These are the most-read Science News stories of 2021

Blue jet lightning

The International Space Station spotted the origins of a bizarre type of upside-down lightning called a blue jet (illustrated) zipping up from a thundercloud into the stratosphere in 2019. The discovery ranked among Science News' most-read stories of 2021.


Science News drew over 21 million visitors to our website this year. Here’s a rundown of the most-read news stories and long reads of 2021.

Top news stories

1. Space station detectors found the source of weird ‘blue jet’ lightning

Instruments on the International Space Station detected the origins of an odd type of lightning called a blue jet. The bizarre bolt is sparked by a “blue bang” — a flash of bright blue light that may be brought on by the turbulent mixing of oppositely charged regions within a thundercloud (SN: 2/13/21, p. 14).

2. A newfound quasicrystal formed in the first atomic bomb test

The first atomic bomb test, in 1945, forged a peculiar, glassy material called trinitite — and within it, a rare form of matter called a quasicrystal. Quasicrystals’ atoms are arranged in an orderly structure like normal crystals, but the structure’s pattern doesn’t repeat (SN: 6/19/21, p. 12).

3. An Indigenous people in the Philippines have the most Denisovan DNA

The Ayta Magbukon people in the Philippines set the record for the highest known level of Denisovan ancestry — about 5 percent of their DNA comes from the ancient hominids. The finding suggests that several Denisovan populations independently reached Southeast Asia and interbred with Homo sapiens groups that arrived thousands of years later (SN: 9/11/21, p. 16).

4. Astronomers may have seen a star gulp down a black hole and explode

In a first, astronomers caught a glimpse of a rare double cosmic cannibalism: A star swallowed a black hole or neutron star, which then gobbled that star from within, resulting in an astonishing explosion (SN: 10/9/21 & 10/23/21, p. 6).

5. Frog skin cells turned themselves into living machines

Skin stem cells plucked from frog embryos organized themselves into miniature living robots, dubbed “xenobots,” that can swim, move around debris and even self-heal. Xenobots may one day serve a useful purpose, but ethical questions need to be considered (SN: 4/24/21, p. 8).

Top feature stories

1. New drugs that block a brain chemical are game changers for some migraine sufferers

A class of drugs that inhibits a neurotransmitter called calcitonin gene-related peptide is helping some patients who suffer from chronic, debilitating migraines (SN: 3/27/21, p. 16).

2. Einstein’s theory of general relativity unveiled a dynamic and bizarre cosmos

Albert Einstein’s general theory of relativity has served as the bedrock of our understanding of the cosmos. In the last 100 years, scientists have confirmed its most radical predictions, including black holes, gravitational waves and an expanding universe (SN: 2/13/21, p. 16).

3. Chemists are reimagining recycling to keep plastics out of landfills

No matter people’s dedication to sorting and recycling plastics, most still end up in landfills because the materials are too difficult to transform into useful new products. Some chemists are trying to change that (SN: 1/30/21, p. 20).

4. Psychology has struggled for a century to make sense of the mind

In the last 100 years, psychologists and other social scientists have dug into the muddy “science of us” and developed conflicting theories about human thought and behavior. From the messy, contentious research bloomed insights into what makes humans tick (SN: 8/14/21, p. 18).

5. Fossils and ancient DNA paint a vibrant picture of human origins

From the Taung Child to Lucy, the last century of paleoanthropology has sketched a rough timeline of how humans came to be. Scientists now agree that human evolution has its roots in Africa, but many mysteries in our history remain to be solved (SN: 9/25/21, p. 20).