ESA’s Trace Gas Orbiter Detects Green Airglow Around Mars

Many photographs taken from low-Earth orbit, especially from the Space Station while on the night side of Earth, show a thin line of green or yellowish light just above the limb of our planet. This is called airglow, and it’s caused by excited oxygen atoms high in the atmosphere releasing energy in the form of…

Solar Orbiter is Now Capturing the Closest-Ever Pictures of the Sun

(News from ESA) On June 15, 2020, the ESA/NASA Solar Orbiter spacecraft made its first close approach to the Sun (perihelion), coming within 77 million kilometers (48 million miles) of its surface—about half the distance between the Sun and Earth. Over the next week mission scientists will test the spacecraft’s ten science instruments, including the six…

NGC 6441: One of the Milky Way’s Most Massive Star Clusters

(NASA’s image of the day on June 5, 2020) Almost like snowflakes, the stars of the globular cluster NGC 6441 sparkle peacefully in the night sky, about 13,000 light-years from the Milky Way’s galactic center. Like snowflakes, the exact number of stars in such a cluster is difficult to discern. It is estimated that together…

Hypothesized First-Gen Stars Remain Unseen in Hubble Deep Views

(News from NASA) New results from the NASA/ESA Hubble Space Telescope suggest the formation of the first stars and galaxies in the early universe took place sooner than previously thought. A European team of astronomers have found no evidence of the first generation of stars, known as Population III stars, as far back as when…

ESA’s Solar Orbiter Will Fly Through the Tail(s) of Comet ATLAS

(News from ESA) ESA’s Solar Orbiter will cross through the tails of Comet ATLAS during the next few days. Although the recently launched spacecraft was not due to be taking science data at this time, mission experts have worked to ensure that the four most relevant instruments will be switched on during the unique encounter.

More Evidence for Plumes of Water on Jupiter’s Icy Moon Europa

All those worlds may be ours except Europa but that doesn’t make the ice-covered moon of Jupiter any less intriguing. Beneath Europa’s crisscrossed crust lies a tantalizing ocean somewhere in the neighborhood of 100 kilometers deep—which adds up to more liquid water than on the entire surface of the Earth. Liquid water plus a heat source(s) to keep it…

ESA Finds Liquid Water on Mars

Water has been found on Mars! (Yes, again.) In what’s turned into the biggest space news of the day, today ESA (and that’s pronounced “eesa”, you don’t need to spell it out) announced that the Italian-run radar experiment aboard its Mars Express orbiter has provided the first good evidence of liquid water present beneath the…

ESA Grabs Glimpses of Mars’ Groovy Moon

This animation is comprised of three images acquired by ESA’s Mars Express spacecraft on Sept. 12, 2017 with its High Resolution Stereo Camera (HRSC). It shows parts of the grooved and pitted surface of Phobos, the larger of Mars’ two natural satellites. The original images were captured in greyscale; I added color based on other…

Rolling Boulders on a Comet

See that big rock there? (It’s easy because there’s a big yellow arrow pointing to it.) That’s a 100-foot/30-meter wide boulder that was imaged sitting on the surface of Comet 67P/Churyumov-Gerasimenko by ESA’s Rosetta on May 2, 2015. Nine months later Rosetta captured another image of the same area in which that huge stone had…