From muscle loss to radiation exposure and the psychological effects of confinement, spaceflight takes a toll on those lucky enough to experience it.

European Space Agency flight surgeon Adrianos Golemis, who is responsible for the health of astronaut Thomas Pesquet during the SpaceX Crew-2 mission, shared some insights on the field of space medicine.

Q: What are the major health challenges of space?

A: If we talk about low Earth orbit where the ISS lies, you have almost zero gravity so that takes its toll on your bones and your muscles.

Radiation is a major issue, because here on the ground we are protected by the magnetosphere (magnetic field) and by the atmosphere, but if we go beyond, this protection goes away.

And of course we should not forget we have things that we are just beginning to understand: for example eye pathology (disease), or venous thrombosis (blood clots) that some healthy astronauts develop.

Looking to do some springtime astronomy? With temperatures warming up in the northern hemisphere in April through May, galaxy season is upon us. At dusk, the area in the Bowl of Virgo asterism rising in the east is rife with clusters of galaxies that spill over into the adjacent constellations of Coma Berenices and Boötes…

But this May, keep an eye out for a fuzzball interloper that is not a galaxy: Comet C/2020 R4 ATLAS.

Discovered on the night of September 12, 2020, by the prolific automated Asteroid Terrestrial Impact Last Alert System (ATLAS) sky survey based in Haleakala (ALTAS-HKO) and Mauna Loa (ATLAS-MLO) Hawaii, R4 ATLAS has proven to be an over-achiever. In fact, it was never initially predicted to top +10th magnitude… until a surprise outburst in late December 2020 shot it up 100-fold in brightness, from +18th to +13th magnitude. As of writing this, it sits at about +8th magnitude "with a bullet," and may top out +7th magnitude this week.

Understanding whether Mars was once able to support life has been a major driving force for Mars research over the past 50 years. To decipher the planet's ancient climate and habitability, researchers look to the rock record—a physical record of ancient surface processes which reflect the environment and the prevailing climate at the time the rocks were deposited.

In a new paper published in JGR: Planets, researchers on the NASA-JPL Mars Science Laboratory mission used the Curiosity rover to add another piece to the puzzle of Mars' ancient past by investigating a unit of rocks within Gale crater.

They found evidence of an ancient dune field preserved as a layer of rocks in Gale crater, which overlies rock layers that were deposited in a large lake. The rock remnants of the dune field are known today as the Stimson formation.

The findings help scientists understand surface and atmospheric processes—such as the direction the wind blew sand to form dunes—and potentially how Mars' climate evolved from an environment that potentially harbored microbial life, to an uninhabitable one.