The first solar eclipse of 2014 will occur in conjunction with the new moon on Tuesday, April 29 at 2:14 a.m. EDT. The event will mainly be visible from parts of Australia and Antarctica, but fear not! Those of us in other parts of the world can still catch all the action via Slooh’s live webcast; coverage begins at 2:00 a.m. EDT. The lunar disk will partially cover the sun over Australia, resulting in a partial solar eclipse. Partial solar eclipses can be observed when only the lunar penumbra (the partially shaded outer region of the shadow cast by an object) touches the Earth. Further south, a lopsided annular “Ring of Fire” eclipse will occur near the horizon for a small, uninhabited part of Antarctica. Penguins will likely be the only ones to enjoy front-row seats to the sky spectacle. Annular eclipses occur when the Moon appears smaller than the Sun as it passes centrally across the solar disk and a bright ring, or annulus, of sunlight remains visible around the moon’s silhouette. The best view of the eclipse will be from the island state of Tasmania.
The maximum number of solar eclipses (partial, annular, or total) that can occur in a given year is five, and there are at least two solar eclipses per year somewhere on the earth. In 2014, we will see two solar eclipses with the second one occurring on October 23rd. For viewing information, consult this NASA map showing the shadow path of the solar eclipse. The chart, prepared by NASA eclipse expert Fred Espenak, also lists times for maximum eclipse.
Remember never to look directly into the sun without using astronomical-grade solar filters; permanent eye damage can result.
A Penn State University astronomer, Kevin Luhman, has discovered a brown dwarf star that appears to be the coldest of its kind–as cold as the North Pole–using NASA’s Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes. The newfound star, named WISE JO85510.83-071442.5, is only 7.2 light years away, making it the fourth closest system to our sun. The object has a temperature between negative 54 and 9 degrees Fahrenheit. Previous record holders for coldest brown dwarfs were around room temperature.
Despite their name, brown dwarfs can be a number of different colors. Brown dwarfs were first hypothesized in 1963 by American astronomer Shiv Kumar who initially called these bodies “black dwarfs” since they were not very luminous at visible wavelengths and instead appear brightest in the infrared range. However, this term was already taken to refer to cold white dwarfs, so American astronomer Jill Tarter proposed the name “brown dwarf” in 1975 because these objects were thought to contain dust. Brown dwarfs begin their lives as collapsing balls of gas like other stars, but they lack the mass necessary to sustain hydrogen fusion reactions and radiate starlight.
WISE JO85510.83-071442.5 is estimated to be 3 to 10 times the size of Jupiter, a fact that raises questions about its categorization. Because some definitions of brown dwarfs require objects to be at least ten times the mass of Jupiter, the new star may be demoted in the future, just as Pluto was. However, scientists predict the object is most likely a brown dwarf rather than a gas giant planet since brown dwarfs are known to be fairly common.
If you’re running on Chrome browser, check out Google’s latest Experiment project – it visualizes the precise location of at least 100,000 stars in our Milky Way galaxy, using various imagery and data pulled from NASA and the European Space Agency (ESA). For a frame of reference, there are approximately 200 to 400 billion stars in the Milky Way galaxy.
April 20th-26th is International Dark Skies Week. How does your sky look on a clear night? Check out this website for tips on how to light responsibly.
TTR amyloidosis is a rare hereditary disease characterized by abnormal production of a protein called transthyretin, or TTR, which is responsible for shuttling the thyroid hormone thyroxine (T4) and retinol (an animal form of vitamin A) around the body. Hence, the name transthyretin: transports thyroxine and retinol. The defective version of the protein is unable to perform its task and ends up getting lodged in the nerves and heart, forming insoluble clumps known as amyloid deposits.
In the beginning, this kind of damage may lead to loss of physical sensation, and some patients even become bedridden. As the disease progresses, the amyloid deposits may damage the nerves that are responsible for processes such as digestion, giving rise to a multitude of symptoms, including diarrhea, vomiting, constipation, and low blood pressure.
Transthyretin is produced in the liver, so in 1990, physicians began offering patients with the disease liver transplants. However, this strategy wasn’t terribly effective. Liver transplants are difficult to come by, and for many patients this approach fails to produce the intended results. In recent years, researchers have developed two stabilizing drugs–diflunisal and tafimidis, which are intended to keep the abnormal TTR from misfolding. Both drugs do seem to slow the progression of the disease, but neither constitute a cure.
According to an article published by NOVA Next, researchers are now working to develop a class of medicines aimed at accomplishing what no other therapies have before: silencing the TTR gene. Rather than merely treating the symptoms of TTR amyloidosis, this therapy will tackle the root of the problem by blocking production of the problematic protein. In 1998, Andrew Fire and Craig C. Mello took a major step towards this approach while working with the nematode worm C. elegans. They discovered the double-stranded RNA could trigger gene silencing. They called this process RNA interference, or RNAi. The pair won the 2006 Nobel Prize in Physiology or Medicine for their innovative work.
In the following years, researchers began to uncover the mechanisms behind this promising process. In order to produce a protein, cells require messenger RNA, which carries instructions for the production of proteins to the ribosomes in a cell’s cytoplasm. Double-stranded RNA, however, disrupts this process. Upon encountering dsRNA, enzymes called dicers slice the dsRNA into small chunks around 20 nucleotides long. Next, these double-stranded bits, known as small interfering RNAs (siRNAs), bind to a class of proteins called Argonautes. The Argonautes can then seek out mRNA with a complementary base sequence and slice these mRNA strands, rendering them useless. Without mRNA, a cell cannot produce proteins. The siRNAs have the ability to bind to Argonautes multiple times, so a single siRNA molecule can effectively destroy hundreds of mRNA molecules within a cell.
Conventional drugs attack a protein by binding to them, but many proteins lack a good active site. Out of more than 100,000 proteins that the body is capable of producing, researchers have only been able to target a few hundred. RNAi offers a single method to block all of them. In 2002, Philip Sharp, a Nobel laureate and molecular biologist at the Massachusetts Institute of Technology in Cambridge, teamed up with scientists involved in the early development stages of RNAi to launch Alnylam, the first company aimed at developing RNAi therapies. John Maraganore, CEO of Alnylam, says, “With RNAi we can stop a flood by turning off a faucet. Small molecules can only mop up the floor.”
In July 2010, Alnylam launched the first human study to test the efficacy of its therapy for TTR amyloidosis, an siRNA wrapped in a lipid nanoparticle. Participants received a single dose, and the initial results were promising. In 2012, the company launched another study to test the safety of the drug and its impact on TTR production. One dose of the medicine ended up inhibiting TTR production by as much as 94%. Last winter, Alnylam launched a phase III clinical trial. The 18-month study is aimed at examining whether the medication has any impact on the participants’ nerve function. One group will receive a saline solution and the other group will be administered the drug, called partisiran. Because partisiran and other RNAi therapies depend on lipid nanoparticles, they must be administered via an IV.
Partisiran is the first RNAi therapy to enter a phase III clinical trial and may become the first RNAi therapy on the market. But RNAi offers hope for developing therapies that extend far beyond amyloidosis. Alnylam is currently working on developing therapies for seven other diseases, including hemophilia and high cholesterol. And other companies are developing siRNAs to treat everything from ebola to liver cancer. However, even if partisiran succeeds, the drug will not be widely available for the next several years. Alnylam won’t have the results of the phase III trial until 2017.
April 22nd marks Earth Day, the annual U.N.-sponsored event to celebrate our planet and raise awareness of the impact that human activity has on our environment. TheWorldPost looks into some of Earth’s natural wonders that face the possibility of destruction. Additionally, the Huffington Post has captured the incredible diversity of Earth’s biomes landscapes in a beautiful collection of photos, as well as a set of 22 technicolor dreamscapes of actual places in nature.
NOVA has written about online crowdsourcing as a means to solve complex global challenges. The MIT Center for Collective Intelligence has created the Climate CoLab, an online platform where people from around the world collaborate on issues involving global climate change. In the past, crowdsourcing has often lead to fruitful results, from Wikipedia to open source software to the online game FoldIt, in which players from around the world helped produce an accurate model of a essential protein found in an HIV-like virus in just ten days, solving a problem that had confounded scientists for 15 years. The developers of Climate CoLab hope that their initiative will do for climate change what FoldIt did for chemistry. Anyone, regardless of background or expertise, can contribute to Climate CoLab, and a person’s work can be reviewed by an international community of people-including experts from NASA, the World Bank, and leading universities like Stanford and Colombia.
In honor of Earth Day, Phil Plait has compiled a list of fun factoids about Earth. SoulPancake has created a garden of gratitude. Additionally, for every shirt sold in their store in April, the I Love Science Store will be donating the money to plant ten trees. 100 shirts=1,000 trees. It’s a great day to be an inhabitant of Earth!