Since October, the Hubble telescope has been tracking the first identified comet to arrive here from another star.

“We don’t know from where or when the comet started heading toward our Sun, but it won’t hang around for long,” a statement said.

“The Sun’s gravity is slightly deflecting its trajectory, but can’t capture it because of the shape of its orbit and high velocity of about 100,000 miles per hour.”

This week, scientists from Ohio State University said they’d developed a new gene-therapy technique by transforming human cells into mass producers of tiny nano-sized particles full of genetic material that has the potential to reverse disease processes.

“Though the research was intended as a proof of concept, the experimental therapy slowed tumour growth and prolonged survival in mice with gliomas, which constitute about 80 percent of malignant brain tumours in humans,” according to a statement from the university.

Meanwhile, researchers at Johns Hopkins Medicine say that early life exposure to dogs could lower the risk of developing schizophrenia via a positive on young immune systems.

Every day, there are so many announcements of new developments in science and medicine, it’s hard to keep track of them and impossible to report on them all. In the last decade – 2020 looming as it is – our understanding of the universe and the mini-universe inside our own bodies has expanded spectacularly.

Here are just some of the most significant discoveries and milestones:

2010: first self-replicating synthetic bacterial cell

Dr J. Craig Venter has always been in a hurry. In the 1990s he thought the US-government funded Human Genome Project was dragging its feet. So he decided to do it himself, and this began the first of many controversies. The two projects were honoured at the White House in 2000, and their completed maps were published in 2001. Some say the competition was a draw. Dr Venter said he did it faster and better.

Two years later, Dr Venter and his team built a synthetic virus from scratch in just two weeks. At the time, Dr Venter – then funded by the US Department of Energy – said he was working toward building designer bacteria that can pump out hydrogen fuel or gobble up greenhouse gases.

Blue colonies (top) indicate a successfully transplanted genome, with self-replicating bacteria revealed in an electron micrograph.
Credits (top to bottom): J. Craig Venter Institute; T. Deerinck and M. Ellisman/NCMIR, University of California, San Diego.

In 2008, Dr Venter – who by then ran his own research lab, the J. Craig Venter Institute – created the first synthetic bacterial genome, the largest man-made DNA structure a the time.

Dr J. Craig Venter has been described as a maverick, his work is said to be landmark, and the consequences of his research could potentially save the world, or wreck it. Photo: Wikipedia/Creative commons

In 2010, Dr Venter appeared to scare the hell out of fellow scientists with news that he’d developed the first living cell to be controlled entirely by synthetic DNA. The microbe, a genetically refitted version of a parasite that lives in goats and built from the ground up replicated itself more than a billion times, producing copies that contained and were controlled by the constructed, synthetic genome.

Dr Venter described the converted cell as “the first self-replicating species we’ve had on the planet whose parent is a computer”.

He told the BBC at the time: “I think (synthetic bacteria) are going to potentially create a new industrial revolution. If we can really get cells to do the production that we want, they could help wean us off oil and reverse some of the damage to the environment by capturing carbon dioxide.”

Some responses were carping, others agreed with Venter that his was a “landmark” study.

But there were terrified responses, too, such as this one voiced by Julian Savulescu, Oxford University ethics professor:

“The risks are unparalleled, we need safety evaluation for this kind of radical research and protections from military or terrorist misuse.”

Last month, Israeli scientists reported they had created a synthetic strain of the bacteria Escherichia coli that eats CO2 for energy rather than organic compounds like sugars and fats.

2011: First synthetic organ transplant

Surgeons in Sweden successfully transplanted a synthetic, tissue-engineered trachea – created from the patient’s stem cells – into a man with late-stage tracheal cancer.

University College London scientists created a scaffold built from porous polymer – this was then covered in stem cells from the patient’s bone marrow. The stem cells filled up the tiny holes in the scaffold until a fully formed, functioning trachea emerged.

Because it’s made from the patient’s cells, he won’t need to take anti-rejection drugs that are usually a hallmark (and burden) of post-transplant life.

Professor Paolo Macchiarini from Italy led the pioneering surgery, which took place at the Karolinska University Hospital in Sweden.

2012: Voyager 1 enters interstellar space

Voyager 1 was launched (as was its twin, Voyager 2) in 1977 to explore the outer planets in our solar system and became the first man-made object to enter interstellar space.

The Voyager craft famously took along a golden record containing music, images and spoken greetings from languages going back 6000 years – by way of introducing humans to whoever it might encounter along the way.

Some thought Voyager 1 would have died by now – but it continues to send data back to Earth.

Beyond the Bubble: The general locations of Voyager 1 and 2 are shown in this illustration at the edge of the heliosphere, the bubble created by solar wind. Illustration: NASA/JPL-Caltech

NASA couldn’t confirm that Voyager 1 had left the solar system until 2013, when it issued a statement:

“New and unexpected data indicate Voyager 1 has been traveling for about one year through plasma, or ionized gas, present in the space between stars. Voyager is in a transitional region immediately outside the solar bubble, where some effects from our sun are still evident.”

In December 2018, NASA confirmed that Voyager 2 had crossed the boundary of the solar system, called the heliopause, “where the tenuous, hot solar wind meets the cold, dense interstellar medium.”

NASA says that Voyager 2 carries a working instrument that will provide “first-of-its-kind observations of the nature of this gateway into interstellar space”.

2013: Cancer immunotherapy

The editors of Science magazine confessed some anxiety when they named cancer immunotherapy—harnessing the immune system to battle tumours— as Breakthrough of the Year.

“Did we risk hyping an approach whose ultimate impact remains unknown?” they wrote. “Were we irresponsible to label as a breakthrough a strategy that has touched a tiny fraction of cancer patients and helped only some of them?”

They largely awarded the accolade because of a series of clinical trials, over time, that “cemented its potential in patients and swayed even the skeptics”, citing stories of lives extended: “the woman with a grapefruit-size tumour in her lung from melanoma, alive and healthy 13 years later; the six-year-old near death from leukaemia, now in third grade and in remission; the man with metastatic kidney cancer whose disease continued fading away even after treatment stopped.”

But there was also “a sense of paradigms shifting” – citing dogged researchers who had engaged in “a careful decoding of basic biology that spanned many years”.

Dr James Alliosn, Nobel Prize winner for his ground-breaking work on cancer immunotherapy. Photo: University of Austin

They specifically named Dr James P. Allison, chair of Immunology at the University of Texas MD Anderson Cancer Centre, as a standout researcher. Dr Allison, along with Japanese immunologist Tasuku Honjo, were awarded the 2018 Nobel Prize in Physiology or Medicine for the discovery of immunotherapies for cancer.

“Allison and Honjo showed how different strategies for inhibiting the brakes on the immune system can be used in the treatment of cancer,” the Nobel Assembly at Karolinska Institutet in Stockholm said in a statement.

“The seminal discoveries by the two laureates constitute a landmark in our fight against cancer.”

2014: Gut microbes appear to rule our minds

This was the year when it became apparent that the bacteria in our digestive tract had a profound relationship with our wellbeing, but also, oddly, raised questions of human autonomy. Who or what is really in charge of us?

US researchers published a review of literature that indicated microbes “influence human eating behaviour and dietary choices to favour consumption of the particular nutrients they grow best on, rather than simply passively living off whatever nutrients we choose to send their way.”

In other words, our cravings for food – especially health-wrecking fats and sugars – serve the interests of the bacteria living in our gut rather than our bodies.

Escherichia coli, one of the many species of bacteria present in the human gut. Photo: Wikipedia/Creative commons

At that time, a number of reviews were published, including one in the Journal of Neuroscience that argued that the link between gut microbes and the brain – a relatively new concept – represented no less than a “paradigm shift” in neuroscience. It was suspected that neuro-degenerative diseases such as Alzheimer’s and Parkinson’s originated in the gut.

In 2017, scientists “discovered for the first time a functional link between bacteria in the intestines and Parkinson’s disease (PD). The researchers show that changes in the composition of gut bacterial populations – or possibly gut bacteria themselves – are actively contributing to and may even cause the deterioration of motor skills that is the hallmark of this disease.”

2015: Gravitational waves detected, Einstein was right

Albert Einstein predicted that when two bodies—such as planets or stars—orbit each other, they cause ripples in space. These ripples came to be known as gravitational waves – but did they really exist?

If so, they were invisible and fast, travelling at the speed of light – 299,792 kilometres per second – and they would squeeze and stretch anything in their path as they passed by.

Scientists spent 50 years looking for them.

On September 14, 2015, a very sensitive and very large instrument called LIGO (Laser Interferometer Gravitational-Wave Observatory) detected these ripples for the first time. They originated when two black holes crashed into one another 1.3 billion years ago – when the Earth’s most sophisticated life forms were bacteria.

The video below features scientists from LIGo telling the story of their discovery:

According to NASA, the LIGO detections represent “a much-awaited first step toward opening a whole new branch of astrophysics. Nearly everything we know about the universe comes from detecting and analysing light in all its forms across the electromagnetic spectrum – radio, infrared, visible, ultraviolet, X-Rays and gamma rays.

“The study of gravitational waves opens a new window on the universe, one that scientists expect will provide key information that will complement what we can learn through electromagnetic radiation.”

2016: Climate change, some good news and bad news

Portugal was entirely powered by renewable energy for four days, from May 7 to 11. That was exciting.

In September that year, CO2 in the Earth’s atmosphere passed 400 parts per million – the highest levels since the mid-Pliocene, three million years ago, when temperatures overall were 2 degrees to 3 degrees above pre-industrial temperatures – but more than 10 degrees hotter in the Arctic – and sea levels were at least 15 to 25 meters higher.

An essay from Yale School of Forestry & Environmental Studies reflected grimly on this milestone:

“The most recent Intergovernmental Panel on Climate Change (IPCC) report from 2013 made a more realistic estimate of what might happen, and what the temperature outcome would be.

“In the IPCC’s most pessimistic scenario, where the population booms, technology stagnates, and emissions keep rising, the atmosphere gets to a startling 2000 ppm by about 2250… That gives us an atmosphere last seen during the Jurassic when dinosaurs roamed, and causes an apocalyptic temperature rise of perhaps 9 degrees C (16°F).

“In the next-most-pessimistic scenario, emissions peak around 2080 and then decline, leading to an atmosphere of about 700 ppm and probable temperature increases of more than 3 degrees.

“In the most optimistic scenario, where emissions peak now (2010-2020) and start to decline, with humans actually sucking more carbon out of the air than they produce by 2070, the atmosphere dips back down below 400 ppm somewhere between 2100 and 2200 and the temperature increase is held under 1 degrees in the long term.”

Let’s choose the last one, right? Oops, we can’t. Too late.

CO2 emissions from fossil fuels are on track to again climb to a record high in 2019, according to a new report from the Global Carbon Project.

As the World Resources Institute noted: “The news was released as almost 200 nations gathered in Madrid, Spain to finalise rules of the Paris Agreement on climate change and prepare to enhance their national climate commitments in 2020.”

Except they failed to do anything but agree to talk some more.

2017: Best prospect ever for a cool new home

A newly discovered planet was the most promising yet in the search for extraterrestrial life, according to the Harvard astronomers who found it.

“A newly discovered ‘super-Earth’ orbiting in the habitable zone of a nearby small star, has catapulted itself to the top of that list,” they said in a statement published by the Harvard-Smithsonian Centre for Astrophysics.

Their confidence was founded in the unprecedented detail gleaned from the planet, named LHS 1140b, thriving in strange circumstances about 40 light years away.

Artist’s impression of the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth and may be the new holder of the title “best place to look for signs of life beyond the Solar System”. Illustration: ESO

LHS 1140b is 1.4 times the size of Earth, and 6.6 times heavier and denser. The greater density puts the planet into “super-Earth” class.

This was what has allowed LHS 1140b to have most likely retained much of its atmosphere. This would seem impossible considering the planet is much closer to its star than we are to our sun. There are only 25 days to its year.

The saving grace is that LHS 1140b’s sun is a red dwarf, about one-fifth the size of Earth, and much cooler. Instead of torching LHS 1140b, the star – known simply as LHS 1140 – provides only half the energy that Earth receives. Yet that’s still warm enough for the planet to exist in the Goldilocks Zone, the conditions that allow for liquid water and for some kind of life similar to our own.

Thanks to the recently retired Kepler space telescope, this has been the decade of exoplanets – the Kepler being launched in 2009 to look for them. In more than nine years of service, Kepler detected 2662 planets. Prior to its mission, about 400 had been detected.

2018: World’s first gene-edited babies created in China

A Chinese scientist found himself denounced by scientists from all over the world – and out of a job – after he claimed to have edited the genomes of twin girls at the embryo stage.

He made the announcement after the girls had been born – without a published journal paper to back up the claims.

Dr He Jiankui, an associate professor and genome-editing researcher at the Southern University of Science and Technology of China in Shenzhen, said that he impregnated a woman with embryos that had been edited to disable the genetic pathway HIV uses to infect cells.

In a video posted to YouTube, Dr He appears to be very happy with his work, advising that the girls are healthy and happy at home with their parents. He said that sequencing of the babies’ DNA has shown that the editing worked – and that he had altered only the target gene.

According to Nature, documents posted on China’s clinical-trial registry showed that Dr He used the CRISPR–Cas9 genome-editing tool to disable a gene called CCR5, which encodes a protein that allows HIV to enter a cell.

A review published earlier this year, found Dr He had committed a string of ethical breaches: engaging in work of questionable scientific value, unreasonable risk-benefit ratio, illegitimate ethics review, invalid informed consent, and regulatory misconduct.

The authors said the ethical failings of Dr He and his team “reveal the institutional failure of the current ethics governance system which largely depends on scientist’s self-regulation”.

2019: The HIV virus cured in mice

In a world first, researchers have eliminated HIV-1 DNA – the virus responsible for AIDS – from the cells and organs of living animals. Human trials could begin within a year.

In the US study, mice were cured of HIV by using a combination slow-acting retroviral drugs to suppress the virus, and a novel gene editing and gene therapy delivery system gene sequence that hunts the virus down – and removes it from the DNA in cells. It does so without collateral damage, notably poisoning.