2019 was another great year for science, with some amazing discoveries made. While most of the year’s news focused around things like the environmental crises gripping the world, lots of science was happening elsewhere too.

That said, plenty of discoveries were related to climate change, but not just our era. Scientists made some interesting discoveries about historic climate change, which will hopefully better help us understand our present situation. Here is a summary of some of the best scientific discoveries made in 2019.

1. Transmission of HIV reduced using new treatment

One of the best bits of news is the spread of HIV has been effectively stopped with the use of antiretroviral drugs. The results of an 8-year study conducted at the University College London and the University of Copenhagen found that the spread of HIV was prevented between HIV-positive and HIV-negative partners.

While this is incredible news, and is a massive blow in the face of one of the worst diseases to affect humanity, the question remains as to how these drugs will be provided to the most in need. The antiretroviral drugs are still expensive, and so will likely only be accessible to those in richer countries. However, this is an amazing step forward in the battle against this disease.

2. The asteroid that killed the dinosaurs has received more attention

There are 2 interesting pieces of news released this year that relate to the asteroid. The first is a team of researchers who have pieced together what happened on the first day of the asteroid strike. They’ve obtained this information by taking rock samples from the impact site, and used this data to build the bigger picture. In short, there was a massive tsunami and millions of tons of sulfur released into the atmosphere, which is what triggered the dinosaurs’ death.

The second study found that the asteroid also acidified the Earth’s oceans, which led to a change in their wildlife. The researchers behind the study used fossils of ancient foraminifera, single-celled organisms found in the oceans. Most importantly, this study will help scientists to understand the effects of ocean acidification, and what we can do about the problem.

3. The first ever plants were grown on the moon

Amazingly, humans first went to the Moon 50 years ago, but have never tried growing any plants on it. That was changed last year, however, when the Chinese sent an experiment up with their Chang’e 4 lunar probe. Even more amazingly, they actually managed to grow plants on the Moon. Their Lunar Micro Ecosystem experiment contained air, water, soil and different plants in an attempt to see what would grow.

After landing, the biosphere adjusted itself to a stable temperature and watered the seeds. Several of these seeds germinated within the next 12 days, including potato, rapeseed and cottonseed. However, the next day all of the seedlings died because their roots couldn’t tolerate the freezing lunar nights. This experiment is pretty impressive but was too short-lived to really produce any viable results.

4. The first black hole was photographed

Another one to add to the list of impressive firsts from 2019 is the first photograph of a black hole. It’s always worth remembering that every picture we’ve ever seen of a black hole is actually just an artist’s rendition. 

But not anymore. The image was captured by the Event Horizon Telescope Collaboration, which is a group of scientists from 40 countries. The black hole they photographed is the once at the center of M87, which is a supergiant galaxy found in the Virgo constellation. 

At 55 million light years away the black hole is too small to be seen by just one telescope, but the solution to this was quite amazing. The team used 8 telescopes across the globe, resulting in a virtual telescope effectively the size of the Earth. It’ll be interesting to see what they can capture next with this impressive technology.

5. Human climate change began much earlier than previously thought

Everyone sees human-based climate change as a relatively modern thing, but a study published last year confirmed this to not be the case. Researchers used a team of 100 archeologists and crowd-sourced information to put together a bigger picture of the issue. The findings were published in Science and make for quite an interesting read.

They found that by around 1,000BC humans had already had a significant impact on the climate. This was mainly because of hunter-gatherers changing to farming, but was affected by other pastoral activities, such as tree felling and mining. While this doesn’t affect the issue of modern climate change, it definitely helps us to understand our effect on this planet a little better.

6. Malaria infested mosquitos get around more than we thought

Malaria is currently one of the biggest problems affecting humanity. While many people’s efforts are focused elsewhere, mosquitos and the malaria virus they carry steadily kill millions of people each year, with almost no end in sight based on current methods. However that might now change with the release of a new study into their travel methods. The study was published in Nature, and will hopefully have a positive impact on the issue.

The study found that mosquitos can travel hundreds of miles by riding air currents to new locations. They found this by basically tying bug traps to helium balloons and sending them into the atmosphere. Most importantly, this study explains how malaria remains in dry areas that don’t suit mosquitos, but will also be helpful in fighting the spread of the disease in other parts of the world.

2019 might have been a bad year in some areas, but some of these studies prove that there’s still plenty to be done. Similarly, some of these studies prove we’re making good steps towards fighting some of humanity’s worst diseases. Hopefully 2020 will provide just as many interesting discoveries to push forward our understanding of the world.