2015 has heralded many exciting new developments in a broad range of scientific disciplines. Below are five news stories that have revolutionised their respective fields this year.
- The rise of CRISPR
CRISPR is a highly promising new gene editing technique that made headlines this the year. It is composed of an enzyme, called Cas9, which can cut DNA, and a collection of DNA sequences that direct Cas9 to the site of snipping. In April, scientists from Sun Yat-sen University in China declared that they had attempted to use CRISPR-Cas9 to repair a mutated version of the human beta-globin gene that causes an inherited blood disorder called beta thalassemia in nonviable human embryos. Publication of the paper shocked many people who feel that it is only a matter of time before the experiment is attempted on viable human embryos.
In December, an international summit was convened and determined there should be a voluntary ban on using CRISPR with germline cells as moral, ethical and safety concerns are in abundance. However, gene editing of somatic cells is still permitted. In 2016 a comprehensive report on the advisability of using CRISPR on germline cells will be released.
- A new insight into Pluto
The New Horizons spacecraft made its closest approach (12, 500km from the surface) to Pluto on July 14th, after a 5 billion kilometre journey that took almost nine and a half years. In September, NASA released high resolution images of Pluto and Charon, its largest moon. The photos have changed scientists’ previous perceptions about this little-studied planet.
One photo revealed a large expanse of rolling and grooved mountains that has been compared to a snakeskin. These mountain ridges are vertically aligned and are hundreds of meters tall. It is thought that they could have been formed by ice sublimating into gas upon sunlight reaching Pluto. Other photos have shown dunes (as Pluto has an atmosphere too thin for a significant wind to be present, it is unknown what has caused these), glacial lakes and water ice mountains. Such features establish that Pluto is a dynamic, complex world that differs from other planets orbiting the sun.
Less than 10% of the data captured by New Horizons have currently been downloaded, so Pluto may yet reveal more surprising features.
- New evidence points to possibility of water on Mars
In September this year, NASA made an announcement that water had been found on Mars. Data from the Mars Reconnaissance Orbiter showed that the seasonal dark streaks evident on the planet’s surface were coated with salts such as magnesium perchlorate and sodium perchlorate. The hydrated salts require liquid water to form, pointing its contemporary presence.
Such evidence for flowing water has exciting implications for the existence of life on Mars. Other evidence that Mars could perhaps support life include the discovery of a form of nitrogen, used on Earth to build biological molecules, in rocks on the Martian surface. In 2020, NASA plans to send a rover to Mars to collect and store rocks for analysis back on Earth, a mission which could provide even further evidence for life there.
Quarks are a fundamental unit of matter and, until now, they had been known to only gather in clumps of 3 or 2. However, ‘pentaquarks’, a clump made of 5 quarks, had been reported on several instances. In July, conclusive evidence for the existence of pentaquarks came from the Large Hadron Collider b detector. Researchers studied the disintegration of a clump of 3 quarks called a Lambda baryon and observed clumps composed of two up quarks, one down quark, one charm quark and one anti-charm quark. Such a result is particularly important as it confirms predictions made by Murray Gell-Mann in 1964 and can help physicists to better understand the strong nuclear force.
- The Ebola vaccine
Throughout late 2014 and early 2015, Ebola has ravaged West Africa, killing more than 11,000 people. 2015 has seen the development of two vaccines which could be stockpiled to prevent such damaging outbreaks happening in the future. One of the vaccines uses a live, replicating virus. When trialled in Guinean adults, none become infected with Ebola if vaccinated immediately after close contact with an infected person. The other vaccine uses a non-replicating virus. Although it has not been trialled to the same extent, it also appears promising. In 2016, both these vaccines should receive approval for use by the U.S. Food and Drug Administration.
Photo: Wikimedia Commons, Fraxinus Croat