Let's start with the numbers.

Around the world today, only 30 percent of researchers — and just 35 percent of students in STEM related fields — are women, according to the United Nations.

And yet, despite the barriers that women in science continue to face, they have revolutionized our world, conducting pioneering research and forging innovation the world over, from Katherine Johnson, whose calculations helped to put man on the moon, to Françoise Barré-Sinoussi, who discovered HIV.

Today marks 2020's International Day of Women and Girls in Science, an apt time to honor the contributions of women in science — and to make sure that there are even more of them in the future.

"If we are to be able to address the enormous challenges of the 21st century – from climate change to technological disruption – we will need to rely on science and the mobilization of all our resources," Audrey Azoulay, director general of UNESCO, said in a statement about the United Nations' commemorative day. "On the International Day of Women and Girls in Science 2020, UNESCO is calling on the international community, states, and individuals to work together so that equality in the sciences and other fields can finally become a reality. Humanity has everything to gain — and so does science."

How do we get there?

As U.N. Women executive director Phumzile Mlambo-Ngcuka points out, one of the first steps is breaking gender stereotypes linking science to masculinity, which can start with exposing younger generations to female role models leading the way in STEM.

This International Day of Women and Girls in Science, check out some of the women being tweeted about today. Take some time to learn about their contributions to science — and to us all.

1. Donna Strickland

With her Nobel Prize in Physics in 2018, Donna Strickland became the third female recipient of a physics Nobel in the prize's 118-year history. Strickland discovered a way to make high-intensity laser pulses, which eventually led to the techniques now used in corrective eye surgery and medical imaging.

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2. Tu Youyou

In 2015, Tu Youyou won the Nobel Prize in Physiology or Medicine for extracting a compound, called artemisinin, that can be used as combination therapy in the first line of defense against malaria. Her discovery has contributed to the survival and improved livelihood for millions of people.

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3. Marie Curie

An icon in the world of science, Marie Curie, the famous physicist and chemist, was the first woman to receive the Nobel Prize, in 1903, for her monumental research on radioactivity, resulting in the discovery of radium and polonium. She won again in 1911 for her continued investigation of the elements' properties, making her the first person (and only woman!) to win the prize twice.

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4. Mae Jemison

With her 1992 space voyage, Mae Jemison became the first black woman to travel in space. Before her time at NASA, she was a doctor for the Peace Corps. For her pioneering career, Jemison has been inducted into the National Women’s Hall of Fame, as well as the National Medical Association Hall of Fame. (Fun fact: She was also the first real astronaut to appear on Star Trek!)

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5. Françoise Barré-Sinoussi

Alongside colleagues, Françoise Barré-Sinoussi discovered HIV, the virus behind AIDS, in 1983. Since her discovery, she's continued to advocate for those living with HIV. Aspiring scientists, check out her advice below:

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6. Katherine Johnson

Katherine Johnson's calculations were fundamental in the space race, ultimately sending the first American into orbit. Johnson's historic role as a NASA scientist has become even more well-known in recent years thanks in part to the 2016 film, Hidden Figures, which told the story of Johnson and her colleagues. The year before, Johnson received the Presidential Medal of Freedom from former president Barack Obama. Last year, she was awarded the Congressional Gold Medal.

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7. May-Britt Moser

May-Britt Moser is a Norwegian psychologist and neuroscientist. She contributed to finding grid cells in the brain, which are crucial for the brain's ability to navigate. For the finding, Moser won the Nobel Prize in Physiology or Medicine in 2014.

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