These three bright nebulae are often featured on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula just left of center, and colorful M20 on the top left. The third emission region includes NGC 6559 and can be found to the right of M8. All three are stellar nurseries about five thousand light-years or so distant. Over a hundred light-years across, the expansive M8 is also known as the Lagoon Nebula. M20’s popular moniker is the Trifid. Glowing Read more »

NASA’s Green Propellant Infusion Mission, or GPIM, will prove a sustainable and efficient approach to spaceflight. via NASA https://go.nasa.gov/2Ejz6y2

How does your favorite planet spin? Does it spin rapidly around a nearly vertical axis, or horizontally, or backwards? The featured video animates NASA images of all eight planets in our Solar System to show them spinning side-by-side for an easy comparison. In the time-lapse video, a day on Earth — one Earth rotation — takes just a few seconds. Jupiter rotates the fastest, while Venus spins not only the slowest (can you see it?), but backwards. The inner rocky planets, across the top, most certainly underwent dramatic spin-altering collisions during the early days of the Solar System. The reasons Read more »

Why would clouds appear to be different colors? The reason here is that ice crystals in distant cirrus clouds are acting like little floating prisms. Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc lies parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are quite unusual to see. This Read more »

Students in Texas will have an opportunity next week to speak with a NASA astronaut aboard the International Space Station. from NASA https://go.nasa.gov/2JOrOpt via IFTTT

When Apollo 10 launched on May 18, 1969, it was the fifth launch of the Saturn V. via NASA https://go.nasa.gov/2WO33xp

Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid variable star, a class of stars whose brightness is used to estimate distances to nearby galaxies as one of the first steps in establishing the cosmic distance scale. As RS Pup pulsates over a period of about 40 days, its regular changes in brightness are also seen along its surrounding nebula delayed in time, effectively a light echo. Using measurements of the time delay and angular size Read more »

NASA has selected 11 companies to conduct studies and produce prototypes of human landers for its Artemis lunar exploration program. from NASA https://go.nasa.gov/2JoGi0a via IFTTT

NASA Administrator Jim Bridenstine will deliver remarks and speak to media Thursday, May 23, at Florida Institute of Technology in Melbourne. from NASA https://go.nasa.gov/2Ho6Axe via IFTTT

NASA is entering the final stage of testing its Unmanned Aircraft Systems Traffic Management (UTM) platform and invites media to learn more and watch drone demonstrations Tuesday, May 21, in Reno, Nevada. from NASA https://go.nasa.gov/2W5ICz6 via IFTTT