cover of the November 21, 2020 issue

Lying low

Throughout Africa’s dry season, when mosquitoes are limited, malaria parasites in human blood turn their genes on and off to keep numbers low so infection does not set off alarm bells for the immune system, Erin Garcia de Jesus reported in “How malaria parasites conceal from the human immune system” ( SN: 11/21/20, p. 8).

“Possibly some protein in mosquito saliva informs the parasites, ‘Hello, I’m here to take you to your next victim,’ and the parasites change gene activity to ramp up their numbers,” she says.

E.T. phone home?

New methods are ramping up the look for alien intelligence, Maria Temming reported in “New search methods are increase the hunt for alien intelligence” ( SN: 11/21/20, p. 18).

Numerous readers were interested. The story “challenged my memory on the search for messages from aliens with [Temming’s] declaration: ‘So far, SETI researchers have not chosen up a single alien signal,'” reader David Cosson wrote. Possibly my memory is defective, however I recall the reporter as somebody called Steve Martin,” Cosson joked.

Reader Bob Johnson stays puzzled by some researchers’ efforts to find radio frequency signals. “It is extremely not likely other civilizations are, like us, going through the first 100 years of interaction development,” Johnson composed. “We need to be searching for signals in the ultraviolet, X-ray and gamma-ray frequencies. Although older technologies work, they are displaced by brand-new approaches. Looking for [radio frequency] signals from E.T. is analogous to listening for … modem tones as a sign of smart life.”

Watery skies

Water high up in Mars’ environment splits apart within a few hours, leaving hydrogen atoms to float away, Lisa Grossman reported in “Chemical reactions high in Mars’ environment rip apart water particles” ( SN: 12/ 5/20, p. 14).

Reader Lorenza Zamarron wondered what happens to oxygen. “Where does the oxygen go? If the oxygen is much heavier, does it fall back down to Mars? Is it damaged?”

A minimum of some oxygen breaks free of Mars’ gravity in a process called photochemical escape, states Shane Stone, a planetary chemist at the University of Arizona in Tucson. “Furthermore, some oxygen would inevitably be carried down toward and around the world,” Stone says. “Numerous researchers thought that atmospheric chemistry would, over very long period, balance the escape of hydrogen and oxygen to match the 2:1 ratio that these elements are found in water. However, some of us are reassessing this concept because of this discovery of water transportation directly to the upper atmosphere,” Stone says. That oxygen is slow to escape could partially discuss why the Red Planet is red. “Oxygen in the environment reacts with minerals on the surface area to produce iron oxide (rust), which is responsible for the reddish-orange color that is so indelibly Martian,” Stone states. “In other words, Mars is oxidized.”


In “Meet 5 Black researchers fighting for diversity and equity in science” ( SN: 12/19/20 & 1/2/21, p. 26), the name of a BlackAFinSTEM group member was insufficient. Her name is Anna Gifty Opoku-Agyeman.

Stay tuned

In 1970, researchers thought Earth’s magnetic pole turnarounds might be to blame for long-ago extinctions of single-celled organisms called Radiolaria (10 living species revealed listed below). No strong evidence of a direct link has actually turned up, Jonathan Lambert reported ( SN: 11/21/20, p. 4) in an upgrade to the article “Impacts of Earth’s magnetic field” ( SN: 11/21/70, p. 392). Reader Doug Pruner joked: “Radiolarian extinctions? Of course. The turnarounds triggered interference with their radios.”


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