New Delhi: An image of the black hole, the stuff of science fiction down the decades, was at the centre of a year that saw science breaching new frontiers with exciting firsts such as the development of a quantum computer that can outperform its classical counterparts and artificial embryos.
Cutting edge innovations in research and technology celebrated science and forwarded humankind's understanding of complex realities of the universe. The year will also be remembered as the year of testing biological and ethical limits in the laboratory, helping researchers find new avenues in the treatment of critical diseases.
In April, the International Event Horizon Telescope collaboration, consisting of a global network of radio telescopes, unveiled the first actual image of a black hole, a place in space where gravity pulls so much that even light cannot escape.
To produce the image, the researchers combined data from a network of radio telescopes to take simultaneous readings from around the world.
Science magazine named the image of the supermassive black hole situated at the centre of the Messier 87 galaxy, 54 million light years away, as the 2019 Breakthrough of the Year.
The imaging of the black hole is a fantastic revelation that is simultaneously a validation and a celebration of science, Ayan Banerjee, from the Indian Institute of Science Education and Research (IISER) in Kolkata, told PTI.
Although it does not uncover something that we did not know earlier, it does convert science fiction into science -- which is crucial for the acceptance of science in the daily lives of human beings, and the generation of future scientists, Banerjee said.
In a year that marked the 50th anniversary of the Apollo Moon landings, lunar exploration was high on the agendas of space agencies.
In January, China's Chang'e-4 probe became the first spacecraft to land safely on the far side of the Moon. Its rover Yutu-2 continues to roll across the dusty soils of Von Karman crater on the lunar body.
Other attempts to explore the Earth's natural satellite were not so successful.
In April, an Israeli-led effort to put the first private spacecraft on the Moon's surface ended in a crash landing. The same fate was met by India's ambitious Chandrayaan-2 Vikram lander in September.
The ongoing Mars missions returned a host of results. In April, NASA announced that its robotic Mars InSight lander had recorded a marsquake for the first time ever.
The marsquake' is the first recorded trembling that appears to have come from inside the planet, as opposed to being caused by the forces above the surface, such as wind.
There were many firsts in the micro world of laboratories too.
US researchers restored cellular function in 32 pig brains that had been dead for hours, opening up a new avenue in treating brain disease -- and shaking our definition of brain death to its core.
Announced in April in the journal Nature, the researchers at the Yale University School of Medicine devised a system roughly analogous to a dialysis machine, called BrainEx, that restores circulation and oxygen flow to a dead brain.
In another out-of-body experiment, scientists grew monkey embryos in a dish for nearly three weeks -- longer than primate embryos have ever been grown in the laboratory before.
The advance raised ethical concerns of whether lab-grown human embryos should be allowed to develop beyond 14 days, a restriction imposed in most countries.
In September, researchers at the University of Michigan in the US provided a possible circumvention of the 14-day limit by using human stem cells to make artificial embryos' that mimic the early development of a real human embryo.
Our stem cell structures that mimic embryos can help fill critical gaps in knowledge about early human development, and that could lead to a lot of good, Jianping Fu, an associate professor at Michigan, who led the study, said in a statement.
In October, Google took a quantum leap in computer science. Using its state-of-the-art quantum computer, called Sycamore, the tech giant claimed "quantum supremacy" over the most powerful supercomputers in the world by solving a problem considered virtually impossible for normal machines.
The quantum computer completed the complex computation in 200 seconds. That same calculation would take even the most powerful supercomputer approximately 10,000 years to finish, according to researchers from the University of California, Santa Barbara, who published their results in the journal Nature.
A fantastic discovery has been that of Google's 53 qubit quantum computer ('quantum supremacy), Banerjee said.
And for the first time in July, an artificial intelligence (AI) bot beat human champions at multiplayer poker.
The AI programme developed by Carnegie Mellon University in the US in collaboration with Facebook AI defeated leading professionals in six-player no-limit Texas hold'em poker, the world's most popular form of poker.
The AI, called Pluribus, defeated poker professional Darren Elias, who holds the record for most World Poker Tour titles, and Chris Ferguson, winner of six World Series of Poker events.
In August, researchers from Oxford University and IBM Research made the first-ever ring-shaped molecule of pure carbon in the lab by using an atomic-force microscope to manipulate individual molecules.
Carbon can be arranged in a number of configurations. For example when each of its atoms is bonded to three other carbon atoms, it's relatively soft graphite.
A ring of carbon atoms, where each atom is bonded to just two others, and nothing else has eluded scientists for 50 years. Their best attempts have resulted in a gaseous carbon ring that quickly dissipated.