Just Another Day on Aerosol Earth

Even if the air looks clear, it is nearly certain that you will inhale millions of solid particles and liquid droplets. These ubiquitous specks of matter are known as aerosols, and they can be found in the air over oceans, deserts, mountains, forests, ice and every ecosystem in between. via NASA https://ift.tt/2OYs9p0

Messier 20 and 21

The beautiful Trifid Nebula, also known as Messier 20, is easy to find with a small telescope in the nebula rich constellation Sagittarius. About 5,000 light-years away, the colorful study in cosmic contrasts shares this well-composed, nearly 1 degree wide field with open star cluster Messier 21 (bottom right). Trisected by dust lanes the Trifid itself is about 40 light-years across and a mere 300,000 years old. That makes it one of the youngest star forming regions in our sky, with newborn and embryonic stars embedded in its natal dust and gas clouds. Estimates of the distance to open star cluster M21 are similar to M20’s, but though they share this gorgeous telescopic skyscape there is no apparent connection between the two. In fact, M21’s stars are much older, about 8 million years old. via NASA https://ift.tt/2BI0maN

A World On Fire

The world is on fire. Or so it appears in this image from NASA’s Worldview. via NASA https://ift.tt/2o4ifa9

Comet Heart and Soul

The greenish coma of comet 21P/Giacobini-Zinner stands out at the left of this telephoto skyscape spanning over 10 degrees toward the northern constellations Cassiopeia and Perseus. Captured on August 17, the periodic comet is the known parent body of the upcoming Draconid meteor shower. Predicted to be at its brightest next month, the comet is actually in the foreground of the rich starfield, only about 4 light-minutes from our fair planet. Giacobini-Zinner should remain too faint for your eye to see though, like the colorful Heart and Soul nebulae near the center of the sensitive digital camera’s field of view. But the pair of open star clusters at the right, h and Chi Persei, could just be seen by the unaided eye from dark locations. The Heart and Soul nebulae with their own embedded clusters of young stars a million or so years old, are each over 200 light-years across and 6 to 7 thousand light-years away. They are part of a large, active star forming complex sprawling along the Perseus spiral arm of our Milky Way Galaxy. Also known as the Double Cluster, h and Chi Persei are located at about that same distance. Periodic Giacobini-Zinner was visited by a spacecraft from Earth when the repurposed International Cometary Explorer passed through its tail in September 1985. via NASA https://ift.tt/2w5P7n1

Space Station Flight Over Hurricane Lane

NASA astronaut Ricky Arnold photographed a massive storm in the Pacific Ocean during a flyover from the International Space Station. Arnold shared images on social media on Aug. 22, 2018, and wrote, „#HurricaneLane in the early morning hours near #Hawaii. The crew of the @Space_Station sends much aloha to everyone there.“ via NASA https://ift.tt/2BAhWNW

Asteroid Ryugu from Hayabusa2

This big space diamond has an estimated value of over 80 billion dollars. It’s only diamond in shape, though — asteroid 162173 Ryugu is thought to be composed of mostly nickel and iron. Asteroids like Ryugu are interesting for several reasons, perhaps foremost because they are near the Earth and might, one day in the far future, pose an impact threat. In the nearer term, Ryugu is interesting because it may be possible to send future spacecraft there to mine it, thus providing humanity with a new source of valuable metals. Scientifically, Ryugu is interesting because it carries information about how our Solar System formed billions of years ago, and why its orbit takes it so close to Earth. Japan’s robotic spacecraft Hayabusa2 just arrived at this one-kilometer wide asteroid in late June. The featured image shows surface structures unknown before spacecraft Hayabusa2’s arrival, including rock fields and craters. Within the next three months, Hayabusa2 is scheduled to unleash several probes, some that will land on Ryugu and hop around, while Hayabusa2 itself will mine just a little bit of the asteroid for return to Earth. via NASA https://ift.tt/2OYUFaf