Science Over the Edge

A Roundup of Strange Science for the Month

Sept/October 2019

In the News:

Hints Of A Volcanically Active Exomoon - Jupiter's moon Io is the most volcanically active body in our solar system. Today, there are indications that an active moon outside our solar system, an exo-Io, could be hidden at the exoplanet system WASP-49b. "It would be a dangerous volcanic world with a molten surface of lava, a lunar version of close-in Super Earths like 55 Cancri-e" says Apurva Oza, postdoctoral fellow at the Physics Insitute of the University of Bern and associate of the NCCR PlanetS, "a place where Jedis go to die, perilously familiar to Anakin Skywalker." But the object that Oza and his colleagues describe in their work seems to be even more exotic than Star Wars science fiction: the possible exomoon would orbit a hot giant planet, which in turn would race once around its host star in less than three days - a scenario 550 light years away in the inconspicuous constellation of Lepus, underneath the bright Orion constellation. Astronomers have not yet discovered a rocky moon beyond our solar system and it's on the basis of circumstantial evidence that the researchers in Bern conclude that the exo-Io exists: Sodium gas was detected at the WASP 49-b at an anomalously high-altitude. "The neutral sodium gas is so far away from the planet that it is unlikely to be emitted solely by a planetary wind," says Oza. Observations of Jupiter and Io in our solar system, by the international team, along with mass loss calculations show that an exo-Io could be a very plausible source of sodium at WASP 49-b. "The sodium is right where it should be" says the astrophysicist. Already in 2006, Bob Johnson of the University of Virginia and the late Patrick Huggins at New York University, USA had shown that large amounts of sodium at an exoplanet could point to a hidden moon or ring of material, and ten years ago, researchers at Virginia calculated that such a compact system of three bodies: star, close-in giant planet and moon, can be stable over billions of years. Apurva Oza was then a student at Virginia, and after his PhD on moons atmospheres in Paris, decided to pick up the theoretical calculations of these researchers. He now publishes the results of his work together with Johnson and colleagues in the Astrophysical Journal. "The enormous tidal forces in such a system are the key to everything," explains the astrophysicist. The energy released by the tides to the planet and its moon keeps the moon's orbit stable, simultaneously heating it up and making it volcanically active. In their work, the researchers were able to show that a small rocky moon can eject more sodium and potassium into space through this extreme volcanism than a large gas planet, especially at high altitudes. "Sodium and potassium lines are quantum treasures to us astronomers because they are extremely bright," says Oza, "the vintage street lamps that light up our streets with yellow haze, is akin to the gas we are now detecting in the spectra of a dozen exoplanets."

New Artifacts Suggest People Arrived In North America Earlier Than Previously Thought - CORVALLIS, Ore. - Stone tools and other artifacts unearthed from an archeological dig at the Cooper's Ferry site in western Idaho suggest that people lived in the area 16,000 years ago, more than a thousand years earlier than scientists previously thought. The artifacts would be considered among the earliest evidence of people in North America. The findings, published today in Science, add weight to the hypothesis that initial human migration to the Americas followed a Pacific coastal route rather than through the opening of an inland ice-free corridor, said Loren Davis, a professor of anthropology at Oregon State University and the study's lead author. "The Cooper's Ferry site is located along the Salmon River, which is a tributary of the larger Columbia River basin. Early peoples moving south along the Pacific coast would have encountered the Columbia River as the first place below the glaciers where they could easily walk and paddle in to North America," Davis said. "Essentially, the Columbia River corridor was the first off-ramp of a Pacific coast migration route. "The timing and position of the Cooper's Ferry site is consistent with and most easily explained as the result of an early Pacific coastal migration." Cooper's Ferry, located at the confluence of Rock Creek and the lower Salmon River, is known by the Nez Perce Tribe as an ancient village site named Nipéhe. Today the site is managed by the U.S. Bureau of Land Management.

Canadian Astronomers Determine Earth's Fingerprint - Two McGill University astronomers have assembled a "fingerprint" for Earth, which could be used to identify a planet beyond our Solar System capable of supporting life. McGill Physics student Evelyn Macdonald and her supervisor Prof. Nicolas Cowan used over a decade of observations of Earth's atmosphere taken by the SCISAT satellite to construct a transit spectrum of Earth, a sort of fingerprint for Earth's atmosphere in infrared light, which shows the presence of key molecules in the search for habitable worlds. This includes the simultaneous presence of ozone and methane, which scientists expect to see only when there is an organic source of these compounds on the planet. Such a detection is called a "biosignature". "A handful of researchers have tried to simulate Earth's transit spectrum, but this is the first empirical infrared transit spectrum of Earth," says Prof. Cowan. "This is what alien astronomers would see if they observed a transit of Earth." The findings, published Aug. 28 in the journal Monthly Notices of the Royal Astronomical Society, could help scientists determine what kind of signal to look for in their quest to find Earth-like exoplanets (planets orbiting a star other than our Sun). Developed by the Canadian Space Agency, SCISAT was created to help scientists understand the depletion of Earth's ozone layer by studying particles in the atmosphere as sunlight passes through it. In general, astronomers can tell what molecules are found in a planet's atmosphere by looking at how starlight changes as it shines through the atmosphere. Instruments must wait for a planet to pass - or transit - over the star to make this observation. With sensitive enough telescopes, astronomers could potentially identify molecules such as carbon dioxide, oxygen or water vapour that might indicate if a planet is habitable or even inhabited.

Daisies That Close At Night Have Camouflaged Petals To Protect Them From Herbivores - Researchers from Stellenbosch University, South Africa found that tortoises, one of the main herbivores of the daisies, were unable to distinguish the lower petal surfaces against a green leaf background. Tortoises prefer to eat protein-rich flowers over leaves, but when confronted with closed flowers, they showed no preference between them. When the researchers modelled the colours of the lower petal surfaces in the vision of other herbivores, they also found these colours to be indistinguishable from leaves. In contrast, species of daisy that do not close at night produced the same colouration on their lower petals as the upper petals exposed to pollinators. Plants face an evolutionary conflict between having flowers that attract pollinators while avoiding herbivores. Often plants defend themselves chemically, but this can have adverse effects on pollination. "When plants defend their flowers chemically, the pollination interactions can be negatively influenced. Our study shows a novel way in which flowers can avoid herbivores, without compromising pollination interactions." Says Dr. Jurene Kemp, lead author of the study. "These flowers can potentially circumvent the conflict of attracting both pollinators and herbivores by producing attractive colours on the surfaces that are exposed to pollinators (when flowers are open) and cryptic colours that are exposed when herbivores are active (when flowers are closed)."

Science Quote of the Month - "To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science." - Albert Einstein

What's New at the Museum:

Tales of the Alhambra - This ancient palace perched on a hill above the old city of Granada, Spain, has been the source of myths and legends for centuries. Often they are romantic tales, but occasionally tinged with horror. >Full Story

Mysterious Picture of the Month - What is this?

Ask the Curator:

DNA vs GENES - I would like to know the difference between DNA and genes. - Kamini

DNA stands for deoxyribonucleic acid. It is a double-stranded, helical nucleic acid molecule that encodes information hereditary information for almost all living organisms. A gene is one section of the DNA that controls a specific function or characteristic.

DNA is arranged like a twisted ladder with the up and down rails composed of sugar molecules and phosphate molecules connected to rungs made of either adenine and thymine or guanine and cytosine. One section of rail and a half rung is called a nucleotide and each nucleotide can be connected with others to make both sides of the ladder and to make the ladder longer. Because the half rungs (called bases) can be either adenine, thymine, guanine or cytosine, there are four different types of nucleotides. The order of the nucleotides on the ladder is important as this is how information is encoded into the DNA. It is not unlike the zeros and ones that encode information for computer program.

A group of consecutive nucleotides on the ladder that composes the instructions necessary to make one protein is called a gene. The protein molecule that the gene makes may control characteristics like a person's eye color, hair color, etc. On average a gene includes 3000 nucleotides, but for some simple proteins only a few dozen may be needed. Not all DNA nucleotides are part of a gene. There are lengthy intergenic regions in between most genes that either have no function or a regulatory function the scientists are only yet beginning to understand.

Humans are believed to have about 20,000 - 25,000 genes. More than ninety-nine percent of these genes are shared by all humans with only less than a percent involved in giving us all those traits that make use individuals. (In fact chimps, our closet biological relatives, have the 96% of the same DNA we do). Human DNA is also split up into unconnected sections called chromosomes. Humans have 23 pairs of chromosomes. A child gets one half of each pair from their mother and the other half from their father which is why a child might have their father's wide set eyes, but their mother's eye color. Chromosome number 23 is known as the sex chromosome because females carry two X types and males carry one Y and one X.

The DNA in a gene is divided up into two components. A "non-coding" section that simply indicates whether the gene is "on" or "off" (sometimes referred to the gene being "expressed" or not) and a "coding" section which contains the instructions to build the protein. The DNA does not build the protein itself but transcribes the information to RNA (Ribonucleic acid) to do the work. RNA looks and acts a lot like DNA, but is made up of only one half of the twisted ladder and uses a few alternate materials. In a few cases gene may not make a protein at all, but just RNA which is then used in another part of the protein synthesis operation.

Every cell in our body carries a copy of our DNA and parts of that DNA are very specific to each person, which is why it has become as important as fingerprinting to establish identity. Just a few cells left behind at a crime scene through a strand of hair can be enough to let police positively identify someone as the perpetrator. DNA can also predict if a person will get certain disease. For example, Tay-Sachs, which is a fatal disease often afflicting Eastern European Jews, has been shown to be the result a mutated and non-functioning HEXA gene. Other genes may not directly cause a disease, but increase the likelihood of a person getting ill. For example, researchers have shown that people with a nonfunctioning CREB gene are at an increased risk for anxiety and alcoholism.

The DNA actually looks like a super-tiny thread and is impossible to see without the use of an electron microscope. Typically it is curled up on itself so it can fit inside a microscopic cell. If you were to uncurl the DNA in a single cell, however, it would stretch out to about three feet in length and contain three billion base pairs.

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Transatlantic Flight - On September 2nd, in 1930, the first-nonstop airplane flight from Europe to the United States was complete by Captain Dieudonne Coste and Maurice Bellonte. The flight took 37 hours and originated in France and finished in Valley Stream New York.

In the Sky:

Harvest Moon - The night of September 14 will host a full moon traditionally called the "harvest" or "barley" or "corn" moon. The name comse from the light of the full moon shining in the fall allowing farmers to work late into the evening bringing in the crops.

Observed:

Giving People A 'Digital Identity' Could Leave Them Vulnerable To Discrimination, Experts Warn - Global efforts to give millions of people missing key paper documents such as a birth certificates a digital identity could leave them vulnerable to persecution or discrimination, a new study warns. Work is underway to use digital technology so refugees and others lacking vital legal papers can have access to services such as health and education. But this could also provide a new way for ethnic minorities to be discriminated against and marginalised by officials and governments if safeguards are not in place, according to new research. The World Bank estimates that over one billion people currently lack official identity documents - either because they never had it, or because they have lost it - and the United Nations Sustainable Development Goals include the aim to provide legal identity for all by 2030. Without identity documents people can have difficulty accessing many basic services including healthcare, social protection, banking or education. Asylum-seekers without documentary evidence of their identity and age may incur significant problems in acquiring legal status in a host country. However, the University of Exeter Law School study warns digital identity could allow for more "efficient" ways to discriminate against highly persecuted groups of people such as the Rohingya minority in Myanmar, as the technology would make their ethnic minority status more visible. Dr Ana Beduschi, who led the research, said: "Technology alone cannot protect human rights or prevent discrimination. Depending on how digital identity technologies are designed and used, they may also hinder the rights of those that they intend to benefit. Having a digital identity may make people without legal documentation more visible and therefore less vulnerable to abuse and exploitation. However, it may also present a risk for their safety. If the information falls into the wrong hands, it may facilitate persecution by authorities targeting individuals based on their ethnicity.

LGM:

Zeep and Meep are on a well deserved vacation. In their place we feature highlights from their past adventures.

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