Earth for the next 12 years, so Monday’s event is notable.

Luckily, 2004 BL86 was only passing through the neighborhood, and we avoided an actual impact. But what would the consequences have been if there had been a collision on Monday? And how does this asteroid compare to the other asteroids that populate our solar system?

At 300 meters in diameter, 2004 BL86 pales in comparison to the asteroid that is thought to have been responsible for the K-T mass extinction event that wiped out the dinosaurs. That asteroid is estimated to have been 10 to 12 kilometers in diameter, or at least 33 times further across than Monday’s interloper (and significantly more massive, as volume scales faster than length). Collisions with asteroids on that scale are far more likely to cause mass extinctions, since the impacts are so powerful as to have global consequences. The roughly 10 kilometer asteroid left behind a crater 100 kilometers in diameter and scattered iridium-rich sediment around the globe. Earth would not have been at risk of repercussions on that scale if 2004 BL86 had collided on Monday. Asteroids larger than 10 kilometers are not actually that common in the solar system; out of the tens of millions of asteroids that orbit the Sun, only about 12,000 are larger than 10 kilometers in diameter, and astronomers believe we have identified 94 percent of the asteroids at that scale.

2004 BL86 falls into a category of more average asteroids that are a few hundred meters in diameter. This category includes many of the millions of asteroids that have been discovered, and likely many more that have yet to be noticed. What effects might a collision with an asteroid of this scale produce? While not causing the widespread devastation of larger asteroids, according to National Geographic, asteroids of this middle size would still be fairly catastrophic, devastating whatever region they impacted and potentially destroying entire nations. Given that assessment, we should consider 2004 BL86’s flyby extremely fortunate. Even more fortunate, collisions of that scale are only believed to occur once every half a million years. In addition to these average-sized asteroids, there are millions and millions of smaller, harder-to-detect asteroids that are in the range a few meters to a few dozen meters, only the largest of which would avoid burning up in the atmosphere. Many readers might recall the meteor that exploded over Russia in 2013; that object was about 18 meters in diameter, and while it didn’t impact the Earth’s surface, the explosion was enough to cause over a thousand injuries.

But what are asteroids doing in Earth’s neighborhood anyway? It is true that the highest concentration of asteroids is found in the main asteroid belt that lies between the orbits of Mars and Jupiter. These asteroids would likely have coalesced into a planet in that orbital region long ago, were it not for Jupiter’s immense gravitational influence. Besides the belt asteroids however, there are other asteroids whose regular orbits are dispersed throughout the solar system. A belt of asteroids known as Near Earth Asteroids (NEAs) exists in the vicinity of Earth’s orbit. This belt consists of approximately 12,000 asteroids one meter or larger, of which fewer than 1,000 are larger than one kilometer in diameter. These asteroids tend to orbit for a few million years before colliding with the Sun, colliding with a planet, or being slingshotted out of the solar system altogether. Given that NEAs have such a short lifespan, it’s generally believed that a gradual, but constant, supply of asteroids is nudged out of the main asteroid belt by way of gravitational interactions with Jupiter. So as it turns out, Jupiter’s orbital dynamics are responsible for both the main asteroid belt, and our own smaller belt of NEAs.

Despite the apparently constant stream of NEAs being thrown Earth’s way, astronomers are fairly sure of the low probability of a significant impact. Large extraterrestrial objects are searched for, identified and tracked long before they cross paths with Earth, so the general wisdom suggests we would know a collision was coming long before its arrival; “Armageddon”-style scenarios, where Texas-sized asteroids are noticed with only 18 days to prepare, are incredibly unlikely (especially considering there is literally only one asteroid that large in the entire solar system, and we know where it is). As mentioned, 2004 BL86’s passage is the closest call we’ll have until 2027, when the asteroid 1999 AN10 will pass by Earth on schedule. So humanity can rest easy this week, and probably every week, since astronomers are constantly scanning to find asteroids before they find us. Newer and better telescopes are being constructed. Events like 2004 BL86’s passing give astronomers the chance to observe asteroids up close to learn more about their behavior, and new technologies may aid in the search even further. But with millions of asteroids out there, thank goodness humans have a fascination with watching the skies.

Image by NASA APPEL

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SCIENCE MATTERS: THE POWER OF VITAMINS

Vitamin supplements

By Aarushi Gupta
Staff Writer

Vitamins have become a booming industry in recent years. Businesses like The Vitamin Shoppe and Nature Made have made millions by isolating specific vitamins and minerals necessary for metabolic activity. However, recent studies have shown that an excess of certain vitamins may not only be unnecessary, but also harmful. In 2014, Nature published a piece which summarized the debate among scientists and health professionals regarding the use of vitamins in society, and several studies have shown that vitamins have no significant health benefit in terms of fighting cardiovascular disease or cancer.

Vitamins are organic compounds that organisms, such as humans and other animals, require to survive. Many vitamins cannot be made by the organism, and therefore must be obtained from the diet. They are often present as assistant molecules in metabolic pathways such as sugar breakdown and fatty acid biosynthesis. Historically, several diseases like scurvy and beriberi have been associated with vitamin deficiencies, and treatment of these ailments with vitamin supplements led scientists and medical professionals to believe that several disorders like cancer or heart disease could be cured with vitamins. Research has shown that in developed countries like the United States, nutrient supplements had almost no health effects or benefits.

While vitamins stand to benefit inhabitants of many developing nations where cases of malnourishment are common, the United States has long touted its own battle with the condition. Because so many foods are fortified with vitamins, the natural nutritional value of several foods has decreased, leading to malnutrition as well as obesity in the United States. This seems counterintuitive, but the best way to eradicate hunger issues in the United States is through consuming fresh fruits and vegetables and as nutrition professor Joanne Slavin says, “getting closer to production” by growing produce.

Scientists believe that vitamins are only needed in small amounts, and an excess of vitamins and other supplements can be ineffective or lead to further health problems. However, this is only true for a few supplements, like vitamin E, A, and C. Excesses of other vitamins are simply released in urine, which is a popular weakness of vitamin supplements. According to David Agus, physician and best-selling author of “The End of Illness”, Americans spend $28 billion per year in dietary supplements, including both vitamins and herbals. Researchers at Johns Hopkins University have gone so far as to propose that the US cease producing vitamin supplements, because most of the money and the resources go to waste.

In fact, several trials conducted by the Alpha-Tocopherol Beta-Carotene Cancer Prevention Group were conducted to determine if vitamin additives could help the overall health of smokers. Interestingly enough, participants who consumed more B-carotene than necessary over five to eight years were 18 percent more likely to develop lung cancer. Because vitamins are involved with various kinds of primary and secondary metabolism, an overdose can lead to increased cell growth. In some cases, this cell growth can be uncontrollable and lead to cancer, depending on the individual.

Vitamins have shown their obvious potential when it comes to combating malnourishment in third world countries as well as diseases associated with the condition. Maybe citizens of the United States and other developed nations should cut back on vitamin production and spread proper information regarding nutrition and healthy choices in schools and workplaces.

Image by Shannon Kringen

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SCIENCE MATTERS: FACT-CHECKING KEYSTONE XL

Segment of TransAlaskan Pipeline near Fairbanks

By David Dannecker
Senior Editor

The Keystone XL pipeline extension has been back in the news recently, thanks in part to an effort by Senator Mary Landrieu (D-LA) to hold a Senate vote on the project last month which ultimately failed by a razor-thin margin. For those who don’t know, the pipeline first proposed back in 2008 would run from Alberta to Nebraska, delivering crude oil from Alberta’s tar sands to refineries on the Gulf Coast. The project has been a major point of contention between environmentalists and the Canadian petrochemical company TransCanada since its first proposal. Polling suggests that the proposal enjoys majority support among Americans, although support has been slipping since a high about a year and a half ago. With the special interest proxy war in its seventh year, it is hard to get a handle on what the actual facts are surrounding Keystone XL and what effects it would have if it received the green light for construction. It seems that the level of misinformation in the debate could be a confounding factor when it comes to gauging public support; very few people are likely to know the details of the project, especially those that haven’t been following the issue. Figures for job creation vary wildly, as do claims about its safety, and the broader environmental impact the project could have. So without further ado, let’s delve into some of the arguments over Keystone XL.

Job creation is one of the primary arguments in favor of the pipeline. It’s true that infrastructure projects often are a big help toward creating jobs and spurring economic growth. However, reports of the number of jobs that Keystone XL could create are inconsistent. The figures on TransCanada’s website suggest an estimate of 9,000 construction jobs for the project, while other sources suggest a more modest 2,000 construction jobs, with those positions only lasting a couple of years. The State Department found that the number of permanent jobs created by Keystone XL (i.e. those jobs that would outlast the construction phase of the project) would equal a paltry 50 employees. To put those figures in some kind of context, the United States as a whole added 214,000 jobs in the month of October this year. Even the higher job estimates cited by TransCanada represent less than five percent of one month’s national job growth. If job creation is the main reason behind Republican support for the project, one has to wonder why other infrastructure initiatives with ostensibly greater job creation potential often meet with tepid Republican support at best.

Turning to claims about the pipeline’s safety, TransCanada appears confident that the new branch of the Keystone pipeline will be the safest ever constructed. Seeing as the new pipeline will have the benefit of the last few years of cutting edge technological advancements that weren’t available to the earlier phases of the pipeline, this may be the case. However, Media Matters points out that in spite of similar language before the original Keystone pipeline, it suffered a dozen spills in just its first year. Oil pipelines have a poor track record in the U.S. in general with over 110 million gallons spilled in the last 25 years. And while the pipeline has been rerouted to avoid the environmentally sensitive Sandhills area of Nebraska, the new route still threatens drinking water, including crossing an important aqueduct, which would be vulnerable to contamination should a spill occur in the vicinity. TransCanada has assured the public that it is committed to containment and restoration in the event of any spills or leaks, but even so, given the history of pipeline shortcomings and TransCanada’s own recent record of overselling the safety of its delivery infrastructure, treating safety claims with some modest skepticism seems appropriate.

What about the environmental impact of Keystone XL? Would it be the harbinger of climatic doom that environmentalists have painted it to be? Firstly, tar sands are one of the least efficient sources for obtaining fossil fuels. Because the crude oil is found in an amalgam of sand, clay, and bitumen, extraction is extremely difficult. The extraction process itself requires a great deal of natural gas and water to isolate the crude oil, and that’s before the transportation and refinement processes. So, yes, tar sands as a fuel source are pretty awful for the environment, and that’s not even taking into account the significant deforestation connected with mining tar sands. Some defenders of Keystone XL argue that Alberta’s tar sands are going to be utilized with or without Keystone, so the pipeline itself should be seen as a net zero as far as emissions go. It’s true that TransCanada is exploring other options for delivering the crude oil to refineries, including sending the oil by rail or by retrofitting Canadian pipelines to handle crude oil in a separate project known as Energy East. However, rail transport has been under increased scrutiny in the aftermath of a couple of explosive disasters, and neither of these alternatives would be as cost-effective as Keystone XL would be for TransCanada, which explains their dogged determination to see the proposal approved. Given the opposition that each of these approaches is facing, the development of Alberta’s tar sands is no sure thing. The value of extraction relies on the possibility and ease of subsequent transport, so while Keystone XL isn’t the only option Canadian energy companies have, its existence would likely facilitate and foster future development.

While disagreements over the merits of Keystone XL continue to exist, and are likely to persist until the project is either approved or denied for good, it is possible to isolate some plausible parameters to frame the debate. Sourcing tar sands for crude oil is bad for the environment. While Keystone is not the only option for crude oil delivery, it would likely speed up tar sand development in Alberta and so hasten the release of their greenhouse gases. The prospects for Keystone job creation are not likely to be very significant, and there are plenty of non-fossil-fuel-related infrastructure alternatives to consider if temporary job creation is the goal. It’s hard to predict the exact likelihood of pipeline malfunctions, since accidents are by their very nature unpredictable, but the position of the pipeline route and the recent history of pipeline technology do not support the idea that Keystone XL would be as safe as TransCanada claims. As the facts surrounding this project find their way into the public debate, we might expect that the polls will continue to decline. President Obama has recently signaled his own awareness of the project’s shortcomings. While the proposal itself is tied up while a legal challenge is settled in Nebraska’s Supreme Court, Obama’s opposition to Keystone XL looks like it will be the deciding factor, even in the face of a new Republican-controlled Congress. Since Canadian oil companies are the only certain beneficiaries of Keystone XL’s construction, the project seems unlikely to move forward, what with Obama positioning climate change as one of the defining issues of the final years of his presidency.

Image by Maureen

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