#planetary science

Scientists have just found a sugar molecule in a giant molecular cloud called G+0.693-0.027, located near the center of the Milky Way. The sugar is called erythrulose, & on Earth it's also found in raspberries, fermented foods, some bacteria, & in cosmetics, especially self-tanners, because it reacts with skin proteins to create a browning effect. By itself, erythrulose is barely sweet. It's only 10-20% as sweet as sucrose. So if a teaspoon of sugar (4 g) tastes "normal," you'd need 5-10 teaspoons of erythrulose to get the same sweetness. But finding the sugar molecule is significant because sugars are essential for life; they are part of RNA, DNA, & cellular metabolism, they're needed for energy storage, & they are key to biochemical reactions. Finding them in space means life's building blocks don't need a planet to form, & they have been delivered to planets, including Earth, by comets & asteroids. The early Earth received huge amounts of organics in what is known as the Late Heavy Bombardment (LHB) between 4.1 and 3.8 billion years ago.

The LHB was frequent (thousands of years), huge & energetic. Explosions were equal to being hit by billions of nuclear bombs. The LHB is basically Earth's worst meteor shower ever. During this bombardment, Earth received water & organic molecules, like sugars, amino acids & alcohols, & created hot pools & chemical environments where life could have begun. If Earth received 0.5 and 50 million tons of erythrulose, that's 1 million to 100 billion pounds or 450,000 to 45 million metric tons. That's enough to coat the Earth with a thin layer of organic molecules. This is the first confirmed detection of erythrulose in the interstellar medium. Before this, scientists had found other sugars such as glycolaldehyde, glyceraldehyde, ribose, erythritol (a sugar alcohol that is also used in low-calorie artificial sweeteners), & other polyols & sugar-like molecules.

Microorganisms from our planet could survive on celestial bodies where water is present, such as Mars. That is the conclusion of Ph.D. candidate Tommaso Zaccaria after experiments with simulated space conditions. Our immune system reacts less effectively to pathogens that have undergone such a simulated space journey. According to his supervisors, his dissertation provides extraterrestrial insights that are also useful on Earth.

As humans, we live out our lives on a planet that is constantly sweeping through a cosmic ocean littered with ancient debris from the formation of the solar system. For the most part, our world glides silently through space, shielded by Earth's thin atmosphere. Occasionally, however, the rest of the universe reminds us of its presence with stunning, visceral clarity.

rare "super-puff" planets with densities lower than candy floss. The study—led by the University of Oxford, in collaboration with Université Côte d'Azur/Observatoire de la Côte d'Azur and the University of Birmingham—has been published in Monthly Notices of the Royal Astronomical Society. The two planets, named TOI-791 b and TOI-791 c, orbit an F7-type dwarf star located around 1,110 light-years from Earth in the southern constellation Volans. Although both planets are roughly the size of Jupiter, they are extraordinarily diffuse: TOI-791 b has a density of just 0.038 grams per cubic centimeter, while TOI-791 c has a density of 0.047 grams per cubic centimeter. By comparison, Jupiter's average density is 1.33 grams per cubic centimeter, around 28 to 35 times greater. Their densities are even lower than candy floss, which typically has a density of about 0.05 grams per cubic centimeter. In contrast, Earth's density is 5.5 grams per cubic centimeter.